A clamping tool for linear friction welding and a linear friction welding method

Abstract

The present application relates to a kind of linear friction welding clamping tool, applied to the part with large size asymmetric complex cross section, including clamping body and the first wedge, second wedge, multiple toothed wedge block assembly adapted with clamping body;Wherein, the upper and lower ends of clamping body are respectively provided with the first inclined surface groove, second inclined surface groove corresponding with the first wedge, second wedge, and the end surface of clamping body is contacted with part is provided with multiple grooves;Toothed wedge block assembly includes tooth block and the wedge block attached to the both sides of tooth block, the contact surface of tooth block and wedge block is inclined surface, tooth block is used to insert the slot of part and be fixed in corresponding recess by two wedge blocks.The present application also relates to a kind of linear friction welding method.The purpose of the linear friction welding clamping tool is to solve the problem that large size asymmetric complex cross section part is difficult to disassemble after welding, internal crack defect is prone to occur.

Description

Technical Field

[0001] This invention relates to the field of linear friction welding technology, and more specifically to a clamping fixture and linear welding method for linear friction welding. Background Technology

[0002] Linear friction welding is a welding method that has developed rapidly in recent years, mainly used in the manufacture of titanium alloy parts. Workpiece 2 vibrates linearly in the vertical direction at a certain frequency and amplitude; workpiece 1 contacts the end face of workpiece 2 under the action of a forging force in the horizontal direction. High-frequency friction generates heat on the contact surface. As the temperature rises, the material on the contact surface softens and is extruded. When the extrusion reaches a certain extent, the vibration is quickly stopped, and a forging force is applied to join the two workpieces together, completing the welding process.

[0003] During welding, the welding load is significant, including the welding force in the vertical direction (vibration direction) and the upsetting force in the horizontal direction (upsetting direction). Therefore, reliable fixation of both ends of the "welded parts" is necessary. Currently, a common method for fixing the "welded parts" is to use a set of wedges to apply a vertical clamping force. When the "upper wedge" is tightened onto the "clamping body" with two screws, the "upper wedge" moves to the left. Due to the inclined plane, this drives the "lower wedge" to move downwards vertically. The "lower pad" provides support from below, achieving reliable clamping of the "welded parts." The upsetting force borne by the "welded parts" is transmitted to the "clamping body" through the "rear pad."

[0004] When the "welded parts" are subjected to a vertical clamping force, they will be compressed, resulting in a certain amount of compressive deformation. This compressive deformation is elastic deformation, and it will fully recover after the pressure is released. When the two ends of the "welded parts" to be welded are compressed by approximately the same clamping force, in addition to producing approximately the same amount of compressive deformation, compressive stress is also generated inside the "welded parts." During the welding process, the two "welded parts" are joined together under the action of frictional heat, and the compressive stress in the material at the weld joint disappears under the action of frictional heat. After welding is completed, when the "upper wedge" is released, the external clamping force is eliminated, and the elastic compressive deformation of the material outside the weld joint will recover, generating tensile stress on the weld joint.

[0005] When the length L of the "welded part" in the vibration direction is small, the amount of compressive deformation after clamping is small, and the tensile stress on the weld is small. When the length L of the "welded part" in the vibration direction is large, the amount of compressive deformation after clamping is large, the tensile stress on the weld is large, and it may even lead to internal cracks at the weld.

[0006] Therefore, the inventors provide a clamping fixture and a linear friction welding method for linear friction welding. Summary of the Invention

[0007] (1) Technical problems to be solved

[0008] This invention provides a clamping fixture and a linear friction welding method for linear friction welding, which solves the technical problems of difficult disassembly and easy internal cracking defects of large-sized asymmetrical complex cross-section parts after welding.

[0009] (2) Technical solution

[0010] This invention provides a linear friction welding clamping fixture for parts with large, asymmetrical, and complex cross-sections. The fixture includes a clamping body and a first wedge, a second wedge, and a plurality of toothed wedge assemblies adapted to the clamping body.

[0011] The upper and lower ends of the clamping body are respectively provided with a first inclined groove and a second inclined groove corresponding to the first wedge and the second wedge, and multiple grooves are provided on the end face of the clamping body that contacts the part;

[0012] The toothed wedge assembly includes a toothed block and wedges attached to both sides of the toothed block. The contact surface between the toothed block and the wedges is an inclined surface. The toothed block is used to insert into the groove of the part and is fixed in the corresponding groove by the two wedges.

[0013] Furthermore, the plurality of grooves includes a first groove adapted to the inclined clamping platform of the part, a second and a third groove located between the inclined clamping platform and the upper end of the clamping body and symmetrically distributed from left to right, and a fourth and a fifth groove located between the inclined clamping platform and the lower end of the clamping body and symmetrically distributed from left to right.

[0014] Furthermore, the plurality of grooves also includes a sixth groove disposed opposite to the first groove.

[0015] Furthermore, each tooth in the tooth block has an angle.

[0016] Furthermore, the included angle between the two inclined surfaces in each tooth is 1 to 3°.

[0017] Furthermore, the first inclined groove and the second inclined groove are symmetrically arranged at the upper and lower ends of the clamping body.

[0018] Furthermore, the linear friction welding clamping fixture also includes an upper wedge, a middle wedge, and a lower wedge, which cooperate to fix the inclined clamping platform of the part.

[0019] The present invention also provides a linear friction welding method using the above-mentioned linear friction welding clamping fixture, comprising the following steps:

[0020] The part is installed in the fixture, and multiple toothed blocks are inserted into the slots of the part;

[0021] Install the first wedge and the second wedge to fix the upper and lower ends of the part;

[0022] The fixed parts are then subjected to linear friction welding.

[0023] Furthermore, the upsetting force for linear friction welding is 0.1σ. s ~0.3σ s , where σ s The room temperature yield strength of the material being welded.

[0024] Furthermore, the holding time for the upsetting force is 4 to 8 minutes.

[0025] (3) Beneficial effects

[0026] In summary, by using multiple toothed wedge components and machining corresponding grooves on the part's "clamping table," the welding force in the vertical direction (vibration direction) is borne jointly by dozens of teeth. The shear stress borne by each tooth is small, far below the allowable shear stress of a tooth. Since the part is fixed in sections by multiple toothed wedge components, it can be considered that the part has no compressive deformation or compressive stress in the vertical direction, thus reducing the internal stress of the part during the welding process. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is an assembly elevation view of a linear friction welding clamping fixture and a part provided in an embodiment of the present invention;

[0029] Figure 2 This is a front view of the assembly of a linear friction welding clamping fixture and a part provided in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the structure of a part to be welded according to an embodiment of the present invention;

[0031] Figure 4 This is an elevation view of a linear friction welding clamping fixture provided in an embodiment of the present invention;

[0032] Figure 5This is a front view of a linear friction welding clamping fixture provided in an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of the toothed wedge assembly in a linear friction welding clamping fixture provided in an embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of a linear friction welding process provided in an embodiment of the present invention.

[0035] In the picture:

[0036] 1-Clamping body; 101-First inclined groove; 102-Second inclined groove; 1031-First groove; 1032-Second groove; 1033-Third groove; 1034-Fourth groove; 1035-Fifth groove; 1036-Sixth groove; 2-First wedge; 3-Second wedge; 4-Toothed wedge assembly; 401-Toothed block; 402-Wedge; 5-Upper wedge; 6-Middle wedge; 7-Lower wedge; 100-Part; 1001-Clamping table; 1002-Welding table; 1003-Inclined clamping table; 1004-Inclined welding table; 1005-Welding surface; 1006-Groove. Detailed Implementation

[0037] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention. That is, the present invention is not limited to the described embodiments, and any modifications, substitutions and improvements to the parts, components and connection methods are covered without departing from the spirit of the present invention.

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0040] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "install" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] Figure 1 This is an assembly diagram of a linear friction welding clamping fixture provided in an embodiment of the present invention, applicable to parts with large-sized, asymmetrical, and complex cross-sections, such as... Figure 1-6 As shown, the clamping fixture may include a clamping body 1 and a first wedge 2, a second wedge 3, and a plurality of toothed wedge assemblies 4 adapted to the clamping body 1; the upper and lower ends of the clamping body 1 are respectively provided with a first inclined groove 101 and a second inclined groove 102 corresponding to the first wedge 2 and the second wedge 3, and a plurality of grooves are provided on the end face of the clamping body 1 that contacts the part 100.

[0042] The toothed wedge assembly 4 includes a toothed block 401 and wedges 402 attached to both sides of the toothed block 401. The contact surface between the toothed block 401 and the wedges 402 is an inclined surface. The toothed block 401 is used to insert into the groove of the part 100 and is fixed in the corresponding groove by the two wedges 402.

[0043] In the above embodiments, it should be noted that a part with a large-sized asymmetrical complex cross-section refers to a part with a height greater than 500mm and an asymmetrical irregular shape in cross-section.

[0044] like Figure 3 As shown, one piece is placed on each side during welding, and the connection is achieved through heat generated by contact friction on the welding surface 1005. Its structural characteristics are as follows:

[0045] The area of ​​weld surface 1005 is as high as 9500 mm². 2 To achieve linear friction welding, following conventional linear friction welding processes, the vertical friction pressure is 0.8 to 1 times the 0.5Tm yield strength, approximately 40 to 50 MPa, while the horizontal upsetting force is generally 1 to 1.5 times the friction pressure, i.e., 40 to 75 MPa. With a height of 690 mm, a width of 50.5 mm, and a clamping table 1001 thickness of 20 mm, linear friction welding of the part is achieved after clamping and fixing by applying a vertically downward clamping force to the top surface of this slender structure, following normal specimen clamping methods.

[0046] For parts with this special structure, the traditional clamping method involves applying a vertically downward clamping force to the top surface of the part. However, this traditional clamping method often results in insufficient clamping force, causing relative movement between the part and the fixture. This makes disassembly after welding extremely difficult. Upon disassembly, it is found that multiple friction welds have occurred at the contact surfaces of the part and the fixture, further complicating disassembly. Furthermore, the insufficient relative friction between the two parts prevents the welding surface 1005 from generating enough frictional heat, hindering welding. Increasing the clamping force to prevent relative movement between the part and the fixture compresses the slender part by 3.42 mm. However, the excessive internal compressive stress exceeds the allowable value, causing the part to undergo high-frequency elastic deformation under a welding force of approximately 50 tons, resulting in internal cracks after welding.

[0047] Several sets of grooves 1006 are machined on both sides of the clamping table 1001 of part 100. Each set of grooves 1006 contains several grooves with a certain width B and depth H.

[0048] Among them, the wedge 402 is an L-shaped wedge, the horizontal part of which contacts the toothed block 401, and the vertical part of which is used to fix it to the clamp body 1 by screws.

[0049] As an optional implementation method, such as Figure 5 As shown, the multiple grooves include a first groove 1031 adapted to the inclined clamping platform 1003 of the part, a second groove 1032 and a third groove 1033 located between the inclined clamping platform 1003 and the upper end of the clamping body 1 and symmetrically distributed from left to right, and a fourth groove 1034 and a fifth groove 1035 located between the inclined clamping platform and the lower end of the clamping body 1 and symmetrically distributed from left to right. Specifically, each groove has the same structural dimensions, and each groove has a threaded hole at the top and bottom.

[0050] As an optional implementation method, such as Figure 5 As shown, the plurality of grooves also includes a sixth groove 1036 disposed opposite to the first groove. The sixth groove 1036 facilitates the horizontal fixing and clamping of the inclined clamping table 1003.

[0051] As an optional implementation method, such as Figure 6 As shown, each tooth in the tooth block 401 has a chamfer. The chamfer of the teeth on the tooth block 401 is set to facilitate assembly with the corresponding slots on the part 100.

[0052] As an alternative implementation, the included angle between the two inclined surfaces in each tooth is 1 to 3°. Smaller angles lead to assembly difficulties, while larger angles reduce the contact area between the tooth surface and the groove surface, thus decreasing the load-bearing capacity.

[0053] As an optional implementation method, such as Figure 5 As shown, the first inclined groove 101 and the second inclined groove 102 are symmetrically arranged at the upper and lower ends of the clamping body 1. The first wedge 101 presses against the top surface of the part 100 with a small force, and the second wedge 102 abuts against the bottom surface of the part 100 with a small force, thereby achieving vertical fixed clamping of the part 100.

[0054] As an optional implementation method, such as Figure 2 As shown, the linear friction welding clamping fixture also includes an upper wedge 5, a middle wedge 6, and a lower wedge 7, which are used in conjunction with the inclined clamping table to fix the part 100.

[0055] Specifically, the cooperation between the upper wedge 5, the middle wedge 6 and the lower wedge 7 can fix and clamp the inclined clamping table 1003.

[0056] Figure 7 This is a schematic flowchart of a linear friction welding method using the above-described linear friction welding clamping fixture, provided by an embodiment of the present invention. The method may include the following steps:

[0057] S100. Install the part in the fixture and insert multiple toothed blocks into the slots of the part;

[0058] S200, Install the first wedge and the second wedge to fix the upper and lower ends of the part;

[0059] S300, perform linear friction welding on the fixed parts.

[0060] In the above embodiment, in step S100, L-shaped wedges are placed above and below each tooth block, and the L-shaped wedges are fixed in the threaded holes of the clamp body with screws. All L-shaped wedges are tightened evenly with screws.

[0061] In step S200, the first wedge and the second wedge are installed. The installation process for both is the same. Taking the first wedge as an example, the first wedge is pushed with a screw with a small force to eliminate the gap between the upper and lower surfaces of the first wedge, so that the first wedge presses against the top surface of the part with a small force. Similarly, the second wedge presses against the bottom surface of the part with a small force.

[0062] In step S300, after fixing the fixture to the equipment, the parts are fixed in the fixture according to the above method. The upper, lower, left and right sides of the weld are aligned. The two sides of the surface to be welded are cleaned with alcohol before linear friction welding is started. The welding process parameters are: amplitude 2mm, frequency 50Hz, and friction pressure 50MPa.

[0063] Specifically, when the part has an inclined clamping platform, the middle wedge is placed at the acute angle of the inclined clamping platform, and then the upper and lower wedges are placed in, and the upper and lower wedges are fixed to the clamping body. After welding, the vibrating side wedges and toothed blocks are released, and the part is removed from the vibrating side. The weld quality of the part after welding is good, and there are no internal cracks or defects.

[0064] As an optional implementation, the upsetting force for linear friction welding is 0.1σ. s ~0.3σ s , where σ s This refers to the room temperature yield strength of the material being welded. Specifically, increasing the upsetting force from 50–80 MPa to 100–150 MPa allows for the extrusion of more ductile metal, reduces residual stress in the thermoplastic metal during cooling, and decreases the tendency for internal cracking.

[0065] As an optional implementation, the holding time of the upsetting force is 4 to 8 minutes. Specifically, extending the holding time of the upsetting force to 4 to 8 minutes can allow for more complete atomic diffusion at the weld, thus ensuring weld quality.

[0066] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.

[0067] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art without departing from the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A linear friction welding clamping fixture, characterized in that, Applied to parts with large-sized asymmetrical complex cross-sections, including a clamping body (1) and a first wedge (2), a second wedge (3), and a plurality of toothed wedge assemblies (4) adapted to the clamping body; wherein, The upper and lower ends of the clamping body (1) are respectively provided with a first inclined groove (101) and a second inclined groove (102) corresponding to the first wedge (2) and the second wedge (3). Multiple grooves are provided on the end face of the clamping body (1) that contacts the part (100). The toothed wedge assembly (4) includes a toothed block (401) and wedges (402) attached to both sides of the toothed block (401). The contact surface between the toothed block (401) and the wedges (402) is an inclined surface. The toothed block (401) is used to insert into the groove of the part (100) and is fixed in the corresponding groove (103) by the two wedges (402). The plurality of grooves include a first groove (1031) adapted to the inclined clamping platform of the part, a second groove (1032) and a third groove (1033) located between the inclined clamping platform and the upper end of the clamping body (1) and symmetrically distributed from left to right, and a fourth groove (1034) and a fifth groove (1035) located between the inclined clamping platform and the lower end of the clamping body (1) and symmetrically distributed from left to right.

2. The linear friction welding clamping fixture according to claim 1, characterized in that, The plurality of grooves also includes a sixth groove (1036) disposed opposite to the first groove.

3. The linear friction welding clamping fixture according to claim 1, characterized in that, Each tooth in the tooth block (401) has an angle.

4. The linear friction welding clamping fixture according to claim 3, characterized in that, The angle between the two facets with an inclination in each tooth is 1 to 3°.

5. The linear friction welding clamping fixture according to claim 1, characterized in that, The first inclined groove (101) and the second inclined groove (102) are symmetrically arranged at the upper and lower ends of the clamp body (1).

6. The linear friction welding clamping fixture according to claim 1, characterized in that, It also includes an upper wedge (5), a middle wedge (6) and a lower wedge (7), wherein the upper wedge (5), the middle wedge (6) and the lower wedge (7) are all placed in the first groove and are used to cooperate in fixing the part (100) by a slanted clamping table.

7. A linear friction welding method using the linear friction welding clamping fixture as described in any one of claims 1-6, characterized in that, The method includes the following steps: The part is installed in the fixture, and multiple toothed blocks are inserted into the slots of the part; Install the first wedge and the second wedge to fix the upper and lower ends of the part; The fixed parts are then subjected to linear friction welding.

8. The linear friction welding method according to claim 7, characterized in that, The upsetting force for linear friction welding is 0.1σ. s ~0.3σ s , where σ s The room temperature yield strength of the material being welded.

9. The linear friction welding method according to any one of claims 8, characterized in that, The holding time for the upsetting force is 4 to 8 minutes.

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