An internal support device for longitudinal seam friction stir welding and its welding method

Abstract

The present invention discloses an inner support device for longitudinal seam friction stir welding and its welding method, belonging to the technical field of friction stir welding. The inner support device includes a main support frame and a power drive assembly. A plurality of telescopic assemblies are evenly distributed and movably connected to the outer side of the main support frame. The power drive assembly is coaxially arranged in the main support frame and is movably connected to the main support frame and a plurality of telescopic assemblies through a rocker arm assembly. The power drive assembly drives the plurality of telescopic assemblies to synchronously extend outwards or synchronously contract inwards through the rocker arm assembly. The power drive assembly drives the plurality of telescopic assemblies to synchronously extend outwards through the rocker arm assembly, automatically centering and forming support for the parts to be welded; or the power drive assembly drives the plurality of telescopic assemblies to synchronously contract inwards through the rocker arm assembly to release the parts that have completed longitudinal seam welding. The process of installing and disassembling the inner support device for the parts to be welded is simple, and the installation and disassembly efficiency is high.

Description

Technical Field

[0001] The present invention relates to an internal support device for longitudinal seam friction stir welding and a welding method thereof, belonging to the technical field of friction stir welding. Background Art

[0002] Friction stir welding is a high-quality, efficient, green, low-cost and low-deformation solid-phase welding method, which completely solves a series of problems brought by fusion welding of various non-ferrous metals, and gradually replaces the fusion welding method, and has been widely used in the aerospace field.

[0003] For example, the Chinese patent document with the publication number CN107662044A discloses a special tooling for automatic longitudinal seam friction stir welding of a cylinder. The use process of this special tooling is as follows: First, place the cylinder workpiece on the guide rail, align the cylinder workpiece with the centering guide plate, use the gearbox inside the headstock as the power head, and the front guide wheel and the rear guide wheel perform auxiliary movements. The internal support device is driven into the cylinder workpiece through the gear rack. After the internal support device reaches the cylinder workpiece, the gear rack device of the headstock is locked to prevent the internal support device from moving left and right; then the motor and the elevator in the internal support device drive the lead screw to move upward, and the rear guide wheel moves upward as the lead screw moves upward until the bottom of the upper support and the sliding mechanism fits against the inner side of the cylinder workpiece, and the external external clamping hydraulic device presses the cylinder workpiece, plus the gravity of the internal support device itself to fix the cylinder workpiece. On the basis of the original external clamping tooling for the cylinder, an automatic internal support device is added, and the internal support device uses a precise horizontal pushing mechanism for weld positioning and assembly.

[0004] However, the installation and disassembly process of the internal support device for fixing the cylinder is relatively cumbersome, and the installation and disassembly efficiency is low. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides an internal support device for longitudinal seam friction stir welding and a welding method thereof.

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

[0007] An internal support device for longitudinal seam friction stir welding includes a main support frame and a power drive assembly. A plurality of telescopic assemblies are evenly distributed and movably connected to the outside of the main support frame. The power drive assembly is coaxially arranged inside the main support frame and is movably connected to the main support frame and a plurality of telescopic assemblies through a rocker arm assembly. The power drive assembly drives the plurality of telescopic assemblies to synchronously extend outwards or synchronously contract inwards through the rocker arm assembly.

[0008] The main support frame includes a mandrel and four lower longitudinal beams arranged side by side on the connecting plate. The mandrel is located inside the four lower longitudinal beams and is coaxially arranged with the connecting plate. The connecting lines of the intersections of the four lower longitudinal beams and the connecting plate form a square, and the center of this square coincides with the center of the circle of the connecting plate. Adjacent lower longitudinal beams are connected by a number of diagonal braces, and non-adjacent lower longitudinal beams are connected by a number of intermediate braces.

[0009] The mandrel is a cylinder, and a plurality of mounting holes are evenly arranged on the connecting plate. The number of telescopic assemblies is four, and the four telescopic assemblies are respectively movably connected to the four lower longitudinal beams in the main support frame. The power drive assembly is coaxially arranged inside the mandrel.

[0010] The telescopic assembly includes an upper longitudinal beam and an intermediate connecting beam. A plurality of pin shafts A are arranged side by side on the intermediate connecting beam. The pin shafts A are rotationally connected to the upper longitudinal beam through connecting rod A and rotationally connected to the main support frame through connecting rod B.

[0011] On the side of the upper longitudinal beam far from the intermediate connecting beam, there is a profiling support block. The shape of the side of the profiling support block far from the upper longitudinal beam matches the inner wall shape of the part to be welded.

[0012] The power drive assembly includes an electric cylinder, and the electric cylinder is installed on the main support frame through a mounting seat.

[0013] The rocker arm assembly includes a synchronous drive ring and a number of rocker arms. The synchronous drive ring is arranged on the output shaft of the electric cylinder. One end of the rocker arm is movably connected to the synchronous drive ring through a kidney-shaped hole, and the other end is rotationally connected to the main support frame and the telescopic assembly.

[0014] The inner support device further includes a controller and a pressure sensor. The pressure sensor is arranged on the telescopic assembly, and the controller is electrically connected to the pressure sensor and the power drive assembly.

[0015] A welding method for an inner support device used in longitudinal seam friction stir welding, the welding method includes the following main steps:

[0016] A. Install the inner support device on a device whose output shaft makes a rotary motion;

[0017] B. Use a crane or a hoist to lift the part to be welded onto the inner support device, and the inner support device is located inside the part to be welded;

[0018] C. The power drive assembly drives a number of telescopic assemblies to synchronously extend outwards through the rocker arm assembly, and automatically adjusts the extrusion force of the telescopic assemblies on the inner wall of the part to be welded, so as to form a stable support for the part to be welded, and then remove the crane or the hoist;

[0019] D. Start the device, drive the inner support device to rotate until the longitudinal seam on the part to be welded is aligned with the stirring head in the friction stir welding machine, and then turn off the device;

[0020] E. Perform friction stir welding on the longitudinal seam. After welding is completed, the power drive assembly drives several telescopic assemblies to synchronously contract inward through the rocker arm assembly. At the same time, use a crane or overhead crane to remove the welded parts from the internal support device.

[0021] The method for the power drive assembly to automatically adjust the extrusion force of the telescopic assembly on the inner wall of the part to be welded in step C includes the following main steps:

[0022] a. According to the clamping requirements of the part to be welded, preset the range of the extrusion force of the telescopic assembly on the inner wall of the part to be welded on the controller;

[0023] b. The pressure sensor transmits the extrusion force of the telescopic assembly on the inner wall of the part to be welded to the controller in real time;

[0024] c. The controller compares the detected value of the extrusion force with the preset range. If the extrusion force is too small, the controller drives the output shaft of the electric cylinder to extend or retract a certain distance, so that several telescopic assemblies synchronously expand outward to increase the extrusion force of the telescopic assembly on the inner wall of the part to be welded; if the extrusion force is too large, the controller drives the output shaft of the electric cylinder to retract or extend a certain distance, so that several telescopic assemblies synchronously contract inward to reduce the extrusion force of the telescopic assembly on the inner wall of the part to be welded; if the detected value of the extrusion force is within the preset range, the electric cylinder does not move.

[0025] The beneficial effects of the present invention are as follows:

[0026] 1. The power drive assembly drives several telescopic assemblies to synchronously expand outward through the rocker arm assembly, automatically centering and forming a support for the part to be welded; or the power drive assembly drives several telescopic assemblies to synchronously contract inward through the rocker arm assembly to release the parts that have completed longitudinal seam welding; the process of installing and disassembling the internal support device for the part to be welded is simple, and the installation and disassembly efficiency is high.

[0027] 2. The internal support device can be used to support multiple cylinders with different inner diameters, and can also be used to support multiple square pipes with different cross-sections, with a wide range of applications.

[0028] 3. By using the profiling support block, the contact area between the internal support device and the part to be welded is increased, which helps to improve the support stability of the part to be welded.

[0029] 4. By controlling the extrusion force of the telescopic assembly on the inner wall of the part to be welded through the controller, it is ensured that the internal support device forms a stable support for the part to be welded, avoiding the situation that the part to be welded rotates circumferentially or moves axially during the welding process, and ensuring the quality of longitudinal seam welding.

[0030] 5. By controlling the extrusion force of the telescopic assembly on the inner wall of the part to be welded through the controller, it is possible to avoid damage to the internal support device due to excessive extrusion force. Description of the Drawings

[0031] Figure 1 Schematic diagram of the three-dimensional structure of the present invention;

[0032] Figure 2 Schematic diagram of the right view structure of the present invention;

[0033] Figure 3 Schematic diagram of the front view structure of the present invention;

[0034] Figure 4 Schematic diagram of the assembly structure of the power drive assembly and the rocker arm assembly of the present invention.

[0035] In the figure: 1 - mandrel, 2 - intermediate strut, 3 - lower longitudinal beam, 4 - diagonal strut, 5 - pin shaft A, 6 - power drive assembly, 7 - intermediate connecting beam, 8 - upper longitudinal beam, 9 - profiling support block, 10 - connecting plate, 11 - synchronous drive ring, 12 - rocker arm, 13 - electric cylinder, 14 - mounting seat. Specific embodiments

[0036] The technical solutions of the present invention will be further described below, but the scope of protection is not limited thereto.

[0037] As Figures 1 to 4 shown, an internal support device for longitudinal seam friction stir welding according to the present invention includes a main support frame and a power drive assembly 6. A plurality of telescopic assemblies are evenly distributed and movably connected to the outside of the main support frame. The power drive assembly 6 is coaxially installed in the main support frame and is movably connected to the main support frame and a plurality of telescopic assemblies through a rocker arm assembly. The power drive assembly 6 drives a plurality of telescopic assemblies to synchronously extend outwards or synchronously contract inwards through the rocker arm assembly. When in use, the power drive assembly 6 drives a plurality of telescopic assemblies to synchronously extend outwards through the rocker arm assembly, automatically centering and forming support for the parts to be welded; or the power drive assembly 6 drives a plurality of telescopic assemblies to synchronously contract inwards through the rocker arm assembly to release the parts that have completed longitudinal seam welding. Thus, it can be seen that the process of installing and disassembling the internal support device for the parts to be welded is simple and the installation and disassembly efficiency is high.

[0038] The main support frame includes a mandrel 1 and four lower longitudinal beams 3 welded side by side on a connecting plate 10. The mandrel 1 is located inside the four lower longitudinal beams 3 and is coaxially arranged with the connecting plate 10. The connecting lines of the intersections of the four lower longitudinal beams 3 and the connecting plate 10 form a square, and the center of the square coincides with the center of the circle of the connecting plate 10. Adjacent lower longitudinal beams 3 are connected by a plurality of diagonal struts 4, and non-adjacent lower longitudinal beams 3 are connected by a plurality of intermediate struts 2.

[0039] The mandrel 1 is a cylinder. A plurality of mounting holes are evenly machined on the connecting plate 10. The number of telescopic components is four, and the four telescopic components are respectively movably connected to the four lower longitudinal beams 3 in the main support frame. The power drive component 6 is coaxially installed in the mandrel 1. During use, mounting holes are machined on the connecting plate 10, which facilitates the installation of the connecting plate 10 to the output shaft of the equipment through fasteners. The output shaft of this equipment can perform a rotary motion, thereby driving the inner support device to rotate a certain angle. The inner support device can both automatically center and support a welded part with a circular inner wall, such as a cylinder, and automatically center and support a welded part with a square inner wall, such as a square pipe.

[0040] The telescopic component includes an upper longitudinal beam 8 and an intermediate connecting beam 7. A plurality of pin shafts A5 are arranged side by side on the intermediate connecting beam 7. The pin shaft A5 is rotationally connected to the upper longitudinal beam 8 through a connecting rod A and rotationally connected to the lower longitudinal beam 3 in the main support frame through a connecting rod B. During use, the upper longitudinal beam 8, the intermediate connecting beam 7, and the lower longitudinal beam 3 are parallel, and the upper longitudinal beam 8 and the intermediate connecting beam 7 can perform translational motion relative to the lower longitudinal beam 3, that is, they can extend outwards and contract inwards.

[0041] On one side of the upper longitudinal beam 8 away from the intermediate connecting beam 7, a profiling support block 9 is installed. The shape of the side of the profiling support block 9 away from the upper longitudinal beam 8 matches the shape of the inner wall of the welded part. When the shape of the inner wall of the welded part is square, the shape of the side of the profiling support block 9 away from the upper longitudinal beam 8 is a plane; when the shape of the inner wall of the welded part is circular, the shape of the side of the profiling support block 9 away from the upper longitudinal beam 8 is an arc surface. By means of the profiling support block 9, the contact area between the inner support device and the inner wall of the welded part is increased, which helps to improve the support stability of the welded part.

[0042] The power drive component 6 includes an electric cylinder 13. The electric cylinder 13 is installed in the mandrel 1 of the main support frame through a mounting seat 14. During use, the output shaft of the electric cylinder 13 is coaxial with the mandrel 1.

[0043] The rocker arm assembly includes a synchronous drive ring 11 and a plurality of rocker arms 12. The synchronous drive ring 11 is installed on the output shaft of the electric cylinder 13. One end of the rocker arm 12 is movably connected to the synchronous drive ring 11 through a kidney-shaped hole, and the other end is rotationally connected to the main support frame and the telescopic component. During use, the synchronous drive ring 11 is coaxial with the output shaft of the electric cylinder 13; one end of the rocker arm 12 is movably connected to the synchronous drive ring 11 through a kidney-shaped hole to avoid the rocker arm 12 from getting stuck, and the other end is rotationally connected to the lower longitudinal beam 3 through a pin shaft B and rotationally connected to the intermediate connecting beam 7 through a pin shaft C. The output shaft of the electric cylinder 13 drives all the rocker arms 12 to rotate synchronously around the pin shaft B through the synchronous drive ring 11, so that all the intermediate connecting beams 7 and the upper longitudinal beams 8 extend outwards or contract inwards synchronously.

[0044] The inner support device further includes a controller and a pressure sensor. The pressure sensor is arranged on the telescopic assembly, and the controller is electrically connected to the pressure sensor and the power drive assembly 6.

[0045] A welding method for an inner support device used in longitudinal seam friction stir welding, the welding method including the following main steps:

[0046] A. Install the inner support device on a device whose output shaft makes a rotary motion;

[0047] B. Use a crane or a hoist to lift the part to be welded onto the inner support device, and the inner support device is located inside the part to be welded;

[0048] C. The power drive assembly 6 drives a plurality of telescopic assemblies to synchronously extend outwards through the rocker arm assembly, and automatically adjusts the extrusion force of the telescopic assemblies on the inner wall of the part to be welded, so as to form a stable support for the part to be welded, and then remove the crane or the hoist;

[0049] D. Start the device, drive the inner support device to rotate until the longitudinal seam on the part to be welded is aligned with the stirring head in the friction stir welding machine, and then turn off the device;

[0050] E. Perform friction stir welding on the longitudinal seam. After the welding is completed, the power drive assembly 6 drives a plurality of telescopic assemblies to synchronously contract inwards through the rocker arm assembly, and at the same time, use a crane or a hoist to remove the part that has been welded from the inner support device.

[0051] The method for the power drive assembly 6 to automatically adjust the extrusion force of the telescopic assemblies on the inner wall of the part to be welded in step C includes the following main steps:

[0052] a. According to the clamping requirements of the part to be welded, preset the range of the extrusion force of the telescopic assemblies on the inner wall of the part to be welded on the controller;

[0053] b. The pressure sensor transmits the extrusion force of the telescopic assemblies on the inner wall of the part to be welded to the controller in real time;

[0054] c. The controller compares the detected value of the extrusion force with the preset range. If the extrusion force is too small, the controller drives the output shaft of the electric cylinder 13 to extend or retract a certain distance, so that several telescopic components synchronously expand outwards to increase the extrusion force of the telescopic components on the inner wall of the part to be welded. If the extrusion force is too large, the controller drives the output shaft of the electric cylinder 13 to retract or extend a certain distance, so that several telescopic components synchronously contract inwards to reduce the extrusion force of the telescopic components on the inner wall of the part to be welded. If the detected value of the extrusion force is within the preset range, the electric cylinder 13 does not act. By controlling the extrusion force of the telescopic components on the inner wall of the part to be welded through the controller, it is ensured that the inner support device forms a stable support for the part to be welded, avoiding the situation that the part to be welded rotates circumferentially or moves axially during the welding process, and ensuring the longitudinal seam welding quality. In addition, by controlling the extrusion force of the telescopic components on the inner wall of the part to be welded through the controller, it is possible to avoid damage to the inner support device due to excessive extrusion force.

[0055] The working principle of the inner support device for longitudinal seam friction stir welding of the present invention is as follows:

[0056] The part to be welded is lifted onto the inner support device by a crane or a hoist, and the inner support device is located inside the part to be welded. The electric cylinder 13 is started, and the output shaft of the electric cylinder 13 extends a certain distance, and drives four rocker arms 12 to rotate synchronously around the pin shaft B through the synchronous drive ring 11. Thus, all the intermediate connecting beams 7 and the upper longitudinal beam 8 are driven by the rocker arms 12 to expand outwards synchronously, so that the square support blocks 9 abut against the inner wall of the part to be welded, and automatically center to form a stable support for the part to be welded. After the longitudinal seam welding is completed, the output shaft of the electric cylinder 13 retracts a certain distance, and all the intermediate connecting beams 7 and the upper longitudinal beam 8 are driven by the synchronous drive ring 11 and the rocker arms 12 to contract inwards synchronously, releasing the part that has completed the longitudinal seam welding.

[0057] The inner support device for longitudinal seam friction stir welding and its welding method provided by the present invention have the following beneficial effects:

[0058] 1. The power drive assembly 6 drives several telescopic components to expand outwards synchronously through the rocker arm assembly, automatically centering to form a support for the part to be welded; or the power drive assembly 6 drives several telescopic components to contract inwards synchronously through the rocker arm assembly, releasing the part that has completed the longitudinal seam welding; the process of installing and disassembling the inner support device for the part to be welded is simple, and the installation and disassembly efficiency is high.

[0059] 2. The inner support device can be used to support multiple cylinders with different inner diameters, and can also be used to support multiple square pipes with different cross-sections, with a wide range of applications.

[0060] 3. By using the profiling support block 9, the contact area between the inner support device and the part to be welded is increased, which helps to improve the support stability for the part to be welded.

[0061] 4. Adjust the extrusion force of the telescopic component on the inner wall of the parts to be welded through the controller to ensure that the inner support device forms a stable support for the parts to be welded, avoid the situation that the parts to be welded rotate circumferentially or move axially during the welding process, and ensure the longitudinal weld quality.

[0062] 5. Adjust the extrusion force of the telescopic component on the inner wall of the parts to be welded through the controller, which can avoid damage to the inner support device due to excessive extrusion force.

Claims

1. An internal support device for longitudinal seam friction stir welding, characterized in that: It includes a main support frame and a power drive assembly (6). A number of telescopic assemblies are evenly distributed and movably connected to the outside of the main support frame. The power drive assembly (6) is coaxially arranged inside the main support frame and is movably connected to the main support frame and a number of telescopic assemblies through a rocker arm assembly. The power drive assembly (6) drives a number of telescopic assemblies to synchronously extend outwards or synchronously contract inwards through the rocker arm assembly; The main support frame includes a mandrel (1) and four lower longitudinal beams (3) arranged side by side on a connecting plate (10). The mandrel (1) is located inside the four lower longitudinal beams (3) and is coaxially arranged with the connecting plate (10). The connecting lines of the intersections of the four lower longitudinal beams (3) and the connecting plate (10) form a square, and the center of this square coincides with the center of the circle of the connecting plate (10); A number of diagonal braces (4) are used to connect between adjacent lower longitudinal beams (3), and a number of intermediate braces (2) are used to connect between non-adjacent lower longitudinal beams (3); The number of telescopic assemblies is four, and the four telescopic assemblies are respectively movably connected to the four lower longitudinal beams (3) in the main support frame. The power drive assembly (6) is coaxially arranged inside the mandrel (1); The telescopic assembly includes an upper longitudinal beam (8) and an intermediate connecting beam (7). A number of pin shafts A (5) are arranged side by side on the intermediate connecting beam (7). The pin shaft A (5) is rotationally connected to the upper longitudinal beam (8) through a connecting rod A and rotationally connected to the main support frame through a connecting rod B.

2. The internal support device for longitudinal seam friction stir welding according to claim 1, characterized in that: The mandrel (1) is a cylinder, and a number of mounting holes are evenly arranged on the connecting plate (10).

3. The internal support device for longitudinal seam friction stir welding according to claim 1, characterized in that: On the side of the upper longitudinal beam (8) far from the intermediate connecting beam (7), there is a profiling support block (9). The shape of the side of the profiling support block (9) far from the upper longitudinal beam (8) matches the inner wall shape of the part to be welded.

4. The internal support device for longitudinal seam friction stir welding according to claim 1, characterized in that: The power drive assembly (6) includes an electric cylinder (13), and the electric cylinder (13) is installed on the main support frame through a mounting seat (14).

5. The internal support device for longitudinal seam friction stir welding according to claim 4, characterized in that: The rocker arm assembly includes a synchronous drive ring (11) and a number of rocker arms (12). The synchronous drive ring (11) is arranged on the output shaft of the electric cylinder (13). One end of the rocker arm (12) is movably connected to the synchronous drive ring (11) through a waist-shaped hole, and the other end is rotationally connected to the main support frame and the telescopic assembly.

6. The internal support device for longitudinal seam friction stir welding according to any one of claims 1 to 5, characterized in that: The internal support device further includes a controller and a pressure sensor. The pressure sensor is arranged on the telescopic assembly, and the controller is electrically connected to the pressure sensor and the power drive assembly (6).

7. A welding method for the internal support device for longitudinal seam friction stir welding according to any one of claims 1 to 6, characterized in that: The welding method includes the following steps: A. Install the inner support device on the equipment where the output shaft makes a rotary motion; B. Use a crane or hoist to lift the parts to be welded onto the inner support device, and the inner support device is located inside the parts to be welded; C. The power drive assembly (6) drives several telescopic assemblies to extend outward synchronously through the rocker arm assembly, and automatically adjusts the extrusion force of the telescopic assemblies on the inner wall of the parts to be welded, so as to form a stable support for the parts to be welded, and then remove the crane or hoist; D. Start the equipment and drive the inner support device to rotate until the longitudinal seam on the parts to be welded is aligned with the stirring head in the friction stir welding machine, and then turn off the equipment; E. Perform friction stir welding on the longitudinal seam. After welding is completed, the power drive assembly (6) drives several telescopic assemblies to contract inward synchronously through the rocker arm assembly, and at the same time, use a crane or hoist to remove the welded parts from the inner support device.

8. The welding method of the inner support device for longitudinal seam friction stir welding according to claim 7, characterized in that: The method for the power drive assembly (6) in step C to automatically adjust the extrusion force of the telescopic assemblies on the inner wall of the parts to be welded mainly includes the following steps: a. According to the clamping requirements of the parts to be welded, preset the range of the extrusion force of the telescopic assemblies on the inner wall of the parts to be welded on the controller; b. The pressure sensor transmits the extrusion force of the telescopic assemblies on the inner wall of the parts to be welded to the controller in real time; c. The controller compares the detected value of the extrusion force with the preset range. If the extrusion force is too small, the controller drives the output shaft of the electric cylinder (13) to extend or retract a certain distance, so that several telescopic assemblies extend outward synchronously to increase the extrusion force of the telescopic assemblies on the inner wall of the parts to be welded; if the extrusion force is too large, the controller drives the output shaft of the electric cylinder (13) to retract or extend a certain distance, so that several telescopic assemblies contract inward synchronously to reduce the extrusion force of the telescopic assemblies on the inner wall of the parts to be welded; if the detected value of the extrusion force is within the preset range, the electric cylinder (13) does not move.

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