Tunnel pipe spinning forming process and equipment

Abstract

The present invention provides a tunnel pipe spinning forming process and equipment, relates to the field of spinning processing technology, and solves the problem of unstable tunnel pipe forming quality in the prior art. The present invention first fixes the head end of a blank tube to the main shaft end, uses the head end of the blank tube as a constraint end and the tail end as a free end in the axial direction, and causes a roller to axially feed toward the head end of the blank tube, performs thinning and forming spinning on the blank tube, and obtains a shell with well-controlled deformation degree; then, fixes the head end of the shell to the main shaft end, uses the head end of the shell as a constraint end and the tail end as a free end in the axial direction, and causes the roller to axially feed toward the tail end of the shell, ensuring good material fluidity, performs diameter reduction and forming spinning on the shell, and obtains a tunnel pipe with more stable forming quality.

Description

Technical Field

[0001] The invention relates to the technical field of spinning processing, in particular to a tunnel pipe spinning forming process and equipment. Background Art

[0002] The tunnel tube is a crucial component of a launch vehicle's propellant tank. Its primary function is to protect and insulate the cryogenic propellant delivery pipe and support the entire tank system. The tunnel tube is sheathed over the delivery pipe and located within the fuel tank. One end of the tunnel tube connects to the oxidizer tank, allowing the oxidizer to pass through the fuel tank and be delivered to the engine, preventing premature mixing of the fuel and oxidizer.

[0003] One of the main processing technologies for tunnel pipes is spinning. Generally, a thick-walled tube blank is installed on a spinning machine, and then the thick-walled tube blank is spun by a spinning wheel to obtain a thin-walled tube blank. After that, the thin-walled tube blank is put on a core mold with contoured corrugations, and the thin-walled tube blank is spun by a spinning wheel to reduce the diameter and obtain a tunnel pipe with several corrugations that imitate the core mold.

[0004] At present, the control of shape and size in the process of obtaining tunnel pipes through the spinning forming process is not ideal, resulting in unstable forming quality of the tunnel pipes. Summary of the Invention

[0005] The purpose of the present invention is to design a tunnel pipe spinning forming process and equipment to solve the problem of unstable tunnel pipe forming quality.

[0006] The present invention is achieved through the following technical solutions:

[0007] A tunnel pipe spinning process comprises the following steps:

[0008] The blank tube is sleeved onto a spinning mandrel mounted on the spindle of the spinning machine with its head end facing the spindle of the spinning machine and fixed to the spindle, with the head end of the blank tube serving as a constrained end and the tail end as a free end in the axial direction;

[0009] The spinning method is adopted in which the spinning wheel of the spinning machine is axially fed toward the head end of the blank tube, and the blank tube is thinned and shaped by spinning to obtain a shell;

[0010] The housing is sleeved onto a contoured core mold mounted on the spindle with its head end facing the spindle of the spinning machine and fixed to the spindle, with the head end of the housing serving as a restraining end and the tail end as a free end in the axial direction;

[0011] The shell is spun by reducing the diameter of the shell and forming the shell by a spinning method in which the spinning wheel of the spinning machine is axially fed toward the tail end of the shell to obtain a tunnel pipe.

[0012] A tunnel pipe spinning forming device, which includes a spinning machine, a spinning core mold, a profiling core mold and a pressing component and / or a thrust component connected to the spinning machine; the spinning machine includes a main shaft and a rotating wheel that can be radially or axially fed relative to the main shaft, the main shaft selectively connects the spinning core mold and the profiling core mold, the spinning core mold is used to be installed on the main shaft and used for sleeved blank tubes when performing thinning forming spinning, and the profiling core mold is used to be installed on the main shaft and used for sleeved shells when performing diameter reduction forming spinning; the main shaft end of the spinning machine can selectively fix the head end of the blank tube and the head end of the shell, the rotating wheel can axially feed the head end of the blank tube fixed to the main shaft to perform thinning forming spinning on the blank tube to obtain a shell, and the rotating wheel can axially feed the tail end of the shell fixed to the main shaft. The shell is subjected to diameter reduction spinning to obtain a tunnel tube; the pressing component and the rotating wheel are arranged in sequence along the main axis, the pressing component can move radially relative to the spinning machine to contact the outer peripheral wall of the blank tube, and can be synchronously axially fed relative to the rotating wheel, the pressing component is used to continuously apply radial downward pressure to the second elastically deformed area of ​​the blank tube located in front of the axial feed direction of the rotating wheel and adjacent to the first area that is in plastic deformation due to the extrusion of the rotating wheel during the thinning forming spinning process, and maintain the second area in an elastically deformed state; the thrust component is provided at the tail end of the spinning machine and is arranged in sequence along the main axis with the rotating wheel, the thrust component can move axially relative to the main axis to intermittently apply axial thrust to the tail end face of the shell during the diameter reduction forming spinning process.

[0013] The present invention has the following advantages and beneficial effects:

[0014] (1) The workpiece undergoes thinning forming spinning and diameter reduction forming spinning from the blank tube to the shell and then to the tunnel tube. During the thinning forming spinning process, since the head end of the blank tube is the constrained end that is axially constrained and the tail end is the free end that is not axially constrained, the material will flow toward the tail end of the blank tube when the roller feeds axially from the tail end to the head end of the blank tube. Since the forming area toward the tail end, which is located behind the roller feeding direction, is subjected to axial tensile stress and circumferential compressive stress, the axial tensile stress can suppress circumferential compression instability and better control the deformation of the blank tube to obtain a shell with well-controlled shape and size. In this way, the shape and size of the cylinder in the forming area can be ensured to a certain extent to control the fitting clearance between it and the spinning core mold, so that the spinning core mold can better support the forming area to prevent its deformation, and can also provide certain constraints for the deformation generated in the subsequent diameter reduction forming spinning process.

[0015] In the process of shrinkage forming spinning, the spinning object is a thinned and weakly rigid shell. Since the head end of the shell is the constrained end that is axially constrained, and the tail end is the free end that is not axially constrained, the material will flow more smoothly toward the tail end of the shell when the spinning wheel is axially fed from the head end to the tail end of the shell, which can avoid deformation or cracking caused by poor material flow to a certain extent.

[0016] Therefore, during the thinning forming spinning process, the material flow direction is first made opposite to the axial feed direction of the spinning wheel to obtain a shell with well-controlled deformation degree. Then, during the diameter reduction forming spinning process, the material flow direction is made the same as the axial feed direction of the spinning wheel to ensure good material fluidity, which can make the forming quality of the tunnel pipe more stable.

[0017] (2) The tunnel pipe spinning equipment is provided with a downward pressure component, which can apply radial downward pressure to the area of ​​the shell that has not yet formed a corrugated section but will form a corrugated section in front of the spinning wheel feed direction during the diameter reduction forming process to perform rounding treatment. This can eliminate the roundness change of the shell after the complete annealing treatment to a certain extent, and can improve the poor consistency of the wave height at different locations in the same corrugated section of the tunnel pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 The figure shows the thinning of the blank tube behind the axial feed direction of the spinning wheel during the thinning forming process;

[0020] Figure 2 It is a longitudinal cross-sectional diagram of the blank tube;

[0021] Figure 3 is a schematic longitudinal section of the shell;

[0022] Figure 4 The figure shows the situation in which the thrust component applies axial thrust to the rear end of the shell and the downward pressure component applies radial downward pressure to the area of ​​the shell that will form a straight segment during the diameter reduction forming spinning process;

[0023] Figure 5 The figure shows the situation in which the thrust component is separated from the rear end of the shell during the diameter reduction forming and the situation in which the pressing component applies radial downward pressure to the area of ​​the shell where the corrugated section will be formed;

[0024] Figure 6 It is a longitudinal section diagram of the split-flap mold short section;

[0025] Figure 7 It is a schematic diagram of the forming roller spinning the shell with reduced diameter;

[0026] Figure 8 It is a schematic diagram of the local structure of the forming wheel;

[0027] Figure 9 It is a partial schematic diagram of the tunnel tube;

[0028] Figure 10 It is a schematic diagram of the tilted setting of the lower pressure roller.

[0029] The following are marked in the figure:

[0030] 100. Blank tube;

[0031] 200, housing;

[0032] 300, tunnel pipe;

[0033] 41. Main shaft; 42. Thinning roller; 43. Forming roller;

[0034] 50. Spinning core mold;

[0035] 60. Profiling core mold; 61. Supporting core mold; 62. Forming core mold; 63. Split mold short section;

[0036] 70. Pressing component; 71. Pressing wheel frame; 72. Pressing roller;

[0037] 80. Thrust component; 81. Thrust wheel frame; 82. Thrust roller.

[0038] L0, main shaft axis; L1, lower pressure roller rotation axis. DETAILED DESCRIPTION

[0039] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other implementations obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0040] In the description of this application, it should be noted that, unless otherwise specified, “plurality” means two or more; the terms “upper”, “lower”, “left”, “right”, “inside”, “outside”, “front end”, “rear end”, “head”, “tail”, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0041] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the data used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than those illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects connected before and after are in an "or" relationship.

[0042] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this application depending on the specific circumstances.

[0043] On the one hand, the present invention provides a tunnel pipe spinning process, which can control the deformation during the spinning process to a certain extent and stabilize the forming quality of the tunnel pipe.

[0044] This process uses a spinning machine to complete the spinning of the cylindrical workpiece through thinning forming spinning and diameter reduction forming spinning, and finally obtains the tunnel tube 300. Basic, reference Figure 1 and Figure 4 The spinning machine includes a spindle 41, a spinning core die 50, a profiling core die 60, a spinning wheel, a tail plate (not shown), a discharge ring, etc. The spinning wheel is divided into a dedicated thinning spinning wheel 42 and a forming spinning wheel 43 corresponding to the thinning forming spinning and the diameter reduction forming spinning.

[0045] This process can achieve spinning of tunnel tubes of various sizes by adjusting parameters such as the spindle speed of the spinning machine and the feed rate of the spinning wheel. It is particularly suitable for spinning large-diameter, thin-walled tunnel tubes with an inner diameter of 500 mm or more and a diameter-to-thickness ratio of 100-150. The feed rate of the spinning wheel includes the radial feed rate and the axial feed rate of the spinning wheel.

[0046] The process mainly includes the following steps:

[0047] Step S1, preparation: select the qualified processing quality such as Figure 2 The blank tube 100 shown is pre-heat-treated to an O state (annealed state) to release residual stress and eliminate work hardening, resulting in improved plastic deformation capability. A thinning roller 42 is mounted on the roller frame of the spinning machine. A spinning core mold 50 is pre-installed and secured on the spindle 41 of the spinning machine. The tail end of the spinning core mold 50 is secured by a tail support plate.

[0048] The material of the blank tube 100 is aluminum alloy, and may also be titanium alloy, stainless steel, nickel alloy, etc.

[0049] Step S2, thinning and forming spinning: the blank tube 100 in the heat treatment state of O state is Figure 1 As shown, the blank tube 100 is mounted on the spinning core mold 50 with the head end facing the spindle 41 of the spinning machine and supported by the spinning core mold 50; the head end of the blank tube 100 is fixed to the spindle 41, while the tail end is not fixed, so that the head end of the blank tube 100 in the axial direction serves as a constrained end and the tail end serves as a free end.

[0050] During the thinning forming spinning process, the spindle 41 drives the spinning core mold 50 and the blank tube 100 to rotate; the spinning machine drives the thinning roller 42 to move to the starting position at the tail end of the blank tube 100, and then feeds radially from the starting position. After the thinning roller 42 reaches the set radial downward pressure on the blank tube 100, the spinning machine drives the thinning roller 42 to feed axially toward the head end of the blank tube 100 (that is, toward the spindle end of the spinning machine). After the thinning roller 42 reaches the set position axially, the spinning machine first drives the thinning roller 42 radially back to the starting height, and then drives the thinning roller 42 axially back to the starting position, completing the single-pass spinning process of the blank tube 100, and then the spinning machine drives the thinning roller 42 to perform the next pass spinning process on the blank tube 100. After three or four cycles, the thinning forming spinning of the blank tube 100 is finally completed to obtain a wall-thickness-reduced product. Figure 3 The housing 200 is shown.

[0051] The thinning roller 42 of the spinning machine uses high-force spinning during the thinning and forming spinning process, applying a radial downward pressure of 18 tons to the blank tube 100. Exemplarily, the radial downward pressure of the thinning roller 42 on the blank tube 100 during the thinning and forming spinning process reaches 18 tons. Exemplarily, the radial downward pressure of the thinning roller 42 on the blank tube 100 during the thinning and forming spinning process reaches 22 tons. Exemplarily, the radial downward pressure of the roller on the blank tube 100 reaches 20 tons.

[0052] Thinning and forming spinning adopts a three- or four-pass spinning process, with a thinning rate of 15% to 30% per pass. The spindle 41 speed is set to a constant speed of 20r / min-100r / min, and the feed rate of the thinning wheel 42 is set to 1.5mm / r-4mm / r. Among them, the feed rate of the thinning wheel 42 is 1.5mm / r-4mm / r, including the radial feed rate of the thinning wheel 42 of 1.5mm / r-4mm / r and the axial feed rate of the thinning wheel 42 of 1.5mm / r-4mm / r. In principle, the more passes used in thinning and forming spinning, the smaller the thinning rate per pass, which can reduce processing defects, but the efficiency will be lower.

[0053] For example, a three-pass spinning process is used in the thinning forming spinning process, wherein the thinning rate of each pass is approximately 30%, the spindle 41 rotates at a constant speed of 20r / min-100r / min, and the feed rate of the thinning wheel 42 is 1.5mm / r-4mm / r.

[0054] For example, the thinning spinning process uses a four-pass spinning process, where each pass has a thinning rate of 15% to 25%. The specific thinning rates of different passes can be roughly controlled to the same value, such as 20%, or the thinning rate of each pass can be adjusted between 15% and 25% based on the processing conditions of each pass. The spindle 41 rotates at a constant speed of 20 rpm to 100 rpm, and the feed rate of the thinning wheel 42 is 1.5 mm / r to 4 mm / r.

[0055] The speed of the spindle 41 is determined according to the diameter of the workpiece. For example, when the inner diameter of the blank tube 100 is φ580.6 mm and the wall thickness is 14 mm, the speed of the spindle 41 can be 20 r / min, 30 r / min, 40 r / min, 50 r / min, or 60 r / min. For example, when the inner diameter of the blank tube 100 is φ518 mm and the wall thickness is 13 mm, the speed of the spindle 41 can be 50 r / min, 60 r / min, 70 r / min, 80 r / min, or 100 r / min.

[0056] Step S3: The shell 200 obtained after thinning and spinning is subjected to a complete annealing treatment to eliminate internal stress and control deformation. The annealing treatment of the shell 200 should refer to the heat treatment experience of similar structures and materials to determine the heat treatment process parameters and process control to effectively control the deformation of the shell 200 and ensure that the performance and deformation of the shell 200 after heat treatment meet the requirements.

[0057] Step S4, after completing the thinning and forming spinning process of the blank tube 100, the spinning core mold 50 is removed from the main shaft 41 and replaced with Figure 4 and Figure 5 The profiling core mold 60 with multiple profiling corrugations shown in FIG. Wherein, the profiling core mold 60 includes a supporting core mold 61 and a forming core mold 62 with multiple profiling corrugations. Figure 5 As shown, the head end of the supporting core mold 61 is mounted on and fixed to the spindle 41 of the spinning machine, the tail end of the supporting core mold 61 is tightened by the tail top plate, and the forming core mold 62 is sleeved on the supporting core mold 61 with the head end facing the spindle 41 of the spinning machine. The head end of the forming core mold 62 is fixed to the spindle 41, and the tail end of the forming core mold 62 is limited to the supporting core mold 61 by the unloading ring. Replace the thinning wheel 42 on the wheel frame of the spinning machine with Figure 7 and Figure 8 The forming roller 43 shown in FIG.

[0058] Step S5, shrinkage forming and spinning: the fully annealed shell 200 is placed on the forming core mold 62 with the head end facing the main shaft 41 of the spinning machine and supported by the forming core mold 62. The head end of the shell 200 is fixed to the main shaft 41 by bolts, and the tail end is not fixed, so that the head end of the shell 200 serves as a constrained end and the tail end serves as a free end in the axial direction.

[0059] The diameter reduction forming spinning adopts a one- or two-pass spinning processing method, the spindle 41 speed is set to a constant speed of 20r / min-60r / min, and the feed rate of the forming wheel 43 is 2mm / r-10mm / r, among which the feed rate of the forming wheel 43 is 2mm / r-10mm / r, including the radial feed rate of the forming wheel 43 of 2mm / r-10mm / r, and the axial feed rate of the forming wheel 43 of 2mm / r-10mm / r.

[0060] During the shrinking forming spinning process, the main shaft 41 drives the profiling core mold 60 and the shell 200 to rotate; the spinning machine drives the forming roller 43 to move to the starting position at the head end of the shell 200, and then radially feeds from the starting position. After the forming roller 43 reaches the downward pressure on the shell 200, the spinning machine drives the forming roller 43 to axially feed toward the tail end of the shell 200 (that is, toward the tail end of the spinning machine). During the axial feeding process, Figure 4 、 Figure 5and Figure 7 As shown in the figure, the spinning machine drives the forming wheel 43 based on the waveform design to follow the waveform in the axial feed direction, gradually forming the linear segment and the corrugated segment of the reduced diameter on the shell 200. After the forming wheel 43 reaches the set position in the axial direction, the single-pass spinning process of the shell 200 is completed. If there is a subsequent spinning process, the spinning machine drives the forming wheel 43 to radially return to the starting height, and then axially return to the starting position to perform the next spinning process, and finally completes the reduced diameter forming spinning of the shell 200, and obtains the following Figure 9 Tunnel tube 300 is shown.

[0061] For example, a one-pass spinning process is adopted during the diameter reduction forming spinning process, the main spindle 41 rotates at a constant speed of 20 r / min, and the feed rate of the forming roller 43 is 10 mm / r.

[0062] For example, a one-pass spinning process is adopted in the process of shrinkage forming spinning, the main spindle 41 rotates at a constant speed of 60r / min, and the feed rate of the forming wheel 43 is 10mm / r, that is, the radial feed rate of the forming wheel 43 is 10mm / r, and the axial feed rate of the forming wheel 43 is 10mm / r.

[0063] For example, a two-pass spinning process is adopted in the process of shrinkage forming spinning, the main spindle 41 rotates at a constant speed of 40r / min, the feed rate of the forming wheel 43 is 6mm / r, that is, the feed rate of the forming wheel 43 is 6mm / r, and the axial feed rate of the forming wheel 43 is 6mm / r.

[0064] Preferably, regardless of whether one-pass spinning or two-pass spinning is used in the process of shrinkage forming spinning, the axial feed rate of the forming wheel 43 is 5mm / r-10mm / r, and at the same time, the rotation speed of the main shaft 41 is set to 20r / min-50r / min. In this way, the lower rotation speed of the main shaft 41 combined with the larger axial feed of the forming wheel 43 can avoid repeated squeezing of the forming wheel 43 at the same position of the shell 200 during the forming process, thereby avoiding cracking of the shell 200.

[0065] The workpiece of this tunnel tube spinning process, from the tube blank 100 to the shell 200 and then to the tunnel tube 300, undergoes thinning and forming spinning and diameter reduction spinning. During the thinning and forming spinning process, because the head end of the tube blank 100 is an axially constrained end and the tail end is a free end that is not axially constrained, the material will flow toward the tail end of the tube blank as the thinning roller 42 axially feeds from the tail end of the tube blank 100 to the head end of the tube blank 100. Because the forming area toward the tail end, located behind the feeding direction of the thinning roller 42, is subjected to axial tensile stress and circumferential compressive stress, the axial tensile stress can suppress circumferential compression instability, thereby better controlling the deformation of the tube blank 100 to obtain a shell 200 with well-controlled shape and dimensions. This can ensure the shape and dimensions of the cylindrical body in the forming area to a certain extent, thereby controlling the clearance between it and the spinning core mold 50, allowing the spinning core mold 50 to better support the forming area and prevent its deformation, and also provide a certain constraint on deformation generated during the subsequent diameter reduction spinning process.

[0066] During the diameter reduction forming spinning process, the spinning object is a thinned, weakly rigid shell 200. Since the head end of the shell 200 is an axially constrained constrained end and the tail end is a free end that is not axially constrained, the forming wheel 43 will flow more smoothly toward the tail end of the shell 200 when it is axially fed from the head end of the shell 200 to the tail end of the shell 200, which can avoid the problem of deformation or cracking caused by poor material flow to a certain extent. Therefore, during the diameter reduction forming spinning, no axial traction force is applied to the tail end of the shell 200 to ensure better forming without breakage, and the complex tail end traction equipment can be left, which greatly simplifies the tail end structure of the spinning machine.

[0067] Therefore, during the thinning spinning process, the material flow direction is first set opposite to the axial feed direction of the thinning roller 42 to obtain a shell 200 with a well-controlled degree of deformation. Then, during the diameter-reducing spinning process, the material flow direction is set to be the same as the axial feed direction of the forming roller 43 to ensure good material fluidity, thereby making the forming quality of the tunnel tube 300 more stable.

[0068] According to some optional embodiments, the total thinning rate of the blank tube 100 formed by spin forming into the tunnel tube 300 is 60% to 70%.

[0069] In some embodiments, the cylindrical tube blank 100 used as the raw material for the tunnel tube 300 is a 5A06 aluminum alloy Class I forging. The inner diameter of the tube blank 100 is φ580.6 mm and the wall thickness is 14 mm. The tube blank 100 is heat-treated to an O state before spinning. The wall thickness of the shell 200 obtained by thinning and spinning the tube blank 100 can range from 4.5 mm to 4.7 mm. The tunnel tube 300 obtained by reducing and spinning the shell 200 has an inner diameter of φ538 mm and an average thickness of 4.5 mm, resulting in a total thinning rate of approximately 67.86% and a diameter-to-thickness ratio of approximately 120.5. Because the tube blank 100 is thinned during spinning to form the tunnel tube 300, the length of the tunnel tube 300 is increased compared to the original tube blank 100, based on the principle of constant volume. In this embodiment, the length of the tube blank 100 is 790 mm, while the length of the tunnel tube 300 is approximately 1650 mm.

[0070] In some embodiments, the cylindrical tube blank 100 serving as the raw material for the tunnel tube 300 is a 5A06 aluminum alloy Class I forging. The tube blank 100 has an inner diameter of 518 mm and a wall thickness of 13 mm. The tube blank 100 is heat-treated to an O state before spinning. The shell 200 obtained by thinning and spinning the tube blank 100 can have a wall thickness ranging from 4.5 mm to 4.6 mm. The tunnel tube 300 obtained by reducing and spinning the shell 200 has an inner diameter of 500 mm and an average thickness of 4.1 mm, resulting in a total thinning rate of approximately 68.46% and a diameter-to-thickness ratio of approximately 122.95.

[0071] According to some optional embodiments, the length of the tunnel pipe 300 is greater than 1600 mm, for example, it can be 1650 mm in some embodiments, the wave pitch is 150 mm, the wave height is 21 mm, the straight section length is 72.8 mm, the transition zone radius at the corrugation root is 15 mm, the corrugation section radius is 26.75 mm, and the angle α between the center of the straight section and the corrugation section of the tunnel pipe 300 is 7.97°. In this embodiment, these parameters of the tunnel pipe 300 can be adjusted according to actual needs. For example, the wave height of the tunnel pipe 300 can be 20 mm to 23 mm, the wave pitch can be 140 mm to 160 mm, the transition zone radius at the corrugation root can be 14 mm to 15 mm, and the corrugation section radius can be 25 mm to 27 mm. Figure 9 As shown, the angle α between the straight and corrugated segments of tunnel tube 300 is 7.8°-8.1°. Parameters such as the wave height, the radius of the transition zone at the root of the corrugation, and the radius of the corrugation segment determine the shape of the corrugation, which matches the shape of the forming roller and the shape of the radial corrugation protrusions on the forming core mold 62.

[0072] According to some optional embodiments, the spinning machine can be a single-wheel or multi-wheel spinning machine, and the multi-wheel includes a double-wheel and a triple-wheel. In the thinning forming spinning and / or the diameter reducing forming spinning process, all the spinning wheels are used to perform the relevant spinning process. For example, Figure 1 、 Figure 4 and Figure 5 The figure shows the application of a multi-wheel spinning machine in a related spinning process, wherein the wheels are evenly spaced circumferentially along the spindle axis L0 of the spindle 41. During the thinning and / or diameter-reducing spinning processes, all the wheels advance and retract synchronously in the radial direction and in the axial direction.

[0073] According to some optional embodiments, since the shell 200 obtained in the thinning forming spinning process is fully annealed before the diameter reduction forming spinning process in step S5 is performed, the roundness of the shell 200 before and after the heat treatment will change to some extent, resulting in inconsistent wave heights at different positions of the same corrugated segment when the shell 200 is subjected to diameter reduction forming spinning.

[0074] Therefore, in order to improve the poor consistency of wave height at different locations in the same ripple segment, Figure 4 and Figure 5 As shown in FIG. 1 , in this embodiment, a pressing component 70 is introduced into the diameter reduction forming spinning process in step S5. Figure 5 In step S5, the pressing component 70 is used to apply radial downward pressure to the area of ​​the shell 200 located in front of the forming wheel 43 in the axial feeding direction where the corrugated section is to be formed to perform rounding processing.

[0075] Specifically, the area on the shell 200 where the corrugated section is to be formed corresponds to the radial corrugated protrusion of the forming core mold 62. During the synchronous axial feeding process of the pressing component 70 and the forming wheel 43, the pressing component 70 is radially fed when it reaches the area on the shell 200 where the corrugated section is to be formed, and radial downward pressure is applied to the shell 200 to cause plastic deformation in the radially pressed area of ​​the shell 200. During the axial feeding process, the roundness deviation of the shell 200 is continuously corrected. When the pressing component 70 leaves the radial corrugated protrusion corresponding to the forming core mold 62 on the shell 200, that is, when it moves to the area on the shell 200 where the straight section is to be formed, it radially retracts, and the pressing component 70 loses its ability to align the shell 200. Afterwards, the forming wheel 43 is axially fed to the area on the shell 200 that has been aligned in advance and forms the corrugated section in this area.

[0076] In this embodiment, during the shrinking spinning process, the pressing component 70 applies radial downward pressure to the area of ​​the shell 200 located in front of the forming roller 43 in the axial feed direction, where the corrugated section will not yet be formed, to perform a rounding process. This can, to a certain extent, eliminate the roundness variations that occur after the shell has been fully annealed, thereby improving the consistency of the wave heights at all locations within the same corrugated section of the tunnel tube 300, ultimately resulting in a tunnel tube 300 with more stable corrugation quality. Because the rounding and shrinking spinning of the shell 200 are performed simultaneously and in tandem, the time required for separate rounding of the shell 200 can be reduced.

[0077] Preferably, reference Figure 4 and Figure 5 In the process of synchronous axial feeding of the pressing component 70 and the forming wheel 43, after the pressing component 70 completes the rounding treatment of an area on the shell 200 where a corrugated segment is to be formed and moves to an area on the shell 200 where a straight segment is to be formed, the pressing component 70 radially retreats a distance and maintains contact with the shell 200. At this time, the pressing component 70 continues to apply a small radial downward force to the shell 200, and no longer causes plastic deformation to the shell 200. Instead, the area on the shell 200 pressed by the pressing component 70 is in an elastic deformation state, thereby maintaining the roundness of the area on the shell 200 where a straight segment is to be formed, reducing or avoiding radial outward deformation of the shell 200 at this point, and can ensure the axial fluidity of the material to a certain extent, reducing the risk of wrinkling during the spinning process.

[0078] During the shrinking forming and spinning process, the pressing component 70 can continuously apply radial downward pressure to the area on the shell 200 where the straight segment will be formed and maintain the area in an elastic deformation state, so as to limit the degree of radial bending and expansion of the area, ensure stable force, limit the lateral flow of material, reduce the risk of wrinkling, and ultimately obtain a tunnel tube 300 with more stable forming quality.

[0079] In some embodiments, the area of ​​the housing 200 subjected to the radial downward pressure by the pressing member 70 is axially spaced from the forming roller 43 by 10 mm to 50 mm. For example, the axial distance is 10 mm. For example, the axial distance is 50 mm. For example, the axial distance is 40 mm. The pressing member 70 has a certain width in the axial direction. This width can be 30 mm to 50 mm, for example, 30 mm, 35 mm, 40 mm, or 50 mm.

[0080] According to some optional embodiments, because the wall thickness reduction rate of the corrugated sections of the tunnel tube 300 is greater than that of the straight sections, particularly in the transition zone at the root of the corrugations, the reduction rate from the shell 200 to the tunnel tube 300 can reach as much as 10%. For example, a 5A06 aluminum alloy Class I forging with an inner diameter of 580.6 mm, a wall thickness of 14 mm, and a length of 790 mm can be spun to produce a tunnel tube 300 with an inner diameter of 538 mm and an average thickness of 4.5 mm. This results in a total thickness reduction rate of approximately 67.86%. While the straight sections are approximately 4.5 mm thick, the wall thickness of the corrugated transition zone can reach 4.2 mm. This significantly impacts the overall performance of the tunnel tube 300.

[0081] Therefore, if Figure 4 and Figure 5 As shown, in the embodiment, during the shrinking forming spinning process in step S5, a thrust component 80 is introduced. The thrust component 80 is used to intermittently apply axial thrust to the tail end face of the housing 200. Figure 4 As shown, the axial thrust is applied when the forming wheel 43 spins the corrugated section of the shell 200. Figure 5 In the illustrated embodiment, the forming roller 43 is spinning the straight section of the housing 200, and the thrust member 80 is now separated from the rear end surface of the housing 200. The axial thrust exerted by the thrust member 80 on the rear end surface of the housing 200 does not prevent the material of the housing 200 from flowing toward the rear end; it only affects this flow to a certain extent.

[0082] During the spin forming process, the thrust member 80 applies axial thrust to the tail end face of the shell 200 while the forming roller 43 forms the corrugated section. This shifts the tail end of the shell 200 from an unconstrained state to a partially constrained state. This temporarily reduces the tensile deformation of the shell 200 in the spinning section, thereby lowering the thinning rate. Ultimately, this ensures that the thinning rate of the tunnel tube 300 in the corrugated section is closer to that of the straight section. Therefore, the provision of the thrust member 80 ensures more stable forming quality for the tunnel tube 300.

[0083] It should be noted that the above-mentioned roller feed rate, unless it is clear whether it is radial feed rate or axial feed rate, includes both radial feed rate and axial feed rate. For example, if the roller feed rate is 1.5mm / r-4mm / r, it means that the axial feed rate of the roller is 1.5mm / r-4mm / r, and the radial feed rate is also 1.5mm / r-4mm / r.

[0084] On the other hand, the present invention provides a tunnel pipe spinning forming device, which includes a spinning machine, a spinning core mold 50 and a profiling core mold 60.

[0085] like Figure 1 and Figure 4 As shown, the spinning machine includes a main shaft 41 and a roller frame that can be radially or axially fed relative to the main shaft 41, and a thinning roller 42 and a forming roller 43 are selectively connected to the roller frame in a detachable manner. Figure 7 and Figure 8 As shown, the shaping portion of the shaping roller 43 is designed to imitate the waveform of the tunnel tube 300.

[0086] like Figure 1 and Figure 4 As shown, the spindle 41 is selectively and detachably connected to the spinning core mold 50 and the profiling core mold 60. Figure 1 As shown, the spinning core mold 50 is used to be installed on the main shaft 41 during thinning and forming spinning. The spinning core mold 50 is used to be sleeved on the blank tube 100 to provide necessary support for the blank tube 100. Figure 4 and Figure 5 As shown, the peripheral wall of the profiling core mold 60 is designed to imitate the desired tunnel tube 300 and is used to be installed on the main shaft 41 during the diameter reduction forming and spinning process. The profiling core mold 60 is used to be sleeved on the shell 200 to provide necessary support for the shell 200.

[0087] like Figure 1 and Figure 4 As shown, the spindle 41 of the spinning machine can selectively fix the head end of the blank tube 100 and the head end of the shell 200. During thinning and forming spinning, the thinning roller 42 can be driven by the spinning machine through the roller frame to axially feed the head end of the blank tube 100, whose head end is fixed to the spindle 41 or the spinning mandrel 50, to thin and form the blank tube 100 to form the shell 200. During diameter reduction spinning, the forming roller 43 can be driven by the spinning machine through the roller frame to axially feed the tail end of the shell 200, whose head end is fixed to the spindle 41 or the profiling mandrel 60, to reduce the shell 200 to form the tunnel tube 300.

[0088] According to some optional embodiments, Figure 4 and Figure 5 As shown, the tunnel pipe spinning forming device further includes a pressing component 70, which is arranged beside the spinning machine. The pressing component 70 is used in the diameter reduction forming spinning process and is used in conjunction with the forming roller 43.

[0089] The pressing component 70 and the forming roller 43 are arranged axially along the main shaft 41. The pressing component 70 is positioned axially closer to the rear end of the spinning machine than the forming roller 43. The axial spacing between the pressing component 70 and the forming roller 43 is between 10 mm and 50 mm, enabling the pressing component 70 to apply radial downward pressure to the area of ​​the housing 200 to be spun, 10 mm to 50 mm in front of the forming roller 43 in the feed direction. The area where the pressing component 70 presses down on the housing 200, axially along the main shaft 41, is between 30 mm and 50 mm.

[0090] The pressing component 70 can be connected to the feeding system provided on the spinning machine, so that the pressing component 70 can move radially relative to the spinning machine to contact the outer peripheral wall of the shell 200, and can be synchronously fed axially relative to the forming roller 43. The pressing component 70 can be fixed to the roller frame of the spinning machine through a bracket so that the movement of the pressing component 70 can be synchronously controlled by the roller frame. At the same time, the pressing component 70 is also separately configured with equipment such as hydraulic cylinders and electric cylinders, so that the pressing component 70 can be driven to make independent radial feed relative to the forming roller 43. Of course, the pressing component 70 can also be controlled independently by a separately provided feeding system to independently control its radial feed and axial feed, and the feeding system is fixed relative to the spinning machine, but attention should be paid to the synchronization with the roller frame. In the separate feeding system, the axial feed of the pressing component 70 can be controlled by a ball screw mechanism driven by a servo motor, and the radial feed of the pressing component 70 can be controlled by a hydraulic cylinder or an electric cylinder.

[0091] During the spin forming process, the pressing member 70 can radially press down the outer peripheral wall of the housing 200 by feeding downward, thereby applying radial downward force to the area of ​​the housing 200 located in front of the forming wheel 43 in the axial feed direction, where the corrugated section will be formed, to achieve roundness correction. The pressing member 70 can also radially press down the outer peripheral wall of the housing 200 by feeding downward, thereby applying radial downward force to the area of ​​the housing 200 located in front of the forming wheel 43 in the axial feed direction, where the straight section will be formed, to maintain its roundness.

[0092] like Figure 4 As shown, the number of the pressing components 70 is consistent with the number of the forming wheels 43, and the pressing components 70 and the forming wheels 43 are arranged in a one-to-one correspondence in the axial direction, so that the radial downward pressure can be applied to the shell 200 by the pressing component 70 in front of the axial feed direction of each forming wheel 43.

[0093] According to some optional embodiments, Figure 4 As shown, the pressing member 70 includes a pressing wheel frame 71 and a pressing roller 72 mounted on the pressing wheel frame 71. The pressing wheel frame 71 is used to be connected to a device that controls the axial feeding and radial feeding of the pressing member 70. The pressing roller 72 can contact the outer peripheral surface of the housing 200 through its wheel surface. When the main shaft 41 drives the housing 200 to rotate, the pressing roller 72 that contacts the outer peripheral wall of the housing 200 is subjected to friction and rotates accordingly.

[0094] In order to reduce the friction between the lower pressing roller 72 and the housing 200, the temperature of the area on the housing 200 that contacts the lower pressing roller 72 is lowered. Figure 10As shown, the rotation axis L1 of the lower pressing roller forms an angle θ with the main shaft axis L0, so that the lower pressing roller 72 and the housing 200 are in rolling friction fit. The greater the axial feed of the lower pressing roller 72, that is, the greater the axial feed of the forming roller 43, the greater θ.

[0095] The portion of the lower pressure roller 72 that provides the wheel surface may be a stainless steel wheel or a rubber wheel.

[0096] According to some optional embodiments, the tunnel pipe spinning apparatus further includes a thrust member 80 , which is disposed at the tail end of the spinning machine and is used in conjunction with the forming roller 43 during the diameter reduction spinning process.

[0097] The thrust member 80 is a device with axial feed capability, enabling axial movement relative to the spindle 41 to intermittently apply axial thrust to the tail end face of the housing 200 during the spin-forming process. Specifically, the thrust member 80 can be driven by a hydraulic cylinder, an electric cylinder, a lead screw, or a ball screw mechanism driven by a servo motor to move axially relative to the spindle 41.

[0098] like Figure 4 and Figure 5 As shown, the thrust component 80 is integrally mounted at the tail end of the spinning machine and arranged in sequence with the rollers along the main shaft 41. When the forming rollers 43 perform the reduction-forming spinning on the corrugated section of the housing 200, the thrust component 80 axially approaches the spindle end of the spinning machine and directly abuts against the tail end face of the housing 200, exerting a certain axial thrust toward the tail end of the housing 200. This thrust does not prevent the material of the housing 200 from flowing toward the tail end, ensuring that the material of the housing 200 flows smoothly toward the tail end during the reduction-forming spinning process.

[0099] According to some optional embodiments, Figure 4 and Figure 5 As shown, the thrust component 80 includes a thrust wheel frame 81 and a thrust roller 82 mounted on the thrust wheel frame 81. The thrust roller 82 can contact the tail end face of the housing 200 through its wheel surface. During the rotation of the housing 200, the thrust roller 82 contacts the tail end face of the housing 200 and is subjected to friction, causing it to rotate accordingly. The rotation axis of the thrust roller 82 is parallel to the tail end face of the housing 200 and intersects with the axis of the main shaft 41, so that the thrust roller 82 rolls and frictionally engages with the tail end face of the housing 200 through the wheel surface. The thrust wheel frame 81 is used to connect to a device that controls the axial feed of the thrust component 80.

[0100] The portion of the thrust roller 82 that provides the wheel surface may be a stainless steel wheel or a rubber wheel.

[0101] According to some optional embodiments, Figure 4 、 Figure 5and Figure 6 As shown, the profiling core mold 60 includes a supporting core mold 61 and a forming core mold 62. The forming core mold 62 is configured as a split mold. The forming core mold 62 includes a split mold short section 63 formed by circumferentially splicing multiple mold halves. Each split mold short section 63 is axially plugged into a forming core mold 62 that is profiling the tunnel pipe 300.

[0102] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0103] Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of the present application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in reverse order depending on the functions involved. For example, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Furthermore, features described with reference to certain examples may be combined in other examples.

[0104] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed by the present invention, which should be covered by the scope of protection of the present invention.

Claims

1. A tunnel tube spinning process comprising the following steps: The blank tube (100) is sleeved onto a spinning core mold (50) mounted on the spindle (41) with its head end facing the spindle (41) of the spinning machine and fixed to the spindle (41), with the head end of the blank tube (100) serving as a constrained end and the tail end serving as a free end in the axial direction; A spinning method is adopted in which the spinning wheel of the spinning machine is axially fed toward the head end of the blank tube (100), and the blank tube (100) is subjected to thinning and forming spinning to obtain a shell (200); The housing (200) is sleeved onto a contoured core mold mounted on the main shaft (41) with its head end facing the main shaft (41) and fixed to the main shaft (41), with the head end of the housing (200) serving as a restraining end and the tail end serving as a free end in the axial direction; the characteristics are: A spinning method is adopted in which the spinning wheel is axially fed toward the tail end of the shell (200), and the shell (200) is subjected to diameter-reducing spinning to obtain a tunnel tube (300); During the shrinkage forming spinning process, radial downward pressure is applied to the area of ​​the shell (200) located in front of the axial feed direction of the rotating wheel where the corrugated section will be formed to perform rounding treatment, and radial downward pressure is applied to the area of ​​the shell (200) located in front of the axial feed direction of the rotating wheel where the straight section will be formed to maintain roundness. When the rotating wheel performs spinning forming of the corrugated section on the shell (200), an axial thrust is applied to the tail end face of the shell (200), wherein the axial thrust does not prevent the material of the shell (200) from flowing toward the tail end.

2. The tunnel tube spinning process according to claim 1, characterized in that: The heat treatment state of the blank tube (100) before thinning and forming spinning is O state; And / or, the blank tube (100) is a 5A06 aluminum alloy Class I forging; And / or, the diameter of the tunnel pipe (300) is greater than or equal to 500 mm, and the diameter-to-thickness ratio of the tunnel pipe (300) is 100-150; And / or, the spinning machine is a single-wheel, double-wheel, or three-wheel spinning machine, and all the spinning wheels are used in the thinning forming spinning and / or the diameter reducing forming spinning process; And / or, the radial pressure exerted by the spinning wheel of the spinning machine on the blank tube (100) during the thinning and forming spinning process is 18t-22t; and / or, the total thinning rate of the blank tube (100) formed by spinning into the tunnel tube (300) is 60% to 70%; And / or, the thinning forming spinning process adopts a three-pass or four-pass spinning process, wherein the thinning rate of each pass is 15% to 30%, the spindle (41) rotates at a constant speed of 20 r / min to 100 r / min, and the feed rate of the spinning wheel is 1.5 mm / r to 4 mm / r; And / or, one or two passes of spinning are used in the process of the shrinkage forming spinning, the main shaft (41) rotates at a constant speed of 20 r / min-60 r / min, and the feed rate of the spinning wheel is 2 mm / r-10 mm / r.

3. The tunnel tube spinning process according to claim 2, characterized in that: The wall thickness of the shell (200) is 4.5 mm to 4.7 mm; the average wall thickness of the tunnel tube (300) is 4.5 mm; And / or, the tunnel tube (300) has a wave height of 20 mm to 23 mm, a wave distance of 140 mm to 160 mm, and a length greater than 1600 mm; And / or, the angle between the center of the straight section and the corrugated section of the tunnel tube (300) is 7.8°-8.1°.

4. The tunnel tube spinning process according to claim 1, characterized in that: The obtained shell (200) is first subjected to a complete annealing treatment and then subjected to a diameter reduction forming spinning treatment.

5. A tunnel pipe spinning device, characterized by: Used to implement the tunnel tube spinning process according to claim 1, the tunnel tube spinning equipment comprises a spinning machine, a spinning core mold (50), a contour core mold (60), and a pressing component (70) and / or a thrust component (80) connected to the spinning machine; The spinning machine comprises a main shaft (41) and a spinning wheel capable of radial or axial feeding relative to the main shaft (41), wherein the main shaft (41) is selectively connected to the spinning core mold (50) and the profiling core mold (60). The spinning core mold (50) is used to be installed on the main shaft (41) and used to sleeve the blank tube (100) when performing thinning forming spinning, and the profiling core mold (60) is used to be installed on the main shaft (41) and used to sleeve the shell (200) when performing diameter reduction forming spinning; The spindle end of the spinning machine can selectively fix the head end of the blank tube (100) and the head end of the shell (200); the spinning wheel can axially feed the head end of the blank tube (100) fixed to the spindle (41) to thin and spin the blank tube (100) to obtain the shell (200); the spinning wheel can axially feed the tail end of the shell (200) fixed to the spindle (41) to reduce the diameter of the shell (200) to obtain the tunnel tube (300); The pressing component (70) and the rotating wheel are arranged in sequence along the main shaft (41); the pressing component (70) can move radially relative to the spinning machine to contact the outer peripheral wall of the shell (200), and can be synchronously axially fed relative to the rotating wheel; the pressing component (70) is used to apply radial downward pressure to the area of ​​the shell (200) located in front of the axial feeding direction of the rotating wheel and where the corrugated section is to be formed during the shrinkage forming spinning process to perform a rounding process on the shell (200); The thrust component (80) is arranged at the tail end of the spinning machine and is arranged in sequence with the rotating wheel along the main shaft (41). The thrust component (80) can move axially relative to the main shaft (41) to apply axial thrust to the tail end face of the shell (200) during the shrinkage forming spinning process and when the rotating wheel performs spinning forming on the corrugated section of the shell (200).

6. The tunnel tube spinning equipment according to claim 5, characterized in that: When the tunnel tube spinning forming equipment includes the pressing component (70), the pressing component (70) is configured as a roller that is engaged in rolling friction with the housing (200) through a wheel surface.

7. The tunnel tube spinning equipment according to claim 5 or 6, characterized in that: When the tunnel tube spinning forming equipment includes the thrust component (80), the thrust component (80) is configured as a roller that engages with the tail end face of the housing (200) through rolling friction with the wheel surface.

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