A method for precisely clamping a workpiece for inertia friction welding

Abstract

The application provides a method for accurately clamping workpieces for inertia friction welding, which is suitable for clamping shaft / pipe workpieces, adopts a welding clamping tool (10) and a feeding clamp tool (20), the welding clamping tool (10) comprises a tool body (11), a clamping jaw (12) and a top rod (13), the feeding clamp tool (20) comprises a tool seat (21), a chuck connecting seat (22), a sliding rod (23), a spring (24) and a chuck assembly, and the two adjacent sides of the chuck connecting seat (22) are respectively provided with a first chuck assembly (250) and a second chuck assembly (260) through the assemblies formed by the sliding rod (23) and the spring (24). The method can accurately position and stably clamp the workpieces when the workpieces are fed, ensures coaxiality, and effectively avoids the problems of inaccurate position, out-of-limit position and poor coaxiality caused by the fact that the robot mechanical arm only moves to a position point to feed.

Description

Technical Field

[0001] This invention relates to the field of solid-state metal welding technology, and more specifically to a method for precisely clamping workpieces for inertial friction welding. Background Technology

[0002] Radial inertial friction welding is one of the effective methods to achieve high-strength connections of dissimilar metal ring composite components such as aluminum-steel, aluminum-titanium, and low-carbon steel-high-strength alloy steel. It has the advantages of lightweight, high strength, and low cost, and is widely used in weaponry, aerospace, vehicles, ships and other fields.

[0003] Existing radial inertial friction welding uses robots to automatically load and unload workpieces, reducing labor costs while increasing the safety and efficiency of the welding production process. When using robots for loading and unloading, the workpiece to be welded is usually gripped by a gripper at the end of the robot arm, and then the robot moves to the appropriate position according to the spatial position point set by the robot program and puts the workpiece to be welded in, thus realizing the loading of the workpiece to be welded. However, the robots equipped with existing radial inertial friction welding machines place the workpiece in the welding position using only the spatial position points set by the robot itself. This results in inaccurate placement of the workpiece and inadequate positioning (i.e., only ensuring that the workpiece is placed in the spindle gripping area and that the spindle jaws can firmly hold it). After the welding machine pre-clamps, the entire workpiece forms a cantilever structure (i.e., a cantilever structure with the spindle jaw gripping end as the fulcrum). This causes an increase in torque on the welding clamping fixture during the welding process when welding pressure is applied, reducing the life of the welding clamping fixture. At the same time, the cantilever structure also causes radial runout of the workpiece as it rotates with the flywheel during the welding process, thus affecting the welding quality. Furthermore, when the robot equipped with the existing radial inertial friction welding machine places the workpiece to be welded, it cannot ensure the coaxiality between the workpiece and the welding machine spindle. In other words, the difference in coaxiality between the workpiece and the welding machine spindle can easily cause uneven force on the workpiece during the welding process and slippage, which can lead to a serious reduction in the welding quality of the workpiece or even failure to weld, thus reducing welding efficiency and increasing the waste of raw materials. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide a method for precisely clamping workpieces for inertial friction welding. This method can accurately position and securely clamp the workpiece during loading, while ensuring the coaxiality between the workpiece and the welding machine spindle. This effectively avoids problems such as inaccurate positioning, inadequate positioning, and poor coaxiality caused by the robotic arm simply moving to a position point for loading, thereby improving welding quality, increasing the life of welding fixtures, and improving welding efficiency.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A method for precisely clamping workpieces for inertial friction welding, applicable to the clamping of shaft / tube workpieces, is characterized by: employing a welding clamping fixture and a loading fixture. The welding clamping fixture includes a fixture body, clamping jaws, and a push rod. The loading fixture includes a fixture base, a chuck connecting seat, a slide rod, a spring, and a chuck assembly. The fixture base is connected to the end of a robot arm, and a chuck connecting seat is provided inside the fixture base. A first chuck assembly and a second chuck assembly are respectively provided on two adjacent sides of the chuck connecting seat through assemblies formed by the slide rod and the spring. The first chuck assembly and the second chuck assembly are respectively used to clamp shaft-type workpieces to be welded and tube-type workpieces to be welded.

[0007] The precise workpiece clamping method includes: a) installation of welding clamping fixture; b) pretreatment of the workpiece to be welded; c) clamping of the workpiece to be welded by the loading fixture; d) clamping of the workpiece to be welded into the welding clamping fixture; e) internal lifting of the workpiece to be welded; f) pre-clamping of the clamping jaws; g) releasing of the workpiece by the loading fixture.

[0008] For further optimization, the welding clamping fixture is installed on the spindle of the friction welding machine. The end of the fixture body away from the friction welding machine is provided with a clamping hole and a top rod is provided at the bottom of the clamping hole. The inner wall of the end of the clamping hole away from the spindle of the friction welding machine is evenly provided with clamping claws.

[0009] For further optimization, the push rod is a tapered structure with a diameter that gradually decreases from the direction of approaching the friction welding machine to the direction of away from the friction welding machine, and multiple snap-fit ​​ribs are evenly arranged on the outer wall of the push rod.

[0010] Preferably, multiple first protruding ridges are evenly arranged on the side of the clamping claw near the central axis of the tooling body to increase friction and avoid damage to the workpiece to be welded during the clamping process.

[0011] For further optimization, the tooling base has an inverted "C" shaped cross-section, and the chuck connecting seat is located inside the tooling base and is rotatably connected to the tooling base through a rotating shaft.

[0012] For further optimization, one end of the slide rod is slidably connected to the chuck connecting seat, and the other end is fixedly connected to the chuck assembly (i.e., the first chuck assembly or the second chuck assembly). A spring is provided on the outer wall of the slide rod, and both ends of the spring are respectively connected to the chuck assembly (i.e., the first chuck assembly or the second chuck assembly) and the chuck connecting seat.

[0013] Preferably, there are 2 to 5 sliding rods and 2 to 5 corresponding springs, and the sliding rods are evenly arranged around the axis of the clamp assembly.

[0014] Preferably, a limiting ring is provided on the outer wall of the slide rod to hard limit the compression of the spring.

[0015] For further optimization, the chuck assembly (i.e., the first chuck assembly or the second chuck assembly) includes a connecting plate, a driving cavity, and a chuck. The connecting plate is fixedly connected to the end of the slide rod away from the chuck connecting seat, and the driving cavity is provided on the side of the connecting plate away from the slide rod. The chuck is provided on the side of the driving cavity away from the connecting plate. The inner wall of the first chuck of the first chuck assembly away from the driving cavity has an inner groove, and the end face of the inner groove has multiple second protruding ridges. The outer wall of the second chuck of the second chuck assembly away from the driving cavity has an outer groove, and the end face of the outer groove has multiple third protruding ridges.

[0016] Preferably, the inner groove surface is configured as a concave arc-shaped structure to match the outer wall of shaft-type workpieces, and the outer groove surface is configured as a convex arc-shaped structure to match the inner wall of tubular workpieces.

[0017] To further optimize the process, the precise workpiece clamping method is specifically as follows:

[0018] a. Installation of welding clamping fixture: Install the welding clamping fixture on the rotating spindle of the friction welding machine and ensure that the welding clamping fixture and the rotating spindle of the friction welding machine are coaxial;

[0019] b. Pre-treatment of workpieces to be welded:

[0020] For shaft-type workpieces: A circular groove is machined on the end face of the shaft-type workpiece closest to the friction welding machine according to the diameter of the push rod, and a first snap-fit ​​groove is machined on the outer wall of the circular groove corresponding to the snap-fit ​​rib on the outer wall of the push rod.

[0021] For tubular workpieces: A second snap-fit ​​groove is machined on the end face of the tubular workpiece near the friction welding machine to correspond to the snap-fit ​​rib on the outer wall of the push rod;

[0022] c. The loading fixture is used to clamp the workpiece to be welded:

[0023] For shaft-type workpieces: the first chuck of the first chuck assembly clamps the outer wall of the shaft-type workpiece and ensures that the inner groove sidewall (i.e., the inner wall on the side near the chuck connecting seat) abuts against the end face of the shaft-type workpiece away from the friction welding machine.

[0024] For tubular workpieces: The second chuck of the second chuck assembly clamps the inner wall of the tubular workpiece and ensures that the outer groove sidewall (i.e., the inner wall near the chuck connecting seat) presses against the tubular workpiece;

[0025] d. The workpiece to be welded is clamped into the welding clamping fixture: The robot arm moves to the preset end position and places the end of the workpiece away from the loading fixture into the clamping hole. At this time, the end face of the workpiece to be welded does not contact the push rod, and the axis of the workpiece to be welded is initially positioned with the axis of the friction welding machine spindle.

[0026] e. Internal positioning of the workpiece to be welded: After the robot arm initially positions the workpiece to be welded, it controls the workpiece to be welded to move along the main axis of the friction welding machine. The end of the workpiece to be welded that is close to the friction welding machine gradually contacts the push rod. During the translation, the workpiece to be welded is finely adjusted in real time to ensure that the push rod is fully engaged in the circular groove of the shaft workpiece or the inner hole of the tube workpiece, and the locking rib is engaged in the first locking groove or the second locking groove. Continue to translate until the slide bar slides and the spring is compressed to the preset pressure, then stop the movement of the robot arm.

[0027] f. Clamping jaws pre-clamping: Activate the clamping jaws to clamp the outer wall of shaft or tube workpieces;

[0028] g. The loading clamping fixture releases the workpiece and returns it to its initial position, and then the friction welding process is carried out.

[0029] For further optimization, the diameter of the shaft-type workpiece is φ20~50mm; the inner diameter of the tube-type workpiece is φ28~62mm.

[0030] For further optimization, the preset pressure of the spring in step e is 0.1 to 0.7 MPa.

[0031] The present invention has the following technical effects:

[0032] This application utilizes the cooperation between a welding clamping fixture and a feeding fixture. Through the placement of a push rod and a locking rib, along with a circular groove and a locking slot, the workpiece to be welded is tightly pressed against the end face of the push rod of the welding clamping fixture. This ensures good coaxiality between the workpiece, the welding clamping fixture, and the welding machine spindle. The coaxiality using this method is ≤10 microns. Simultaneously, the push rod and locking rib position the end of the workpiece to be welded, forming a fulcrum. Combined with the clamping jaws, this dual positioning effectively prevents the workpiece from forming a cantilever structure, thus avoiding radial runout or increased torque during welding. Furthermore, the cooperation of the locking ribs and locking slots effectively prevents slippage between the clamping jaws and the workpiece during friction welding, ensuring welding quality and efficiency while avoiding material waste. This application achieves a 20% improvement in welding efficiency compared to existing technologies while maintaining welding quality. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure for precisely clamping shaft-type workpieces in an embodiment of the present invention.

[0034] Figure 2 for Figure 1 A magnified view of part A in the image.

[0035] Figure 3 for Figure 1A magnified view of part B in the image.

[0036] Figure 4 This is a schematic diagram of the structure for precisely clamping tubular workpieces in an embodiment of the present invention.

[0037] Figure 5 for Figure 4 A magnified view of part C.

[0038] Among them, 100 is a friction welding machine; 200 is a workpiece to be welded; 10 is a welding clamping fixture; 11 is a fixture body; 110 is a clamping hole; 12 is a clamping claw; 13 is a push rod; 130 is a snap-fit ​​rib; 20 is a feeding fixture; 21 is a fixture base; 210 is a rotating shaft; 22 is a chuck connecting seat; 23 is a slide rod; 230 is a limiting ring; 24 is a spring; 250 is a first chuck assembly; 251 is a connecting plate; 252 is a drive cavity; 253 is a first chuck; 2530 is an inner groove; 260 is a second chuck assembly; 261 is a second chuck; 2610 is an inner groove. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1:

[0041] For shaft-type workpieces to be welded, such as steel shafts with a diameter of φ20~50mm, Figures 1-3 As shown, a method for precisely clamping workpieces for inertial friction welding is characterized by employing a welding clamping fixture 10 and a feeding fixture 20. The welding clamping fixture 10 is mounted on the spindle of a friction welding machine 100 and includes a fixture body 11, clamping jaws 12, and a push rod 13. A clamping hole 110 is provided at one end of the fixture body 11 away from the friction welding machine 100, and a push rod 13 is provided at the bottom of the clamping hole 110 (e.g., ...). Figure 1As shown: the clamping hole 110 and the push rod 13 are coaxial with the tooling body 11 and the main shaft of the friction welding machine 100. The inner wall of the clamping hole 110 away from the main shaft of the friction welding machine 100 and the clamping claws 12 are evenly arranged around the axis of the tooling body 11 (the clamping claws 12 are set according to the actual situation and can be controlled by a pneumatic drive device). The push rod 13 is a tapered structure with a diameter that gradually decreases from the direction close to the friction welding machine 100 to the direction away from the friction welding machine 100. The outer wall of the push rod 13 (around its axis) is evenly provided with multiple snap-fit ​​ribs 130. The number of snap-fit ​​ribs 130 is determined according to the actual situation, preferably 5 to 8. The side of the clamping claws 12 near the central axis of the tooling body 11 is evenly provided with multiple first protruding ridges to increase the friction force and avoid damage to the workpiece 200 to be welded during the clamping process.

[0042] The loading fixture 20 includes a fixture base 21, a chuck connecting seat 22, a slide bar 23, a spring 24, and a chuck assembly. The fixture base 21 is connected to the end effector of the robot arm, and the chuck connecting seat 22 is installed inside the fixture base 21. Specifically, the cross-section of the fixture base 21 is an inverted "C" shape (e.g., Figure 1 As shown, the chuck connecting seat 22 is disposed inside the tooling seat 21 and is rotatably connected to the tooling seat 21 via a rotating shaft 210. Two adjacent sides of the chuck connecting seat 22 are respectively equipped with a first chuck assembly 250 and a second chuck assembly 260 formed by a slide rod 23 and a spring 24. In this embodiment, the first chuck assembly 250 is used to clamp the shaft-type workpiece 200 to be welded. One end of the slide rod 23 is slidably connected to the chuck connecting seat 22, and the other end is fixedly connected to the first chuck assembly 250. A spring 24 is provided on the outer wall of the slide rod 23, and both ends of the spring 24 are respectively connected to the first chuck assembly 250 and the chuck connecting seat 22. There are 2 to 5 slide rods 23 (preferably 3), and the corresponding springs 24 are also 2 to 5 (preferably 3), and the slide rods 23 are evenly arranged around the axis of the first chuck assembly 250. A limiting ring 230 is provided on the outer wall of the slide rod 23 to hard limit the compression of the spring 24.

[0043] The first chuck assembly 250 includes a connecting plate 251, a driving cavity 252, and a first chuck 253. The connecting plate 251 is fixedly connected to the end of the slide bar 23 away from the chuck connecting seat 22, and the driving cavity 252 is provided on the side of the connecting plate 251 away from the slide bar 23 (the driving cavity 252 is provided with a driving mechanism for driving the first chuck 253 to clamp shaft-type workpieces, and the clamping of the first chuck 253 can be achieved by a pneumatic mechanism). The first chuck 253 is provided on the side of the driving cavity 252 away from the connecting plate 251 (uniformly around the axis of the connecting plate 251). The number of first chucks 253 is 2 to 5. In this embodiment, two first chucks 253 are used. The inner wall of the end of the first chuck 253 away from the driving cavity 252 has an inner groove 2530, and the end face of the inner groove 2530 is provided with multiple second protruding ridges. The groove surface of the inner groove 2530 is set as a concave arc-shaped structure to match the outer wall of the shaft-type workpiece.

[0044] The specific method for precise workpiece clamping is as follows:

[0045] a. Installation of welding clamping fixture: Install the welding clamping fixture 10 on the rotating spindle of the friction welding machine 100 and ensure that the welding clamping fixture 10 and the rotating spindle of the friction welding machine 100 are coaxial.

[0046] b. Pre-treatment of workpieces to be welded:

[0047] A circular groove is machined on the end face of the shaft workpiece near the friction welding machine 100 according to the diameter of the push rod 13, and a first snap-fit ​​groove is machined on the outer wall of the circular groove corresponding to the snap-fit ​​rib 130 on the outer wall of the push rod 13.

[0048] c. The loading fixture is used to clamp the workpiece to be welded:

[0049] The first chuck 253 clamps the outer wall of the shaft-like workpiece and ensures that the side wall of the inner groove 2530 (i.e., the inner wall near the chuck connecting seat 22) abuts against the end face of the shaft-like workpiece away from the friction welding machine 100 (e.g., ...). Figure 1 As shown); a pressure sensor can be installed on the first chuck 253 to detect the pressure during the clamping process. When the pressure reaches 0.1 to 0.7 MPa, the pressure sensor feeds back a signal, and the robot control system operates; the length of the first chuck 253 is 20 to 50 mm (preferably 30 mm); the groove depth of the inner groove 2530 is 5 to 8 mm (preferably 6.5 mm);

[0050] d. The workpiece to be welded is clamped into the welding clamping fixture: The robot arm moves to the preset position of the end of the robot arm and puts the end of the workpiece to be welded away from the loading fixture 20 into the clamping hole 110 (this step can be done using existing conventional control methods, which can be understood by those skilled in the art). At this time, the end face of the workpiece to be welded 200 does not contact the push rod 13, and the axis of the workpiece to be welded 20 is initially positioned with the axis of the main shaft of the friction welding machine 100.

[0051] e. Internal positioning of the workpiece to be welded: After the robot arm initially positions the workpiece 200 to be welded, the workpiece 200 is moved along the main axis of the friction welding machine 100 by the robot arm. The end of the workpiece 200 close to the friction welding machine 100 gradually contacts the push rod 13. During the translation, the workpiece is finely adjusted in real time to ensure that the push rod 13 is fully engaged in the circular groove of the shaft workpiece and the locking rib 130 is engaged in the first locking groove (during the movement, the welding clamping fixture 10 can be slowly rotated to ensure that the locking rib 130 is engaged in the first locking groove, and then the robot arm is finely adjusted so that the push rod 13 is fully engaged in the circular groove). Continue to translate until the slide rod 23 slides and the spring 24 is compressed to the preset pressure (which can be monitored by setting a pressure sensor), then stop the movement of the robot arm; the preset pressure is 0.1 to 0.7 MPa.

[0052] f. Pre-clamping of clamping jaws: Activate clamping jaws 12 to clamp the outer wall of shaft-type workpieces;

[0053] g. The loading clamping fixture 20 releases the workpiece and returns it to its initial position, and then the friction welding process is carried out, which completes the friction welding process such as the installation and positioning of the ring component, the friction of the weldment, and the pressure holding at the top.

[0054] h. After friction welding is completed, remove the welded workpiece and machine it to smooth out the circular groove section.

[0055] Example 2:

[0056] For tubular workpieces to be welded, such as steel pipes with an inner diameter of φ28~62mm, Figures 4-5 As shown, a method for precisely clamping workpieces for inertial friction welding is characterized by employing a welding clamping fixture 10 and a feeding fixture 20. The welding clamping fixture 10 is mounted on the spindle of a friction welding machine 100 and includes a fixture body 11, clamping jaws 12, and a push rod 13. A clamping hole 110 is provided at one end of the fixture body 11 away from the friction welding machine 100, and a push rod 13 is provided at the bottom of the clamping hole 110 (e.g., ...). Figure 4As shown: the clamping hole 110 and the push rod 13 are coaxial with the tooling body 11 and the main shaft of the friction welding machine 100. The inner wall of the clamping hole 110 away from the main shaft of the friction welding machine 100 and the clamping claws 12 are evenly arranged around the axis of the tooling body 11 (the clamping claws 12 are set according to the actual situation and can be controlled by a pneumatic drive device). The push rod 13 is a tapered structure with a diameter that gradually decreases from the direction close to the friction welding machine 100 to the direction away from the friction welding machine 100. The outer wall of the push rod 13 (around its axis) is evenly provided with multiple snap-fit ​​ribs 130. The number of snap-fit ​​ribs 130 is determined according to the actual situation, preferably 5 to 8. The side of the clamping claws 12 near the central axis of the tooling body 11 is evenly provided with multiple first protruding ridges to increase the friction force and avoid damage to the workpiece 200 to be welded during the clamping process.

[0057] The loading fixture 20 includes a fixture base 21, a chuck connecting seat 22, a slide bar 23, a spring 24, and a chuck assembly. The fixture base 21 is connected to the end effector of the robot arm, and the chuck connecting seat 22 is installed inside the fixture base 21. Specifically, the cross-section of the fixture base 21 is an inverted "C" shape (e.g., Figure 4 As shown, the chuck connecting seat 22 is disposed inside the tooling seat 21 and is rotatably connected to the tooling seat 21 via a rotating shaft 210. Two adjacent sides of the chuck connecting seat 22 are respectively configured with a first chuck assembly 250 and a second chuck assembly 260 through components formed by a slide rod 23 and a spring 24. In this embodiment, the second chuck assembly 260 is used to clamp the tubular workpiece 200 to be welded. One end of the slide rod 23 is slidably connected to the chuck connecting seat 22, and the other end is fixedly connected to the second chuck assembly 260. A spring 24 is disposed on the outer wall of the slide rod 23, and both ends of the spring 24 are respectively connected to the second chuck assembly 260 and the chuck connecting seat 22. There are 2 to 5 slide rods (preferably 3), and correspondingly 2 to 5 springs 24 (preferably 3), and the slide rods 23 are evenly distributed around the axis of the second chuck assembly 260. A limiting ring 230 is disposed on the outer wall of the slide rod 23 to hard limit the compression of the spring 24.

[0058] The second chuck assembly 260 includes a connecting plate 251, a driving cavity 252, and a second chuck 261. The connecting plate 251 is fixedly connected to the end of the slide bar 23 away from the chuck connecting seat 22, and the driving cavity 252 is provided on the side of the connecting plate 251 away from the slide bar 23 (the driving cavity 252 is provided with a driving mechanism for driving the second chuck 261 to clamp shaft-type workpieces, and the clamping of the second chuck 261 can be achieved by a pneumatic mechanism). The second chuck 261 is provided on the side of the driving cavity 252 away from the connecting plate 251 (uniformly around the axis of the connecting plate 251). The number of second chucks 261 is 3 to 6. In this embodiment, 3 second chucks are selected. The inner wall of the end of the second chuck 261 away from the driving cavity 252 has an outer groove 2610, and the end face of the outer groove 2610 is provided with multiple third protruding ridges. The groove surface of the outer groove 2610 is set as an outwardly convex arc structure to match the inner wall of the tube-type workpiece.

[0059] The specific method for precise workpiece clamping is as follows:

[0060] a. Installation of welding clamping fixture: Install the welding clamping fixture 10 on the rotating spindle of the friction welding machine 100 and ensure that the welding clamping fixture 10 and the rotating spindle of the friction welding machine 100 are coaxial.

[0061] b. Pre-treatment of workpieces to be welded:

[0062] A second snap-fit ​​groove is machined on the end face of the tubular workpiece near the friction welding machine 100, corresponding to the snap-fit ​​rib 130 on the outer wall of the top rod 13.

[0063] c. The loading fixture is used to clamp the workpiece to be welded:

[0064] The second chuck 261 clamps the inner wall of the tubular workpiece and ensures that the side wall of the outer groove 2610 (i.e., the inner wall near the chuck connecting seat 22) abuts against the end face of the tubular workpiece away from the friction welding machine 100 (e.g., ...). Figure 4 As shown); a pressure sensor can be installed on the second chuck 261 to detect the pressure during the clamping process. When the pressure reaches 0.1 to 0.7 MPa, the pressure sensor feeds back a signal, and the robot control system runs the second chuck 261 for a length of 20 to 50 mm (preferably 30 mm); the groove depth of the outer groove 2610 is 5 to 8 mm (preferably 6.5 mm).

[0065] d. The workpiece to be welded is clamped into the welding clamping fixture: The robot arm moves to the preset position of the end of the robot arm and puts the end of the workpiece to be welded away from the loading fixture 20 into the clamping hole 110 (this step can be done using existing conventional control methods, which can be understood by those skilled in the art). At this time, the end face of the workpiece to be welded 200 does not contact the push rod 13, and the axis of the workpiece to be welded 20 is initially positioned with the axis of the main shaft of the friction welding machine 100.

[0066] e. Internal positioning of the workpiece to be welded: After the robot arm initially positions the workpiece 200 to be welded, the workpiece 200 is moved along the main axis of the friction welding machine 100 by the robot arm. The end of the workpiece 200 close to the friction welding machine 100 gradually contacts the push rod 13. During the translation, the workpiece is finely adjusted in real time to ensure that the push rod 13 is fully inserted into the inner hole of the tubular workpiece and the locking rib 130 is correspondingly locked in the second locking groove (during the movement, the welding clamping fixture 10 can be slowly rotated first to ensure that the locking rib 130 is correspondingly locked in the second locking groove, and then the robot arm is finely adjusted so that the push rod 13 is fully locked in the inner hole of the tubular workpiece). Continue to translate. When the slide rod 23 slides and the spring 24 is compressed to the preset pressure (which can be monitored by setting a pressure sensor), stop the movement of the robot arm. The preset pressure is 0.1 to 0.7 MPa.

[0067] f. Pre-clamping of clamping jaws: Activate clamping jaws 12 to clamp the outer wall of the tubular workpiece;

[0068] g. The loading clamping fixture 20 releases the workpiece and returns it to its initial position, and then the friction welding process is carried out, which completes the friction welding process such as the installation and positioning of the ring component, the friction of the weldment, and the pressure holding at the top.

[0069] h. After friction welding is completed, remove the welded workpiece and machine it to smooth the second snap-fit ​​groove section.

[0070] Example 3:

[0071] As a further optimization of the present application, based on Embodiment 1 or Embodiment 2, a dedicated motor is set to control the relative rotation of the chuck connecting seat 22 and the tooling seat 21, thereby completing the switching between the first chuck assembly 250 and the second chuck assembly 260.

[0072] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for precisely clamping workpieces for inertial friction welding, applicable to the clamping of shaft / tube workpieces, characterized in that: The system employs a welding clamping fixture and a feeding fixture. The welding clamping fixture includes a fixture body, clamping jaws, and a push rod. The feeding fixture includes a fixture base, a chuck connecting seat, a slide rod, a spring, and a chuck assembly. The fixture base is connected to the end of the robot arm, and a chuck connecting seat is installed inside the fixture base. Two adjacent sides of the chuck connecting seat are respectively equipped with a first chuck assembly and a second chuck assembly through assemblies formed by the slide rod and the spring. The first chuck assembly and the second chuck assembly are used to clamp shaft-type workpieces and pipe-type workpieces to be welded, respectively. The welding clamping fixture is installed on the spindle of a friction welding machine. The fixture body has a clamping hole at the end away from the friction welding machine, and a push rod is installed at the bottom of the clamping hole. Clamping jaws are evenly arranged on the inner wall of the end of the clamping hole away from the friction welding machine spindle. The push rod is a tapered structure with a diameter that gradually decreases from the direction close to the friction welding machine to the direction away from the friction welding machine, and multiple snap-fit ​​ribs are evenly arranged on the outer wall of the push rod. The precise workpiece clamping method includes: a) installation of welding clamping fixture; b) pretreatment of the workpiece to be welded; c) clamping of the workpiece to be welded by the loading fixture; d) clamping of the workpiece to be welded into the welding clamping fixture; e) internal lifting of the workpiece to be welded; f) pre-clamping of the clamping jaws; g) releasing of the workpiece by the loading fixture.

2. The method for precisely clamping a workpiece for inertial friction welding according to claim 1, characterized in that: One end of the slide rod is slidably connected to the chuck connecting seat, and the other end is connected to the chuck assembly. A spring is provided on the outer wall of the slide rod, and the two ends of the spring are respectively connected to the chuck assembly and the chuck connecting seat.

3. The method for precisely clamping a workpiece for inertial friction welding according to claim 2, characterized in that: A limiting ring is provided on the outer wall of the slide bar.

4. The method for precisely clamping a workpiece for inertial friction welding according to claim 2, characterized in that: The chuck assembly includes a connecting plate, a driving cavity, and a chuck. The connecting plate is fixedly connected to the end of the slide rod away from the chuck connecting seat, and the driving cavity is provided on the side of the connecting plate away from the slide rod. The chuck is provided on the side of the driving cavity away from the connecting plate. The first chuck of the first chuck assembly has an inner groove on the inner wall of the end away from the driving cavity, and multiple second protruding ridges are provided on the end face of the inner groove. The second chuck of the second chuck assembly has an outer groove on the outer wall of the end away from the driving cavity, and multiple third protruding ridges are provided on the end face of the outer groove.

5. The method for precisely clamping a workpiece for inertial friction welding according to claim 4, characterized in that: The inner groove surface is configured as a concave arc-shaped structure, and the outer groove surface is configured as a convex arc-shaped structure.

6. The method for precisely clamping a workpiece for inertial friction welding according to claim 4, characterized in that: The precise workpiece clamping method is as follows: a. Installation of welding clamping fixture: Install the welding clamping fixture on the rotating spindle of the friction welding machine and ensure that the welding clamping fixture and the rotating spindle of the friction welding machine are coaxial; b. Pre-treatment of workpieces to be welded: For shaft-type workpieces: A circular groove is machined on the end face of the shaft-type workpiece closest to the friction welding machine according to the diameter of the push rod, and a first snap-fit ​​groove is machined on the outer wall of the circular groove corresponding to the snap-fit ​​rib on the outer wall of the push rod. For tubular workpieces: A second snap-fit ​​groove is machined on the end face of the tubular workpiece near the friction welding machine to correspond to the snap-fit ​​rib on the outer wall of the push rod; c. The loading fixture is used to clamp the workpiece to be welded: For shaft-type workpieces: the first chuck of the first chuck assembly clamps the outer wall of the shaft-type workpiece and ensures that the inner groove sidewall abuts against the end face of the shaft-type workpiece away from the friction welding machine; For tubular workpieces: The inner wall of the tubular workpiece is clamped by the second clamp of the second clamp assembly, and the outer groove sidewall is pressed against the tubular workpiece. d. The workpiece to be welded is clamped into the welding clamping fixture: The robot arm moves to the preset end position and places the end of the workpiece away from the loading fixture into the clamping hole. At this time, the end face of the workpiece to be welded does not contact the push rod, and the axis of the workpiece to be welded is initially positioned with the axis of the friction welding machine spindle. e. Internal positioning of the workpiece to be welded: After the robot arm initially positions the workpiece to be welded, it controls the workpiece to be welded to move along the main axis of the friction welding machine. The end of the workpiece to be welded that is close to the friction welding machine gradually contacts the push rod. During the translation, the workpiece to be welded is finely adjusted in real time to ensure that the push rod is fully engaged in the circular groove of the shaft workpiece or the inner hole of the tube workpiece, and the locking rib is engaged in the first locking groove or the second locking groove. Continue to translate until the slide bar slides and the spring is compressed to the preset pressure, then stop the movement of the robot arm. f. Clamping jaws pre-clamping: Activate the clamping jaws to clamp the outer wall of shaft or tube workpieces; g. The loading clamping fixture releases the workpiece and returns it to its initial position, and then the friction welding process is carried out.

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