Auxiliary cooling device for friction welding of annular pipe structure and working method of auxiliary cooling device

Abstract

The invention provides an auxiliary cooling device for friction welding of a ring pipe structure and a working method of the auxiliary cooling device, and belongs to the technical field of friction welding. The problems that in the prior art, due to the fact that the surface of an inner ring of a large-diameter-thickness-ratio ring material dissipates heat slowly, the cooling speed of a welding area is uneven, residual stress is increased, the strength of a welding joint is affected, and due to the fact that the surface of the inner ring dissipates heat slowly, microstructure changes are uneven, and the mechanical property of the material is affected are solved. The device comprises a tailstock side clamp, a main shaft side clamp, an inert gas connecting pipe, a gas nozzle and a cooling medium spraying mechanism, the tailstock side clamp is installed in a movable sliding table box body of friction welding equipment, a tailstock side part to be welded is clamped in the tailstock side clamp, a main shaft side part to be welded is clamped in the main shaft side clamp, and the inert gas connecting pipe is connected with the gas nozzle. An inert gas connecting pipe is arranged in the main shaft side to-be-welded part, the outlet end of the inert gas connecting pipe is connected with the gas nozzle, and a cooling medium spraying mechanism is arranged on the inner side of the tailstock side to-be-welded part. The device is mainly used for cooling the welding seam of friction welding.

Description

Technical Field

[0001] The invention belongs to the technical field of friction welding, and in particular relates to an auxiliary cooling device for friction welding of an annular structure and a working method thereof. Background Art

[0002] In recent years, inertia friction welding has the advantages of fewer process parameters, high stability, less heat input, narrow weld range, and high joint mechanical properties. It has great potential in the industrial field. Many products are used in the aerospace field, etc. The existing inertia friction welding process is: the workpieces to be welded are fixed at the rotating end and the sliding end respectively. When the rotation speed of the rotating end reaches the set value, the drive motor of the spindle is separated from the rotating end, and the sliding end is driven by the hydraulic servo to move toward the rotating end, generating friction heat at the contact interface. Due to the action of friction, the material undergoes plastic deformation at the welding interface, and the temperature of the material gradually increases. When the rotation speed reaches the set value, the sliding end is driven by the hydraulic servo to move toward the rotating end. Friction heat is generated at the contact interface. Due to the action of friction, the material undergoes plastic deformation at the welding interface, and the temperature of the material gradually increases. When the rotation speed of the rotating end drops to a certain value, the workpiece to be welded begins to be forged. After maintaining for a certain period of time, the sliding end withdraws. After welding, heat treatment is carried out according to the corresponding material properties and post-welding and performance requirements. A quenching heat treatment process is performed after welding, especially for the ring tube structure, which is welded by inertia friction welding. For example, the gear ring transmission components used in the fields of automobiles, machine tools, wind power, etc. need to withstand the forces from the transmission force and load during operation. Therefore, they need to have sufficiently high strength and meet higher comprehensive mechanical properties of the material. Therefore, it is necessary to perform a quenching process on the weld after inertia friction welding.

[0003] However, since the heat dissipation of the inner ring surface of the annular tube structure is slow after welding, and the heat dissipation of the outer ring surface is fast, the cooling rate of the welding area is uneven, which in turn causes a gradient change in the residual stress, affecting the strength of the welded joint. The slow heat dissipation of the inner ring surface will also lead to uneven changes in the microstructure. Based on the above problems, the present invention proposes an auxiliary cooling device for friction welding of annular tube structures and a working method thereof. Summary of the invention

[0004] In view of this, the present invention aims to propose an auxiliary cooling device and working method for friction welding of annular structures, so as to solve the problems in the prior art that the heat dissipation on the inner ring surface of the ring material with a large diameter-to-thickness ratio is slow, the cooling rate in the welding area is uneven, which will lead to an increase in residual stress and affect the strength of the welded joint, and the slow heat dissipation on the inner ring surface will lead to uneven changes in the microstructure and affect the mechanical properties of the material.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] An auxiliary cooling device for friction welding of an annular structure comprises a tailstock side fixture, a spindle side fixture, an inert gas connecting pipe, a gas nozzle and a cooling medium spray mechanism, wherein the tailstock side fixture is installed in a movable slide box of the friction welding device, and a tailstock side workpiece to be welded is clamped in the tailstock side fixture, the spindle side fixture is installed in a spindle side box of the friction welding device, and a spindle side workpiece to be welded is clamped in the spindle side fixture, an inert gas connecting pipe is arranged in the spindle side workpiece to be welded, and the outlet end of the inert gas connecting pipe is connected to the gas nozzle, a cooling medium spray mechanism is arranged inside the tailstock side workpiece to be welded, and the cooling medium spray mechanism and the gas nozzle are both located at the weld between the spindle side workpiece to be welded and the tailstock side workpiece to be welded.

[0007] Furthermore, the cooling medium spray mechanism includes a cooling medium connecting pipe, an internal air pipe, an atomizing nozzle and a cooling medium nozzle. The cooling medium connecting pipe is arranged on the inner side of the workpiece to be welded on the tailstock side, and the internal air pipe is arranged in the cooling medium connecting pipe. The air outlet of the internal air pipe is located in the cooling medium nozzle. The cooling medium nozzle is connected to the cooling medium connecting pipe through a transition joint. A plurality of atomizing nozzles are evenly distributed on the outside of the cooling medium nozzle, and a plurality of air outlet holes are arranged at the air outlet of the internal air pipe.

[0008] Furthermore, a partition is provided in the cooling medium nozzle, the partition is sleeved on the outside of the internal air pipe and is located at a part of the internal air pipe without an air outlet, and a through hole is provided on the partition.

[0009] Furthermore, the internal gas pipe is connected to the output pipeline of the gas source through a gas nozzle elbow, the cooling medium connecting pipe is connected to the output pipeline of the cooling medium source through a cooling medium pipe elbow, and the inert gas connecting pipe is connected to the output pipeline of the inert gas source.

[0010] Furthermore, the cooling medium connecting pipe is installed in a U-shaped groove provided on a fixed seat in the movable slide box.

[0011] Furthermore, the side surface of the fixing seat is connected to the telescopic mechanism.

[0012] Furthermore, the telescopic mechanism includes a telescopic cylinder and a connecting rod, one end of the connecting rod is connected to the output end of the telescopic cylinder, and the other end is connected to a fixed seat, and the fixed end of the telescopic cylinder is installed in the movable slide box.

[0013] Furthermore, the telescopic cylinder, the inert gas source, the air source and the cooling medium source are all connected to a control system.

[0014] Furthermore, the gas nozzle is evenly distributed with a plurality of gas injection holes.

[0015] A working method for an annular structure friction welding auxiliary cooling device, comprising the following steps:

[0016] Step 1: Before welding, clamp and fix the workpiece on the tailstock side with the tailstock side clamp, and clamp and fix the workpiece on the spindle side with the spindle side clamp;

[0017] Step 2: During welding, the control system controls the spindle side to fill with inert gas to protect the welding process;

[0018] Step 3: The control system controls the telescopic cylinder to adjust the position of the cooling medium nozzle to the welding area;

[0019] Step 4: According to the required cooling effect, spray the required amount of cooling medium through the atomizing nozzle to ensure the effect of the welding joint.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. After welding, the present invention sprays aerosol through the internal atomizing nozzle to quickly cool the inside of the weld joint, so that the cooling of the inside and outside of the ring tube structure is unified, and the quenching effect is achieved at the same time. The welding environment is quickly cooled to below room temperature, and the ring tube forms a martensitic structure as a whole, which can greatly enhance the strength of the weld.

[0022] 2. The present invention can promote the formation of a fine grain structure of the metal during the welding process through rapid cooling, thereby improving the strength and toughness of the welded joint. The fine grain structure usually means more uniform mechanical properties and better tensile strength.

[0023] 3. The present invention controls the cooling rate. The mist cooling can help reduce the residual stress gradient in the weld joint, help the weld area reach a stable state faster, improve the quality and reliability of the weld joint as a whole, promote the crystallization process of the metal in a unified manner, reduce the occurrence of welding defects, and improve the performance of the weld joint.

[0024] 4. After welding, the present invention sprays aerosol through the internal atomizing nozzle to rapidly cool the welding joint of the annular tube structure, which can quickly cool the welding joint, reduce the diffusion range of the heat-affected zone, ensure that other positions of the annular tube workpiece are not affected, and improve the quality of the weld.

[0025] 5. After welding, the present invention cools the weld joint, which can strengthen the softening zone of the joint, improve the room temperature and high temperature tensile strength of the weld joint and the hardness of the weld joint, change the joint structure, and improve the performance of the weaker material weakened zone when connecting dissimilar materials.

[0026] 6. Rapid cooling of the weld in time after welding can achieve the quenching effect, which can reduce the final heat treatment process in the friction welding process, reduce the process steps, improve work efficiency, and reduce the secondary heating process of the weld, so that the weld structure can be formed in one time, further improving efficiency.

[0027] 7. The present invention sprays inert gas during the welding process to provide oxidation protection during the welding process, prevent the metal at the weld from oxidizing with oxygen in the air, maintain the purity of the metal at the weld, reduce the formation of an oxide layer, and thus improve the welding quality. Spraying inert gas can protect the metal at the weld from external gas contamination during the welding process, reduce the formation of inclusions and pores at the weld, and improve the sealing and strength of the welded joint.

[0028] 8. The present invention can help to adjust the temperature distribution of the welding area of ​​the pipe structure to be more uniform by injecting inert gas inside, reduce the temperature gradient during welding, alleviate the influence of thermal stress, and reduce the risk of deformation and cracks during welding.

[0029] 9. The present invention sprays inert gas on the inner wall to reduce spark splashing generated during welding, reduce harm to operators and equipment, improve the safety of the working environment, reduce defects that may occur during welding, and improve the quality and reliability of welded joints.

[0030] 10. The present invention can adjust the position of the internal aerosol spray assembly at any time. Since the weld position changes during the welding process, the position of the internal aerosol spray assembly can be controlled by the telescopic cylinder so that the internal aerosol spray assembly always remains consistent with the weld position, thereby ensuring the stability of the cooling temperature at the weld. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0032] Figure 1 It is a structural schematic diagram of an auxiliary cooling device for friction welding of annular tube structure according to the present invention;

[0033] Figure 2 A partially enlarged schematic diagram of an auxiliary cooling device for friction welding of annular tube structure according to the present invention Figure 1 ;

[0034] Figure 3 The invention is a partially enlarged schematic diagram of a friction welding auxiliary cooling device for annular tube structure. Figure 2 .

[0035] 1-movable slide box, 2-telescopic cylinder, 3-connecting rod, 4-fixed seat, 5-tailstock side fixture, 6-cooling medium connecting pipe, 7-internal air pipe, 8-partition, 9-atomizing nozzle, 10-spindle side fixture, 11-spindle side box, 12-spindle side part to be welded, 13-inert gas connecting pipe, 14-gas nozzle, 15-cooling medium nozzle, 16-transition joint, 17-gas nozzle elbow, 18-cooling medium pipe elbow, 19-tailstock side part to be welded. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0037] See also Figure 1-3 The present embodiment is described, which is an auxiliary cooling device for friction welding of an annular tube structure, comprising a tailstock side fixture 5, a spindle side fixture 10, an inert gas connecting pipe 13, a gas nozzle 14 and a cooling medium spray mechanism, wherein the tailstock side fixture 5 is installed in a movable slide box 1 of the friction welding equipment, and a tailstock side workpiece 19 to be welded is clamped in the tailstock side fixture 5, the spindle side fixture 10 is installed in a spindle side box 11 of the friction welding equipment, and a spindle side workpiece 12 to be welded is clamped in the spindle side fixture 10, an inert gas connecting pipe 13 is provided in the spindle side workpiece 12 to be welded, the outlet end of the inert gas connecting pipe 13 is connected to the gas nozzle 14, a cooling medium spray mechanism is provided inside the tailstock side workpiece 19 to be welded, and the cooling medium spray mechanism and the gas nozzle 14 are both located at the weld between the spindle side workpiece 12 to be welded and the tailstock side workpiece 19 to be welded.

[0038] The cooling medium spray mechanism includes a cooling medium connecting pipe 6, an internal air pipe 7, an atomizing nozzle 9 and a cooling medium nozzle 15. The cooling medium connecting pipe 6 is arranged on the inner side of the workpiece to be welded 19 on the tailstock side. The internal air pipe 7 is arranged in the cooling medium connecting pipe 6. The air outlet of the internal air pipe 7 is located in the cooling medium nozzle 15. The cooling medium nozzle 15 is connected to the cooling medium connecting pipe 6 through a transition joint 16. A plurality of atomizing nozzles 9 are evenly distributed on the outside of the cooling medium nozzle 15. A plurality of air outlet holes are arranged at the air outlet of the internal air pipe 7.

[0039] The side surface of the fixing seat 4 is connected to the telescopic mechanism.

[0040] The telescopic mechanism includes a telescopic cylinder 2 and a connecting rod 3, one end of the connecting rod 3 is connected to the output end of the telescopic cylinder 2, and the other end is connected to a fixed seat 4. The fixed end of the telescopic cylinder 2 is installed in a movable slide box 1. The telescopic cylinder 2, an inert gas source, an air source, and a cooling medium source are all connected to a control system.

[0041] The telescopic mechanism can adjust the position where the cooling medium is sprayed according to the required weld position, thereby ensuring the accuracy of the cooling position and being able to quickly cool the weld joint position better.

[0042] Before welding, the workpiece 19 to be welded on the tailstock side is clamped and fixed by the tailstock side clamp 5, and the workpiece 12 to be welded on the spindle side is clamped and fixed by the spindle side clamp 10. During welding, the control system controls the spindle side to fill with inert gas to protect the welding process. The control system controls the telescopic cylinder 2 to adjust the position of the cooling medium nozzle 15 to the welding area. According to the required cooling effect, the required amount of cooling medium is sprayed through the atomizing nozzle 9 to ensure the effect of the welding joint.

[0043] The injection of inert gas during the welding process can provide oxidation protection during the welding process, prevent the metal at the weld from oxidizing with oxygen in the air, maintain the purity of the metal at the weld, reduce the formation of oxide layer, and thus improve the welding quality. The injection of inert gas can protect the metal at the weld from external gas contamination during welding, reduce the formation of inclusions and pores at the weld, improve the sealing and strength of the welded joint, help adjust the temperature distribution in the welding area to make it more uniform, reduce the temperature gradient during welding, reduce the impact of thermal stress, and reduce the risk of deformation and cracks during welding. It can reduce the spark splashing generated during welding, reduce the harm to operators and equipment, improve the safety of the working environment, reduce possible defects during welding, and improve the quality and reliability of welded joints.

[0044] During cooling, the cooling medium enters the cooling medium nozzle 15 through the cooling medium connecting pipe 6, and then the gas flows through the internal gas pipe 7 through the gas outlet and enters the cooling medium nozzle 15. After the gas and liquid are mixed, the gas mist is sprayed out through the atomizing nozzle 9 to cool the welding joint.

[0045] After welding, the use of gas mist cooling can quickly reduce the temperature of the weld joint, thereby effectively controlling the cooling rate of the welding area, preventing overheating that may occur during welding, and avoiding metal softening or thermal cracking caused by excessive temperature in the weld area. It can promote the formation of a fine grain structure in the metal during welding and improve the strength and toughness of the weld joint. A fine grain structure usually means more uniform mechanical properties and better tensile properties. By controlling the cooling rate, gas mist cooling can help reduce the residual stress that may occur in the weld joint, help the welding area reach a stable state faster, reduce the accumulation of thermal stress, reduce the level of residual stress, reduce the risk of deformation and cracking of the weld joint, improve the quality and reliability of the weld joint, promote the crystallization process of the metal, reduce the occurrence of welding defects, and improve the performance of the weld joint. The use of gas mist cooling will not produce a large amount of coolant discharge, which is more environmentally friendly than traditional water cooling.

[0046] A partition 8 is provided inside the cooling medium nozzle 15. The partition 8 is sleeved on the outside of the internal air pipe 7 and is located at a position where the internal air pipe 7 has no air outlet. A through hole is provided on the partition 8. The cooling medium can be water or other media. The cooling medium can be diverted when passing through the through holes on the partition, which can improve the uniformity of gas-liquid mixing and improve the cooling effect.

[0047] The internal gas pipe 7 is connected to the output pipeline of the gas source through the gas nozzle elbow 17, the cooling medium connecting pipe 6 is connected to the output pipeline of the cooling medium source through the cooling medium pipe elbow 18, and the inert gas connecting pipe 13 is connected to the output pipeline of the inert gas source.

[0048] The cooling medium connecting pipe 6 is installed in a U-shaped groove provided on the fixing seat 4 in the movable slide box 1, and the cooling medium connecting pipe 6 is clamped and fixed through the U-shaped groove.

[0049] The gas nozzle 14 is evenly distributed with a plurality of gas injection holes.

[0050] A working method for a friction welding auxiliary cooling device for an annular tube structure, comprising the following steps:

[0051] Step 1: Before welding, the workpiece 19 to be welded on the tailstock side is clamped and fixed by the tailstock side clamp 5, and the workpiece 12 to be welded on the spindle side is clamped and fixed by the spindle side clamp 10;

[0052] Step 2: During welding, the control system controls the spindle side to fill with inert gas to protect the welding process;

[0053] Step 3: The control system controls the telescopic cylinder 2 to adjust the position of the cooling medium nozzle 15 to the welding area;

[0054] Step 4: According to the required cooling effect, the required amount of cooling medium is sprayed through the atomizing nozzle 9 to ensure the effect of the welding joint.

[0055] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well.

Claims

1. An auxiliary cooling device for friction welding of annular tube structure, characterized in that: The invention comprises a tailstock side fixture (5), a spindle side fixture (10), an inert gas connecting pipe (13), a gas nozzle (14) and a cooling medium spray mechanism, wherein the tailstock side fixture (5) is installed in a movable slide box (1) of a friction welding device, a tailstock side workpiece to be welded (19) is clamped in the tailstock side fixture (5), the spindle side fixture (10) is installed in a spindle side box (11) of the friction welding device, a spindle side workpiece to be welded (12) is clamped in the spindle side fixture (10), an inert gas connecting pipe (13) is arranged in the spindle side workpiece to be welded (12), the outlet end of the inert gas connecting pipe (13) is connected to the gas nozzle (14), a cooling medium spray mechanism is arranged inside the tailstock side workpiece to be welded (19), and the cooling medium spray mechanism and the gas nozzle (14) are both located at the weld between the spindle side workpiece to be welded (12) and the tailstock side workpiece to be welded (19).

2. The auxiliary cooling device for friction welding of annular tube structure according to claim 1, characterized in that: The cooling medium spray mechanism comprises a cooling medium connecting pipe (6), an internal air pipe (7), an atomizing nozzle (9) and a cooling medium nozzle (15); the cooling medium connecting pipe (6) is arranged on the inner side of a workpiece to be welded (19) on the tailstock side; the internal air pipe (7) is arranged inside the cooling medium connecting pipe (6); the air outlet of the internal air pipe (7) is located inside the cooling medium nozzle (15); the cooling medium nozzle (15) is connected to the cooling medium connecting pipe (6) via a transition joint (16); a plurality of atomizing nozzles (9) are evenly distributed on the outer side of the cooling medium nozzle (15); and a plurality of air outlet holes are arranged at the air outlet of the internal air pipe (7).

3. The auxiliary cooling device for friction welding of annular tube structure according to claim 2, characterized in that: A partition plate (8) is provided inside the cooling medium nozzle (15), the partition plate (8) is sleeved on the outside of the internal air pipe (7) and is located at a portion of the internal air pipe (7) where there is no air outlet, and a through hole is provided on the partition plate (8).

4. The auxiliary cooling device for friction welding of annular tube structure according to claim 2, characterized in that: The internal gas pipe (7) is connected to the output pipeline of the gas source through a gas nozzle elbow (17), the cooling medium connecting pipe (6) is connected to the output pipeline of the cooling medium source through a cooling medium pipe elbow (18), and the inert gas connecting pipe (13) is connected to the output pipeline of the inert gas source.

5. The auxiliary cooling device for friction welding of annular tube structure according to claim 4, characterized in that: The cooling medium connecting pipe (6) is installed in a U-shaped groove provided on a fixed seat (4) in the movable slide box (1).

6. The auxiliary cooling device for friction welding of annular tube structure according to claim 4, characterized in that: The side surface of the fixing seat (4) is connected to the telescopic mechanism.

7. The auxiliary cooling device for friction welding of annular tube structure according to claim 6, characterized in that: The telescopic mechanism comprises a telescopic cylinder (2) and a connecting rod (3); one end of the connecting rod (3) is connected to the output end of the telescopic cylinder (2), and the other end is connected to a fixed seat (4); the fixed end of the telescopic cylinder (2) is installed in a movable slide box (1).

8. The auxiliary cooling device for friction welding of annular tube structure according to claim 7, characterized in that: The telescopic cylinder (2), the inert gas source, the air source and the cooling medium source are all connected to a control system.

9. The auxiliary cooling device for friction welding of annular tube structure according to claim 1, characterized in that: The gas nozzle (14) is evenly distributed with a plurality of gas injection holes.

10. A working method for the auxiliary cooling device for friction welding of annular tube structure according to any one of claims 1 to 9, characterized in that: It includes the following steps: Step 1: Before welding, the workpiece to be welded (19) on the tailstock side is clamped and fixed by the tailstock side clamp (5), and the workpiece to be welded (12) on the spindle side is clamped and fixed by the spindle side clamp (10); Step 2: During welding, the control system controls the spindle side to fill with inert gas to protect the welding process; Step 3: Control the telescopic cylinder (2) through the control system to adjust the position of the cooling medium nozzle (15) to the welding area; Step 4: According to the required cooling effect, the required amount of cooling medium is sprayed through the atomizing nozzle (9) to ensure the effect of the welding joint.

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