Pipe cutting, filling and method and apparatus for push bending process

Abstract

The application provides a pipe cutting, filling and taking method and device for a push-bending forming process, which comprises the following steps: installing a pipe to be processed at a first position, and performing inclined angle cutting on both ends of the pipe by using a cutting device; installing the cut pipe at a second position, and filling rubber into the pipe by using a filling device; taking out the pipe after the filling is completed; performing push-bending forming; replacing the second position with a bent pipe profiling die; replacing the working end of the filling device with a flexible ball joint; placing the pipe after the push-bending forming into the bent pipe profiling die; and taking out the rubber block in the pipe after the push-bending forming by adjusting the pressure. The device integration of the cutting, filling and taking device replaces the traditional manual "punching and pressing" filling method and the "hooking and clamping" taking method, and solves the problems of inconvenience and low efficiency, and greatly improves the pipe blank manufacturing efficiency by more than 50%.

Description

Technical Field

[0001] This invention belongs to the field of pipe bending technology, specifically, it relates to a pipe cutting, filling and taking method and device for a push-bending forming process. Background Technology

[0002] The layout space for pipelines in spacecraft, especially launch vehicles, is becoming increasingly compact, leaving less and less room for choice in layout options. For pipeline system design, a smaller relative bending radius R / D (R is the bending radius of the bend, D is the outer diameter of the bend) for pipe bends (R / D≤1.5) and a longer straight section effectively reduce the number of welds, making them more valuable. This is especially true in the design of pressurization and delivery system pipelines, where thin-walled, small-bending-radius conduits are widely used to save space and reduce welds. Using thin-walled (t<1.5mm) pipes with small bending radii significantly saves space and reduces the weight of the pipeline system. This advantage is particularly important for launch vehicle pipeline systems, especially as the proportion of extremely small bending radius bends (R / D≈1) is increasing year by year, leading to increasing manufacturing difficulties for such products in actual production. Currently, the production of these conduits uses a process of half-pipe welding + straight pipe butt welding, a process heavily reliant on manual operation. The large number of structurally complex conduits rely solely on manual repair, welding, and assembly. This type of operation results in low manufacturing efficiency, low product quality stability, long processing cycles (more than 15 hours), and high processing costs, which affect the progress of aerospace product development and production.

[0003] Research indicates that small-radius tubes can currently be processed using a push-bending process. Push-bending is a simple and convenient operation, particularly effective in preventing thinning on the outer side of the tube during bending, achieving a bending radius of less than 1D. However, the push-bending process involves several steps: tube preparation before bending (cutting the tube blank and filling with rubber blocks), and removal of the rubber blocks after bending. Traditionally, these are done manually. Insufficient material filling during the filling process can lead to wrinkling during bending. Furthermore, the process is cumbersome, and scratches can occur on the surface of the parts, affecting the accuracy of the filling material and the forming quality, while also limiting the processing efficiency of push-bending.

[0004] The existing Chinese invention patent with publication number CN110814121B discloses a method for bending a small diameter pipe with a small bending radius and a small diameter pipe. This method is mainly for bending small diameter pipes using low melting point metal as a filling medium. During the bending process, a partition layer needs to be set to isolate the low melting point metal from the pipe blank. Subsequently, the metal needs to be heated and separated, but the filling effect is not flexible enough.

[0005] The existing Chinese invention patent with publication number CN100384558C discloses a thin-walled tube variable curvature push-bending process and mold. This method uses a hydraulic press as the loading method. There is no filling medium inside the tube during the push-bending process, which is not suitable for tubes with high precision requirements.

[0006] The existing Chinese invention patent with publication number CN109158458B discloses a method for hydraulically bending pipes using a composite filling medium. This method uses a composite approach of filling the inside of the pipe with polyurethane rings and the action of liquid, and then uses a pressure bending process for forming. However, the polyurethane ring filling is prone to creating local suspended areas, which is not suitable for pipes with small bending radii.

[0007] Therefore, there is a need for a device and method for cutting and filling small-bending-radius pipes, which can solve problems such as incomplete material filling, cumbersome operation, and scratches on the surface of parts that occur in the traditional manual filling process. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and apparatus for cutting and filling materials in a push-bending forming process. This solves the problems of existing push-bending pipe manufacturing processes, which rely on manual operation, suffer from incomplete material filling leading to wrinkles during the push-bending process, are cumbersome in operation, and have scratches on the surface of parts, thus affecting product quality.

[0009] The pipe cutting, filling and removing method and apparatus for push-bending forming process provided by the present invention includes the following steps: the pipe to be processed is horizontally fixedly installed in a first position, and the two ends of the pipe are cut at an angle using a cutting device; the cut pipe is then vertically fixedly installed in a second position, and rubber is filled into the pipe using a filling device, and the clamping force information is collected by a pressure sensor; the filled pipe is removed and push-bent, the fixing fixture used for vertically fixing the pipe in the second position is replaced with a pipe bending mold, the working end of the filling device is replaced with a flexible ball joint, the push-bent pipe is placed into the pipe bending mold, the flexible ball joint acts on the rubber block inside the push-bent pipe, and the rubber block inside the push-bent pipe is removed sequentially by adjusting the pressure.

[0010] In a preferred embodiment, a clamping device is provided at the first position, which acts on the middle section of the pipe to keep the pipe horizontal and expose both ends. According to the designed bevel angle, cutting lines are set at both ends of the pipe, and the cutting device performs bevel cutting along the cutting lines.

[0011] In a preferred embodiment, the filling device includes a movable top block with a pressure sensor, which can monitor the clamping force in real time and feed the clamping force information back to the controller for pressure control.

[0012] In a preferred embodiment, the inner diameter of the pipe bending mold is consistent with the diameter of the pipe after bending, which is used to limit the pipe after bending.

[0013] In a preferred embodiment, the flexible ball joint removes the rubber block by varying pressure, and the internal rubber block is pushed out of the pipe by the flexible ball joint sliding along the inner cavity of the bend. First, a small pressure is used to push out the rubber block near the opening of the pipe, and then a larger pressure is used to push out the inner rubber blocks one by one. At the same time, the pipe bending mold effectively supports the outer wall of the pipe.

[0014] In a preferred embodiment, lubricating oil is applied to the inside of the tube when filling it with rubber to reduce friction between the rubber block and the inner wall of the tube.

[0015] The pipe cutting and filling device for a push-bending forming process provided by the present invention includes a support frame, a cylinder, a movable top block, a pressure sensor, a clamping device, a laser cutter, a fixed fixture, a flexible ball joint, and a pipe bending profile mold. The support frame has a first position and a second position. The cylinder is fixedly positioned directly above the second position. The movable top block is detachably mounted on the output end of the cylinder. The flexible ball joint is detachably mounted on the output end of the cylinder. At least one set of pressure sensors is provided on the movable top block and the flexible ball joint. The clamping device is located at the first position, and the laser cutter operates at the first position. The fixed fixture and the pipe bending profile mold are interchangeably mounted at the second position.

[0016] In a preferred embodiment, the support frame is provided with a guide rail connecting the first position and the second position, and a sliding base plate is provided on the guide rail. The clamping device, the fixing fixture, and the pipe bending molding die are all detachably mounted on the sliding base plate by fasteners.

[0017] In a preferred embodiment, the support frame is provided with limiting baffles for positioning the sliding base plate at both the first and second positions.

[0018] In a preferred embodiment, the support frame is provided with lifting bolts for positioning the support frame.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention employs a pressure-controlled filling and dispensing device, which ensures more uniform material flow and compression during the rubber filling process. This avoids the problem of wrinkling during the bending process caused by improper gap control in traditional manual operation. It enables quantitative control of the compression force between rubber blocks, allowing for different rubber block compression forces to be used for pipes of different diameters. By adjusting the pressure sensor, it effectively prevents dents during the bending process of parts and effectively improves the bending quality of parts.

[0020] 2. The present invention uses interchangeable movable top blocks and flexible ball joints, which can realize the filling of more than 10 specifications of bent pipe blanks from φ52 to φ161, greatly improving the filling efficiency.

[0021] 3. This invention integrates cutting, filling, and material removal devices, replacing the inconvenience and low efficiency of traditional manual "pounding" filling and "hooking and clamping" material removal methods. It relies on the flexible ball joint sliding along the inner cavity of the curved pipe to push the internal rubber blocks out of the pipe. By adjusting the pressure, the rubber blocks near the opening of the pipe are first pushed out with a small pressure, and then the internal rubber blocks are pushed out one by one with a larger pressure. At the same time, the outer wall of the pipe is effectively supported by the conforming mold, which can realize the sequential removal of rubber blocks and ensure that the parts are not deformed, which greatly improves the pipe blank manufacturing efficiency by more than 50%.

[0022] 4. This invention utilizes mechanized operation and relies on pressure sensors to control the variable pressure of the rubber block inside the pipe. This effectively removes the rubber block and prevents excessive thrust from causing deformation of the parts. The contouring device can adjust the front and rear distances according to different bends, thereby improving the adaptability to different pipe materials. The flexible ball joint can penetrate deep into the pipe to apply force, improving the problem that the traditional method of relying on a hammer can only apply pressure at the end, making it difficult to remove the rubber block. This effectively avoids the risks of manual operation and achieves a significant improvement in the quality of the inner surface of the parts. Attached Figure Description

[0023] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram illustrating the overall structure of the pipe cutting and filling / retrieving device of the present invention. Figure 2 This is a schematic diagram illustrating the material handling device of the present invention; Figure 3 This invention primarily demonstrates the cutting process effect diagram; Figure 4 This is a schematic diagram illustrating the cutting process, which is the main feature of this invention. Figure 5 This invention primarily demonstrates the effects of the packing process; Figure 6The diagram illustrates the material handling process of this invention.

[0024] The diagram shows: 1. Support frame; 2. Lifting bolt; 3. Flexible ball joint; 4. Cylinder; 5. Movable top block; 6. Pressure sensor; 7. Clamping device; 8. Laser cutting machine; 9. Limiting baffle; 10. Laser cutting head; 11. Guide rail; 12. Fixture; 13. Pipe bending molding die. Detailed Implementation

[0025] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0026] like Figures 1 to 6 As shown, the pipe cutting and filling method for push-bending forming process provided by the present invention includes the following steps: The pipe to be processed is horizontally fixed in a first position, and both ends of the pipe are cut at an angle using a cutting device. The cut pipe is then vertically fixed in a second position, and rubber is filled into the pipe using a filling device, with the clamping force information collected by a pressure sensor 6. The filled pipe is then removed and push-bent. The fixing fixture 12 used for vertically fixing the pipe in the second position is replaced with a pipe bending mold 13, and the working end of the filling device is replaced with a flexible ball joint 3. The push-bent pipe is placed into the pipe bending mold 13, and the flexible ball joint 3 acts on the rubber block inside the push-bent pipe. The rubber block inside the push-bent pipe is then removed sequentially by adjusting the pressure.

[0027] This invention utilizes an integrated cutting, filling, and material handling method to prepare push-bending pipes through laser cutting and continuous flexible filling and handling. This solves the problems of incomplete material filling, cumbersome operation, and scratches on the surface of parts that occur in the traditional manual filling process. It effectively improves the filling accuracy and forming quality of push-bending pipes, while also increasing the processing efficiency of push-bending and reducing processing costs.

[0028] In this application's technical solution, to address the problem of cutting angle deviation caused by improper cutting during pipe cutting, a push-bending cutting component based on a reference clamping fixture is designed. To address the problem of insufficient filling of the rubber block during the filling process leading to wrinkling during push-bending, a push-bending clamping component based on a pressure sensor is designed. To address the problem of the rubber block becoming stuck inside the pipe after bending and being difficult to remove, an interchangeable, contour-following variable-pressure removal component is designed. In summary, this application's technical solution solves three major problems encountered in traditional push-bending forming processes: pipe dimensional deviation due to cutting angle deviation; wrinkling due to insufficient clamping force; and deformation during removal due to the rubber block becoming stuck inside the pipe, achieving rapid and high-quality processing.

[0029] Specifically, a clamping device 7 is installed at the first position. This clamping device 7 acts on the middle section of the pipe, keeping the pipe horizontal and with both ends exposed. According to the designed bevel angle, cutting lines are set at both ends of the pipe, and the cutting device performs bevel cuts along these lines. By clamping the pipe onto the clamping device 7 at the first position, the pipe's position is fixed, preventing cutting deviation. Then, the laser cutting machine 8 of the robotic arm cuts the dotted lines on the pipe. Since both ends of the pipe require angled cutting, this method achieves angled cutting at both ends, effectively preventing part cutting deviation. Traditional wire cutting, on the other hand, is prone to angled cutting deviations at both ends.

[0030] The filling device includes a movable top block 5 with a pressure sensor 6, which can monitor the clamping force in real time and feed the clamping force information back to the controller for pressure control. During rubber filling, lubricating oil is applied to the inside of the pipe to reduce friction between the rubber block and the inner wall of the pipe. During the pipe bending process, several rubber blocks need to be tightly bonded together before bending. If the rubber blocks are not tightly bonded, gaps can easily form between them during bending, leading to defects such as dents and depressions in the parts. Traditional manual clamping devices rely on human experience for clamping, making it impossible to control the clamping force. In this embodiment, a clamping module with a pressure sensor 6 is used, enabling quantitative control of the clamping force between the rubber blocks. Different clamping forces are applied to pipes of different diameters, and the pressure sensor 6 is adjusted to effectively prevent dents and other defects during the bending process. It should be noted that the technical solution of this application can use a gradient pressure method for filling.

[0031] The inner diameter of the pipe bending mold 13 is consistent with the diameter of the pipe after bending, and is used to limit the bending of the pipe. The flexible ball joint 3 removes the rubber block by varying pressure. The flexible ball joint 3 slides along the inner cavity of the pipe, pushing the inner rubber block out of the pipe. First, a small pressure is used to push out the rubber block near the opening of the pipe, and then a larger pressure is used to push out the inner rubber blocks one by one. At the same time, the pipe bending mold 13 effectively supports the outer wall of the pipe.

[0032] After bending, the pipe is complete and the rubber blocks inside need to be removed. Traditionally, this is done manually with a hammer, which can damage the inner wall of the pipe due to bending, and larger rubber blocks may be impossible to remove due to excessive internal friction. Using excessive hammer pressure can also deform and damage the parts. To address this, this application employs a variable pressure method using a flexible ball joint 3 to remove the rubber blocks. The flexible ball joint 3 slides along the inner cavity of the bent pipe, pushing the internal rubber blocks out. By adjusting the pressure, a smaller pressure is first used to push out the rubber blocks near the opening, and then a larger pressure is used to push out the remaining internal rubber blocks sequentially. Simultaneously, the bending mold 13 effectively supports the outer wall of the pipe, allowing for the sequential removal of the rubber blocks without deformation. In a preferred embodiment, wool felt is filled into the contoured inner cavity to increase friction and prevent scratches; the ejector pin is replaced with a ball joint, and the bent tube is fixed by the front pressure plate to prevent slippage; then, the end face of the column part is clamped by the step on the end face, and the internal rubber blocks are removed one by one by pressing down with the ball joint. After all the rubber blocks have been removed, the mold is opened and the part is taken out.

[0033] The pipe cutting and filling device for a bending forming process provided by the present invention includes a support frame 1, a cylinder 4, a movable top block 5, a pressure sensor 6, a clamping device 7, a laser cutter 8, a fixed fixture 12, a flexible ball joint 3, and a pipe bending profile mold 13. The support frame 1 is provided with a first position and a second position. The cylinder 4 is fixedly positioned directly above the second position. The movable top block 5 is detachably mounted on the output end of the cylinder 4. The flexible ball joint 3 is detachably mounted on the output end of the cylinder 4. At least one set of pressure sensors 6 is provided on both the movable top block 5 and the flexible ball joint 3. The clamping device 7 is located at the first position, and the laser cutter 8 operates at the first position. The fixed fixture 12 and the pipe bending profile mold 13 are interchangeably mounted at the second position.

[0034] In one feasible implementation, the clamping device 7 adopts a hinge structure, which can be adjusted within a range of 200mm to achieve compatibility with different pipe sizes.

[0035] as follows Figure 5 As shown, the movable top block 5 with pressure sensor 6 can monitor the clamping pressure in real time and feed the clamping pressure data back to the control computer for pressure control. During the clamping process, a linear pressure loading method is adopted, with the loading formula F=F1*N, where N is the number of rubber blocks, F1 is the clamping force of the first rubber block (adjusted according to different pipe diameters), and F is the total pressure. The rubber blocks are loaded through the top rod based on the pressure sensor. The movable top block 5 can be replaced according to the pipe size, with an adjustable range from φ52 to φ161. It can also be interchanged with a flexible ball joint 3 to remove the rubber block after the pipe is bent.

[0036] The inner diameter of the pipe bending mold 13 is consistent with the pipe diameter at φ1, and the step diameter is φ1-2t (t is the pipe wall thickness), which is used to limit the pipe after bending.

[0037] In a preferred embodiment, the support frame 1 is provided with a guide rail 11 connecting the first position and the second position. A sliding base plate is provided on the guide rail 11. The clamping device 7, the fixing fixture 12, and the pipe bending molding die 13 are all detachably mounted on the sliding base plate by fasteners. The support frame 1 is provided with limiting baffles 9 for positioning the sliding base plate at both the first and second positions.

[0038] In this application's technical solution, the sliding base plate can switch between a first position and a second position via the guide rail 11. When the sliding base plate reaches the first or second position, it is limited by the limiting baffle 9 and fixed with bolts to ensure positional accuracy. The laser cutting machine 8 includes a laser cutting head 10 for cutting the pipe. The cylinder 4 is fixedly installed directly above the second position via a gantry structure. The movable top block 5 and the flexible ball joint 3 can be detachably connected to the end of the output shaft of the cylinder 4 via a threaded connection or adapter, as is done in the prior art.

[0039] In a preferred embodiment, the support frame 1 is provided with lifting bolts 2 for positioning the support frame 1. This allows the entire device to be arranged in a suitable position.

[0040] as follows Figure 6 As shown, in a preferred embodiment, during the part removal process, a linear pressure loading method is adopted, with the pressure decreasing gradually to prevent excessive pressure from causing deformation of the part. The loading formula is F = F2 * N, where N is the number of rubber blocks, F2 is the part removal thrust of a single rubber block, and F is the total thrust. As the number of rubber blocks decreases, the thrust decreases gradually. Specifically, the thrust is applied to the rubber blocks by a push rod based on a pressure sensor.

[0041] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0042] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for cutting and filling tubular material in a push-bending forming process, characterized in that, Includes the following steps: The pipe to be processed is horizontally fixed in the first position, and the two ends of the pipe are cut at an angle using a cutting device. The cut pipe is then vertically fixed in the second position, rubber is filled into the pipe using a filling device, and the clamping force information is collected by a pressure sensor. After filling, the pipe is bent into shape. The fixing tool used for vertically fixing the pipe in the second position is replaced with a pipe bending mold. The working end of the filling device is replaced with a flexible ball joint. The bent pipe is placed into the pipe bending mold. The flexible ball joint acts on the rubber block inside the bent pipe. The rubber block inside the bent pipe is removed one by one by adjusting the pressure.

2. The pipe cutting and filling method for push-bending forming process according to claim 1, characterized in that, A clamping device is provided at the first position. The clamping device acts on the middle section of the pipe to keep the pipe horizontal and expose both ends. According to the designed bevel angle, cutting lines are set at both ends of the pipe, and the cutting device performs bevel cutting along the cutting lines.

3. The pipe cutting and filling method for push-bending forming process according to claim 1, characterized in that, The filling device includes a movable top block with a pressure sensor, which can monitor the clamping force in real time and feed the clamping force information back to the controller for pressure control.

4. The pipe cutting and filling method for push-bending forming process according to claim 1, characterized in that, The inner diameter of the pipe bending mold is consistent with the diameter of the pipe after bending, and is used to limit the pipe after bending.

5. The pipe cutting and filling method for push-bending forming process according to claim 1, characterized in that, The flexible ball joint removes the rubber block by varying the pressure. It slides along the inner cavity of the bend to push the internal rubber block out of the pipe. First, a small pressure is used to push out the rubber block near the opening of the pipe, and then a larger pressure is used to push out the inner rubber blocks one by one. At the same time, the pipe bending mold effectively supports the outer wall of the pipe.

6. The pipe cutting and filling method for push-bending forming process according to claim 1, characterized in that, When filling the rubber, apply lubricating oil to the inside of the pipe to reduce friction between the rubber block and the inner wall of the pipe.

7. A pipe cutting and filling / removing device for a push-bending forming process, characterized in that, Includes support frame, cylinder, movable top block, pressure sensor, clamping device, laser cutting machine, fixed tooling, flexible ball joint, and pipe bending profile mold; The support frame is provided with a first position and a second position. The cylinder is fixedly located directly above the second position. The movable top block is detachably installed at the output end of the cylinder. The flexible ball joint is detachably installed at the output end of the cylinder. At least one set of pressure sensors is provided on the movable top block and the flexible ball joint, respectively. The clamping device is positioned at the first position, and the laser cutting machine operates at the first position; The fixed fixture and the pipe bending profile mold can be installed interchangeably in the second position.

8. The pipe cutting and filling / removing device for push-bending forming process according to claim 7, characterized in that, The support frame is provided with a guide rail connecting the first position and the second position. A sliding base plate is provided on the guide rail. The clamping device, the fixing fixture and the pipe bending molding die are all detachably mounted on the sliding base plate by fasteners.

9. The pipe cutting and filling / removing device for push-bending forming process according to claim 8, characterized in that, The support frame is equipped with limiting baffles for positioning the sliding base plate at both the first and second positions.

10. The pipe cutting and filling device for push-bending forming process according to claim 7, characterized in that, The support frame is equipped with lifting bolts for positioning.

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