High-pressure active elbow pipe blank machining positioning tool and method

Abstract

The application relates to the technical field of high-pressure movable bend processing, in particular to a high-pressure movable bend pipe blank processing positioning tool and method, which comprises a rotating mechanism used for controlling the included angle between the pipe blank and a saw blade; a linear motion mechanism installed on the rotating mechanism and used for controlling the axial displacement of the pipe blank relative to the saw blade on a sawing machine; and a positioning mechanism installed on the linear motion mechanism and used for positioning the thinnest and thickest positions of the pipe blank skin thickness. Through the tool, the quick clamping of the pipe blank with eccentric holes is realized, the operation is simple and convenient, and the clamping is firm and solid; in cooperation with the machine tool processing, the angle cutting processing of the movable bend pipe blank can be quickly realized, the problems of bend outer diameter collapse and bulging at the inner diameter are solved, and the movable bend processing efficiency and processing quality are improved.

Description

Technical Field

[0001] This invention relates to the field of high-pressure movable elbow processing technology, specifically a positioning tool and method for processing high-pressure movable elbow tube blanks. Background Technology

[0002] High-pressure flexible elbows are pipe fittings designed to accommodate the bending of pipelines when transporting high-pressure fluids. They are widely used in practical engineering, such as oilfield drilling, cementing, and fracturing operations. Due to their special working environment and requirements, strict dimensional accuracy is required. Most existing high-pressure elbow manufacturing processes use tube blank bending. During this process, the outer wall is subjected to tension and the inner wall to compression, forcing the outer wall thickness to decrease and the inner wall thickness to increase. This necessitates further finishing of the straight section and both ends of the bend, resulting in a large workload. Furthermore, the 90° bend in the tube blank makes processing extremely difficult, affecting the dimensional accuracy after forming.

[0003] Therefore, existing patents propose an eccentric design scheme for the tube blank, forming a tube blank with a structure that gradually thickens from the inner wall to the outer wall. For example, in the non-uniform wall thickness tube bending forming method published in CN108506588A, to ensure uniform wall thickness, the center hole is eccentrically machined before manufacturing. However, in actual manufacturing, although the center hole is eccentrically machined, the metal does not have uniform flowability during bending, resulting in different flowability in different parts. Simulation experiments show that... Figure 1 Without an additional pushing mechanism, under the action of the bending die mechanism alone, after the tube blank is bent, due to compression at the inner diameter and tension at the outer diameter, the tube wall near the inner diameter is longer than the tube wall near the outer diameter due to metal flow under compression. That is, after bending, the tube length gradually increases from the thick-walled side to the thin-walled side. At the same time, due to tension, the outer wall bends are prone to material shortages and incomplete outer wall filling. Figure 2 Under the combined action of the pipe bending machine's push mechanism and bending die mechanism, during bending, the inner wall is pushed when bending, and material is easily piled up at the inner wall bend, resulting in excessive wall thickness. The large end of the tube blank is generally processed into the female end of the bend, and the small end is generally processed into the male end of the bend.

[0004] Therefore, in response to this problem, through continuous simulation experiments and in-plant processing experiments, it was found that before the bending and forming process, the small end of the tube blank can be chamfered first, so that the length of the tube blank from the outer wall to the inner wall gradually decreases. With the addition of the pushing action, the problem of material accumulation and bulging at the inner wall bend and material shortage and collapse at the outer wall bend can be solved after the tube blank is bent. However, since the outer surface of the tube blank is circular, it is very difficult to measure and position the thinnest and thickest parts of the eccentric tube blank, and the chamfering of the end of the eccentric tube is very difficult. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a high-pressure movable elbow tube blank machining positioning tooling and method that can achieve eccentric tube blank positioning and fixing, facilitating corner cutting machining.

[0006] The technical solution adopted by this invention to solve its technical problem is: A high-pressure movable elbow tube blank processing positioning fixture includes a rotating mechanism for controlling the included angle between the tube blank and the saw blade; a linear motion mechanism mounted on the rotating mechanism for controlling the axial displacement of the tube blank relative to the saw blade on the sawing machine; and a positioning mechanism mounted on the linear motion mechanism for positioning the tube blank at its thinnest and thickest positions.

[0007] As a preferred embodiment, a further technical solution of the present invention is: Preferably, the positioning mechanism includes a positioning seat and a support seat spaced apart along the linear motion direction. The support seat is machined with a V-shaped groove for supporting the tube blank. The positioning seat is machined with a limiting groove on the side near the support seat that is adapted to the large end of the tube blank. An eccentric shaft adapted to the eccentric hole of the tube blank is provided in the limiting groove.

[0008] Preferably, the eccentric shaft and the limiting groove are eccentrically arranged in the horizontal direction.

[0009] Preferably, the rotating mechanism includes a support platform, on which a rotating seat and a locking member for locking the rotating seat are provided. A guide seat is provided on the rotating seat, and a rotating handle is provided on one side of the guide seat. A linear motion mechanism is slidably connected to the guide seat.

[0010] Preferably, the rotating seat includes a circular tray with a rotating column on it. A guide seat is mounted on the rotating column, and the cross-sectional dimensions of both the guide seat and the circular tray are larger than the cross-sectional dimensions of the rotating column. A column hole is provided on the support platform corresponding to the rotating column, and an installation groove is provided on the bottom surface of the support platform on the outside of the column hole corresponding to the circular tray. The locking element is a locking bolt. Bolt holes are provided on the left and right sides of the column hole on the support platform. The locking bolt is installed in the bolt holes, passes through the support platform, and the bolt head of the locking bolt is located on the lower side. The bolt shank end of the locking bolt abuts against the bottom surface of the guide seat, and when the circular tray is tightly pressed against the top surface of the installation groove, the angle of the rotating seat is locked.

[0011] Preferably, an observation slot is provided on the side of the support platform, the observation slot is connected to the installation slot, a scale line is provided on the side of the circular tray, and an indicator line is provided on the side of the support platform above the observation slot.

[0012] Preferably, the circular tray and the rotating column are connected and fixed by a first hex bolt.

[0013] Preferably, the linear motion mechanism includes a horizontally arranged sliding seat with two dovetail blocks spaced apart on its bottom surface. A dovetail groove is provided on the guide seat corresponding to the dovetail blocks. The sliding seat is slidably connected to the guide seat through the dovetail blocks and the dovetail groove. A vertical baffle is provided on the left side of the sliding seat, and a shaft hole is provided at the lower part of the vertical baffle. A connecting shaft is rotatably connected to the shaft hole through a bearing. A rotating handle is provided on the left side of the connecting shaft, and a lead screw is provided on the right side. The lead screw is located on the lower side of the sliding seat and between the two dovetail blocks. A straight groove is also provided on the guide seat, with the straight groove located in the middle of the dovetail groove. A limit block is fixed in the straight groove, and a guide threaded hole is provided on the limit block. The lead screw is threadedly connected to the limit block through the guide threaded hole.

[0014] Preferably, the rotating column and the guide seat are an integral structure, and the rotating column and the guide seat are provided with through holes, which pass through the bottom surface of the rotating seat and the straight groove; the limiting block and the guide seat are connected and fixed by a second internal hex bolt.

[0015] This invention also discloses a method for machining and positioning a high-pressure movable elbow tube blank, comprising: first, installing a high-pressure movable elbow tube blank machining and positioning fixture on a machine tool; then, installing the tube blank on a positioning mechanism, with the positioning mechanism limiting the tube blank; then, adjusting a rotation mechanism to adjust the included angle between the tube blank and the saw blade to a preset angle; and finally, adjusting a linear motion mechanism to slide the tube blank to the underside of the saw blade for corner cutting.

[0016] The present invention, which adopts the above technical solution, has the following prominent features compared with the prior art: This fixture enables rapid clamping of tube blanks with eccentric holes. The positioning seat and support seat limit the thinnest and thickest positions of the eccentric tube blank. The linear motion mechanism facilitates adjustment of the distance between the eccentric tube blank and the saw blade, and the rotation mechanism facilitates adjustment of the included angle between the eccentric tube blank and the saw blade. The operation is simple and convenient, and the clamping is firm and secure. When used with a machine tool, it can quickly perform corner cutting on movable bend blanks, making the bent end of the movable bend flatter, and the wall thickness at the bend and the small end more uniform, thus improving the processing efficiency and quality of movable bends. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the tube blank after bending under the action of the bending die mechanism in the existing technology; Figure 2 This is a schematic diagram of the tube blank after bending under the combined action of the jacking mechanism and the bending die mechanism in the existing technology; Figure 3 This is a schematic diagram of the tube blank shape after the tube blank is chamfered before the bending process in an embodiment of the present invention; Figure 4 This is a schematic diagram of the high-pressure movable elbow tube blank processing and positioning fixture in an embodiment of the present invention; Figure 5 This is a schematic diagram of the rotating mechanism in an embodiment of the present invention; Figure 6 This is a schematic diagram of the support structure in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the rotary seat in an embodiment of the present invention; Figure 8 This is a cross-sectional view of the rotary seat in an embodiment of the present invention; Figure 9 This is a schematic diagram of the linear motion mechanism in an embodiment of the present invention; Figure 10 This is a schematic diagram of the structure of the high-pressure movable elbow tube blank processing and positioning fixture used for tube bending positioning in an embodiment of the present invention; Figure 11 This is a right view of the positioning fixture for processing high-pressure movable elbow tube blanks in an embodiment of the present invention; Figure 12 This is a schematic diagram of another angle of the structure when using a high-pressure movable elbow tube blank processing and positioning fixture for tube bending positioning in an embodiment of the present invention; Figure 13 This is a schematic diagram of the tube blank after it has been bent under the combined action of the pushing mechanism and the bending die mechanism in an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached drawings: 1. Positioning seat; 101. Limiting groove; 102. Eccentric shaft; 2. Support seat; 201. V-groove; 3. Support platform; 301. Column hole; 302. Mounting groove; 303. Observation groove; 304. Bolt hole; 305. Indicator line; 4. Circular tray; 401. Scale line; 5. Rotating column; 6. Guide seat; 7. Rotating handle; 8. Dovetail groove; 9. Straight groove; 10. Sliding seat; 11. Dovetail block; 12. Limiting block; 1201. Guide threaded hole; 13. Locking bolt; 14. Locking nut; 15. Connecting shaft; 16. Rotating handle; 17. Lead screw; 18. First internal hex bolt; 19. Second internal hex bolt; 20. Washer; 21. Tube blank; 2101. Thin-walled side; 2102. Thick-walled side; 2103. Small end; 2104. Large end. Detailed Implementation

[0019] The present invention will be further illustrated below with reference to specific embodiments. The purpose of this illustration is solely to provide a better understanding of the invention. Therefore, the examples given do not limit the scope of protection of the present invention.

[0020] like Figure 1This is the shape of the tube blank 21 after bending under the action of the bending die mechanism in the simulation experiment. As can be seen from the figure, the eccentric tube blank 21 without any treatment (the tube blank 21 with eccentric tube processing) will have the problem of the small end 2103 tilting downward and outward from the thick wall side 2102 to the thin wall side 2101 after bending. At the same time, material shortage is prone to occur at the bend corner of the outer wall (thick wall side 2102); for example Figure 2 This is the shape of the tube blank 21 after bending under the combined action of the jacking mechanism and the bending die mechanism in the simulation experiment. The yellow part represents the simulation result, and the gray part represents the standard elbow part model. Figure 2 It is known that material accumulation and excessive wall thickness are prone to occur at the bends of the inner wall (thin-walled side 2101). Therefore, to address this issue, through continuous simulation experiments and in-plant processing experiments, it was found that before the bending and forming process, a chamfering treatment can be performed at the small end 2103 of the tube blank 21, such as... Figure 3 This causes the length of the tube blank 21 from the outer wall to the inner wall to gradually decrease, thus solving the problems of material accumulation at the bend of the thin-walled side 2101 and material shortage at the bend of the thick-walled side 2102 after the tube blank 21 is bent.

[0021] However, since the outer surface of the tube blank 21 is circular and the central hole is eccentric, how to locate the thinnest and thickest parts of the eccentric tube blank 21 and perform corner cutting on the eccentric tube blank 21 has become an urgent problem to be solved by those skilled in the art.

[0022] like Figures 4 to 11 As shown in the figure, this embodiment provides a positioning fixture for processing high-pressure movable elbow tube blanks, including a rotating mechanism for controlling the included angle between the tube blank 21 and the saw blade; a linear motion mechanism, mounted on the rotating mechanism, for controlling the axial displacement of the tube blank 21 relative to the saw blade on the sawing machine; and a positioning mechanism, mounted on the linear motion mechanism, for positioning the tube blank 21 at its thinnest and thickest positions.

[0023] The method for positioning high-pressure movable elbow tube blanks using a high-pressure movable elbow tube blank machining positioning fixture includes: first, installing the high-pressure movable elbow tube blank 21 machining positioning fixture on a machine tool; then, installing the tube blank 21 on a positioning mechanism, whereby the positioning mechanism limits the tube blank 21; then, adjusting the rotation mechanism to adjust the included angle between the tube blank 21 and the saw blade to a preset angle; and finally, adjusting the linear motion mechanism to slide the tube blank 21 to the underside of the saw blade for corner cutting.

[0024] like Figure 4 , Figures 10 to 12As shown, the positioning mechanism specifically includes a positioning seat 1 and a support seat 2 spaced apart along the linear motion direction. The support seat 2 is machined with a V-shaped groove 201 for supporting the tube blank 21. The positioning seat 1 is machined with a limiting groove 101 on the side near the support seat 2, which is adapted to the large end 2104 of the tube blank 21. An eccentric shaft 102 adapted to the eccentric hole of the tube blank 21 is provided in the limiting groove 101. The eccentric shaft 102 and the limiting groove 101 are eccentrically arranged in the horizontal direction.

[0025] Insert the large end 2104 of the tube blank 21 into the limiting groove 101. At this time, it is constrained by the eccentric shaft 102, as follows: Figure 12 The thickest side of the tube blank 21 is located on the far left, and the thinnest side of the tube blank 21 is located on the far right. The thickest and thinnest sides are on the same horizontal line. When sawing at an angle, install this fixture on the machine tool and the saw blade can work vertically downwards. There is no need to adjust the saw blade angle. It is ready to use immediately and is simple and convenient.

[0026] like Figures 5 to 8 As shown, the rotating mechanism includes a support platform 3, on which a rotating seat and a locking element for locking the rotating seat are provided. A guide seat 6 is provided on the rotating seat, and a rotating handle 7 is provided on one side of the guide seat 6. A linear motion mechanism is slidably connected to the guide seat 6.

[0027] The rotating base includes a circular tray 4, on which a rotating column 5 is mounted. A guide seat 6 is mounted on the rotating column 5. The guide seat 6 is rectangular in top view. The cross-sectional dimensions of both the guide seat 6 and the circular tray 4 are larger than the cross-sectional dimensions of the rotating column 5. A column hole 301 is provided on the support platform 3 corresponding to the rotating column 5. An installation groove 302 is provided on the bottom surface of the support platform 3 on the outside of the column hole 301 corresponding to the circular tray 4. The locking element is a locking bolt 13. Bolt holes 304 are provided on the left and right sides of the column hole 301 on the support platform 3. 3. Installed in bolt hole 304, penetrating the support 3, the bolt head of locking bolt 13 is located on the lower side, and locking nut 14 is threaded onto the bolt shank of locking bolt 13, located on the upper side of support 3; the end of bolt shank of locking bolt 13 abuts against the bottom surface of guide seat 6, and when circular tray 4 is tightly against the top surface of mounting groove 302, the angle of rotating seat is locked; after loosening locking bolt 13, a gap appears between the end of bolt shank and the bottom surface of guide seat 6, and the angle can be adjusted by rotating guide seat 6 by holding rotating handle 7. For example, Figure 8 As shown, the circular tray 4 and the rotating column 5 are connected and fixed by the first internal hex bolt 18, that is, the circular tray 4 and the rotating column 5 are separate structures. During installation, the circular tray 4 is first installed from the lower side of the support platform 3 into the mounting groove 302, and the rotating column 5 is installed from the upper side of the support platform 3 into the column hole 301. Then the circular tray 4 and the rotating column 5 are connected and fixed, which facilitates assembly and connection. The rotating column 5 can be rotatably connected to the column hole 5 through a slewing bearing, or it can be installed in the column hole 5 through a clearance fit.

[0028] To facilitate observation of the rotation angle, such as Figure 5 , Figure 6 As shown, an observation slot 303 is provided on the side of the support platform 3, and the observation slot 303 is connected to the installation slot 302. A scale line 401 is provided on the side of the circular tray 4, and an indicator line 305 is provided on the side of the support platform 3 above the observation slot 303. When the guide seat 6 is rotated, the scale indicated by the observation indicator line 305 is provided, which makes it easy for the staff to make precise angle adjustments.

[0029] like Figures 9 to 11 As shown, the linear motion mechanism includes a horizontally arranged sliding seat 10. The sliding seat 10 is rectangular in top view. Two dovetail blocks 11 are spaced apart on the bottom surface of the sliding seat 10, with the dovetail blocks 11 arranged along the length of the sliding seat 10. A dovetail groove 8 is formed on the guide seat 6 corresponding to the dovetail blocks 11. The sliding seat 10 is slidably connected to the guide seat 6 via the dovetail blocks 11 and the dovetail groove 8. A shim 20 is installed between the right dovetail block 11 and the dovetail groove 8. An adjusting pin is also provided on the right dovetail block 11. After long-term use, when the shim 20 wears down, tightening the adjusting pin reduces the gap between the shim 20 and the dovetail groove 8, preventing loosening of the sliding connection and ensuring smooth linear motion. If wobbling occurs, the shim 20 can be replaced when it is severely worn. A vertical baffle is provided on the left side of the sliding seat 10. A shaft hole is opened at the lower part of the vertical baffle. A connecting shaft 15 is rotatably connected to the shaft hole through a bearing. A rotating handle 16 is provided on the left side of the connecting shaft 15, and a lead screw 17 is provided on the right side. The lead screw 17 is located on the lower side of the sliding seat 10 and between two dovetail blocks 11. A straight groove 9 for accommodating the lead screw 17 is also opened on the guide seat 6. The straight groove 9 is located in the middle of the dovetail groove 8. A limit block 12 is fixed in the straight groove 9. A guide threaded hole 1201 is provided on the limit block 12. The lead screw 17 is threadedly connected to the limit block 12 through the guide threaded hole 1201.

[0030] like Figure 8 The rotating column 5 and the guide seat 6 are an integral structure. The rotating column 5 and the guide seat 6 are provided with through holes, which pass through the bottom surface of the rotating seat and the straight groove 9. The limiting block 12 and the guide seat 6 are connected and fixed by the second internal hex bolt 19.

[0031] like Figure 10 , Figure 12 As shown, this fixture enables rapid clamping of tube blanks with eccentric holes. The positioning seat 1 and support seat 2 limit the thinnest and thickest positions of the eccentric tube blank 21. A linear motion mechanism facilitates adjustment of the distance between the eccentric tube blank 21 and the saw blade, while a rotation mechanism facilitates adjustment of the angle between them. Operation is simple and convenient, and the clamping is robust and secure. Combined with machine tool processing, it can quickly achieve corner cutting of movable bending tube blanks; for example... Figure 3 This is a schematic diagram of the structure of a flexible bend blank after the chamfering process, as shown below. Figure 13 After the corners are cut, the tube blank 21 is bent by the combined action of the push mechanism and the bending die mechanism, resulting in a flatter end and more uniform wall thickness at the bend, which improves the processing quality and shortens the subsequent finishing processing time.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. All equivalent changes made based on the description and drawings of the present invention are included within the scope of the present invention.

Claims

1. A positioning fixture for machining high-pressure movable elbow pipe blanks, characterized in that: Includes a rotating mechanism for controlling the angle between the tube blank (21) and the saw blade; A linear motion mechanism, mounted on a rotary mechanism, is used to control the axial displacement of the tube blank (21) relative to the saw blade on the sawing machine; The positioning mechanism is installed on the linear motion mechanism and is used to position the tube blank (21) at the thinnest and thickest positions. The positioning mechanism includes a positioning seat (1) and a support seat (2) spaced apart along the linear motion direction. The support seat (2) is machined with a V-groove (201) for supporting the tube blank (21). The positioning seat (1) is machined with a limiting groove (101) that is adapted to the large end (2104) of the tube blank (21) on the side near the support seat (2). An eccentric shaft (102) adapted to the eccentric hole of the tube blank (21) is provided in the limiting groove (101). The eccentric shaft (102) and the limiting groove (101) are eccentrically arranged in the horizontal direction; The rotating mechanism includes a support platform (3), on which a rotating seat and a locking element for locking the rotating seat are provided. A guide seat (6) is provided on the rotating seat, and a rotating handle (7) is provided on one side of the guide seat (6). The linear motion mechanism is slidably connected to the guide seat (6). The rotating seat includes a circular tray (4), a rotating column (5) is provided on the circular tray (4), and a guide seat (6) is provided on the rotating column (5). The cross-sectional dimensions of the guide seat (6) and the circular tray (4) are both larger than the cross-sectional dimensions of the rotating column (5). The support platform (3) is provided with a column hole (301) corresponding to the rotating column (5), and the bottom surface of the support platform (3) is provided with an installation groove (302) corresponding to the circular tray (4) outside the column hole (301). The locking component is a locking bolt (13). Bolt holes (304) are provided on the left and right sides of the column hole (301) on the support (3). The locking bolt (13) is installed in the bolt hole (304) and passes through the support (3). The bolt head of the locking bolt (13) is located on the lower side. When the bolt end of the locking bolt (13) abuts against the bottom surface of the guide seat (6) and the circular tray (4) is pressed against the top surface of the mounting groove (302), the angle of the rotating seat is locked.

2. The high-pressure movable elbow pipe blank machining and positioning fixture according to claim 1, characterized in that: The side of the support (3) is provided with an observation slot (303), which is connected to the installation slot (302). The side of the circular tray (4) is provided with a scale line (401), and the side of the support (3) is provided with an indicator line (305) above the observation slot (303).

3. The high-pressure movable elbow pipe blank processing and positioning fixture according to claim 1, characterized in that: The circular tray (4) and the rotating column (5) are connected and fixed by the first internal hex bolt (18).

4. The high-pressure movable elbow pipe blank machining and positioning fixture according to claim 1, characterized in that: The linear motion mechanism includes a horizontally arranged sliding seat (10), with two dovetail blocks (11) spaced apart on the bottom surface of the sliding seat (10). A dovetail groove (8) is provided on the guide seat (6) corresponding to the dovetail blocks (11). The sliding seat (10) is slidably connected to the guide seat (6) through the dovetail blocks (11) and the dovetail groove (8). A vertical baffle is provided on the left side of the sliding seat (10), and a shaft hole is provided at the lower part of the vertical baffle. A connecting shaft (15) is rotatably connected to the shaft hole through a bearing. The connecting shaft (15) is on the left side. A rotating handle (16) is provided on the side, and a lead screw (17) is provided on the right side. The lead screw (17) is located on the lower side of the sliding seat (10) and between the two dovetail blocks (11). A straight groove (9) is also provided on the guide seat (6). The straight groove (9) is located in the middle of the dovetail groove (8). A limit block (12) is fixed in the straight groove (9). A guide thread hole (1201) is provided on the limit block (12). The lead screw (17) is threadedly connected to the limit block (12) through the guide thread hole (1201).

5. The high-pressure movable elbow pipe blank machining and positioning fixture according to claim 4, characterized in that: The rotating column (5) and the guide seat (6) are an integral structure. The rotating column (5) and the guide seat (6) are provided with through holes. The through holes pass through the bottom surface of the rotating seat and the straight groove (9). The limiting block (12) and the guide seat (6) are connected and fixed by the second internal hex bolt (19).

6. A positioning method for a positioning fixture for machining high-pressure movable elbow pipe blanks according to claim 1, characterized in that, include: First, install the high-pressure movable elbow tube blank processing positioning fixture on the machine tool, then install the tube blank (21) on the positioning mechanism, the positioning mechanism limits the tube blank (21), then adjust the rotation mechanism to adjust the included angle between the tube blank (21) and the saw blade to the preset angle, and finally adjust the linear motion mechanism to slide the tube blank (21) to the underside of the saw blade for corner cutting.

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