Linear friction welding apparatus and control method for cuboid workpieces

Abstract

The application provides a linear friction welding device and control method for cuboid workpieces, comprising an electro-hydraulic excitation system, an electro-hydraulic upsetting system and a clamping force control center; the electro-hydraulic excitation system and the electro-hydraulic upsetting system are respectively provided with clamping devices; the clamping device comprises first and second wedges, a clamping block, a support base and a linear drive device; the bottom of the clamping block is matched with a moving pair at the bottom of the support base, and the clamping block is moved along the moving pair through the linear drive device; the first wedge is moved along a direction perpendicular to the moving direction of the clamping block during the movement of the clamping block along the moving pair; the two second wedges are moved towards each other along a direction perpendicular to the moving direction of the clamping block during the movement of the clamping block along the moving pair; the workpiece to be processed is placed between the first and second wedges, and the workpiece to be processed is clamped during the movement of the clamping block along the moving pair. The application can effectively avoid the welding defect problem caused by the workpiece clamping device in the linear friction welding process.

Description

Technical Field

[0001] This invention relates to the field of linear friction welding technology, and more specifically to a linear friction welding device and its control method for cuboid workpieces. Background Technology

[0002] Linear friction welding is a solid-state joining technology that produces reliable weld joints with low manufacturing and operating costs. It can weld dissimilar metals and non-rotating bodies. Linear friction welding equipment primarily uses an electro-hydraulic servo system to apply linear reciprocating motion and upsetting pressure to the contact surfaces of two workpieces, generating frictional heat that softens, deforms, flows, and recrystallizes the material in the contact area, thus completing the weld. Poorly designed clamping devices can lead to difficulty in aligning the initial position of the weld joint, resulting in defects such as misalignment, irregular appearance, and uneven heating of the weld zone. Existing technology proposes a linear friction welding fixture, which mainly constrains the vibration direction and apex direction of a cuboid workpiece through upper and lower clamps and channel blocks. However, it lacks corresponding clamping devices on the left and right sides of the cuboid workpiece. Existing technology also discloses a method for fixing parts suitable for linear friction welding. While this fixture effectively constrains the left and right sides of the workpiece, it requires the design of multiple spherical protrusions, making machining complex. When neither the electro-hydraulic vibration system nor the electro-hydraulic upsetting system is in operation, the vibrating workpiece and the upsetting workpiece are perfectly aligned in their initial state. When the electro-hydraulic vibration system starts operating, ideally, the vibrating workpiece will experience a certain amount of vertical movement, while the upsetting workpiece will be subjected to an axial upsetting force from the electro-hydraulic upsetting system. Under the action of the fixture, the upsetting workpiece will not move vertically. Ideally, its vertical position will remain constant over time. In reality, however, the upsetting workpiece will experience a significant frictional force F in the vertical direction. f Due to the effect of this, the upsetting workpiece will inevitably move up and down in the vertical direction.

[0003] The vertical movement of the upsetting workpiece is due to insufficient clamping force of the fixture. However, if the clamping force is too large, the plowing effect cannot be formed, making it difficult to remove the material from the center of the weldment. If the clamping force is too small, the amplitude of the vertical movement of the upsetting workpiece will be increased, resulting in insufficient welding heat and affecting the mechanical properties and axial dimensional accuracy of the weldment joint. Therefore, it is necessary to control the clamping force reasonably.

[0004] Linear friction welding equipment primarily applies loads to the contact surfaces of vibrating and upsetting workpieces through electro-hydraulic excitation and upsetting systems. This causes the contact surface materials to soften, deform, flow, and recrystallize, thereby completing the welding process. Traditional linear friction welding fixtures mainly apply clamping force in the direction of vibration of the workpiece. However, the lack of effective clamping measures on both sides of the workpiece easily leads to misalignment between the vibrating and upsetting workpieces. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a linear friction welding device and its control method for cuboid workpieces. The device utilizes a groove within a clamping block, the top surface of which engages with the wedge surface of a first wedge. During the movement of the clamping block along the sliding joint, the first wedge moves in a direction perpendicular to the clamping block's movement. The sides of the groove engage with the wedge surfaces of second wedges, causing the two second wedges on either side to move towards each other in a direction perpendicular to the clamping block's movement. The workpiece to be processed is placed between the first and second wedges, and is clamped during the movement of the clamping block along the sliding joint. The two types of wedges simultaneously apply vertical and lateral clamping forces to the cuboid workpiece. The control method for the linear friction welding device for cuboid workpieces proposed in this invention effectively avoids welding defects caused by the workpiece clamping device during linear friction welding.

[0006] The present invention achieves the above-mentioned technical objectives through the following technical means.

[0007] A linear friction welding device for cuboid workpieces includes an electro-hydraulic excitation system, an electro-hydraulic upsetting system, and a clamping force control center;

[0008] The electro-hydraulic vibration system and the electro-hydraulic upsetting system are respectively equipped with clamping devices for clamping the workpiece to be processed; the clamping device includes a first wedge block and a second wedge block, a clamping block, a support base and a linear drive device.

[0009] The bottom of the clamping block engages with the bottom sliding joint of the support base. Slider blocks are provided on both sides of the clamping block. The sliders are located in the fourth groove on the side of the support base. The sliders are connected to a linear drive device, which moves the clamping block along the sliding joint.

[0010] The clamping block has a groove, the top surface of which engages with the wedge surface of the first wedge, causing the first wedge to move perpendicular to the direction of movement of the clamping block as the clamping block moves along the sliding joint. The sides of the groove engage with the wedge surfaces of the second wedges, causing the second wedges on both sides to move towards each other perpendicular to the direction of movement of the clamping block as the clamping block moves along the sliding joint. The workpiece to be processed is placed between the first and second wedges, and the workpiece is clamped as the clamping block moves along the sliding joint. The clamping force control center is used to adjust the clamping force of the clamping device.

[0011] Furthermore, the groove of the clamping block includes a first inclined surface and two second inclined surfaces. The top surface of the groove is the first inclined surface, and the two sides of the groove are respectively provided with symmetrical second inclined surfaces. The first inclined surface cooperates with the first wedge block; the two symmetrical second inclined surfaces cooperate with the second wedge blocks respectively.

[0012] Furthermore, the first wedge has a third inclined surface on its upper part, which contacts the first inclined surface, and the height of the third inclined surface decreases along the clamping direction of the clamping block; the first wedge is connected to the support base sliding pair.

[0013] Furthermore, a fourth inclined surface is provided on one side of the second wedge block, the fourth inclined surface is in contact with the second inclined surface, and the width of the third inclined surface decreases along the clamping direction of the clamping block; the second wedge block is connected to the sliding pair of the support base.

[0014] Furthermore, it also includes an image device and a displacement sensor; the displacement sensor is used to detect the moving distance of the clamping device on the electro-hydraulic upsetting system; the image device is used to identify and feedback the offset between the workpiece to be processed clamped by the clamping device on the electro-hydraulic vibration system and the workpiece to be processed clamped by the clamping device on the electro-hydraulic upsetting system; the clamping force control center adjusts the clamping force of the clamping device according to the detection values ​​of the image device and the displacement sensor.

[0015] A control method for a linear friction welding device for a cuboid workpiece includes the following steps:

[0016] The electro-hydraulic excitation system is equipped with a first clamping device, which clamps the vibrating workpiece with an initial clamping force f0 and controls the electro-hydraulic excitation system to make the vibrating workpiece vibrate up and down.

[0017] The electro-hydraulic upsetting system is equipped with a second clamping device, which clamps the upsetting workpiece with an initial clamping force f0. The electro-hydraulic upsetting system is controlled to make the second clamping device feed axially. During the axial feeding process, when the displacement sensor detects that the axial shortening of the upsetting workpiece increases linearly for the first time within 1 second, this moment is defined as time t1. When the rate of change of the axial shortening fed back by the displacement sensor begins to decrease, this moment is defined as time t2.

[0018] The clamping force control center controls the linear drive device of the second clamping device to gradually increase the clamping force between time t1 and t2; after reaching time t2, the clamping force control center controls the linear drive device of the second clamping device to maintain the clamping force at time t2 until the vibrating workpiece and the upsetting workpiece complete the friction welding.

[0019] Furthermore, the clamping force control center controls the linear drive device of the second clamping device to increase the clamping force by 5% to 10% every Δt time interval between t1 and t2.

[0020] Furthermore, the interval Δt is 1 to 1.5 s.

[0021] The beneficial effects of this invention are as follows:

[0022] 1. The linear friction welding device for a cuboid workpiece according to the present invention comprises a groove in the clamping block, the top surface of the groove engaging with the wedge surface of a first wedge, causing the first wedge to move perpendicular to the moving direction of the clamping block during the movement of the clamping block along the sliding joint; the sides of the groove engaging with the wedge surfaces of second wedges, causing the second wedges on both sides to move towards each other perpendicular to the moving direction of the clamping block during the movement of the clamping block along the sliding joint; the workpiece to be processed is placed between the first and second wedges, and the workpiece to be processed is clamped during the movement of the clamping block along the sliding joint, thereby applying vertical and horizontal clamping forces to the cuboid workpiece simultaneously using the two wedges.

[0023] 2. The linear friction welding device for cuboid workpieces described in this invention, wherein the clamping force control center controls the linear drive device of the second clamping device to increase the clamping force by 5% to 10% every Δt time interval between t1 and t2, can effectively avoid welding defects caused by the workpiece clamping device during linear friction welding. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are some embodiments of the present invention. For those skilled in the art, it is obvious that other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the linear friction welding device for cuboid workpieces described in this invention.

[0026] Figure 2 This is a three-dimensional assembly drawing of the clamping device described in this invention.

[0027] Figure 3 This is a three-dimensional diagram of the linear clamping block described in this invention.

[0028] Figure 4 This is a three-dimensional view of the first wedge block described in this invention.

[0029] Figure 5 This is a diagram showing the position of the third inclined plane described in this invention.

[0030] Figure 6 This is a three-dimensional view of the second wedge block described in this invention.

[0031] Figure 7 This is a diagram showing the position of the fourth inclined plane described in this invention.

[0032] Figure 8 This is a three-dimensional view of the support base described in this invention.

[0033] Figure 9This is an assembly diagram showing the contact between the clamping block and the first wedge block according to the present invention.

[0034] Figure 10 This is an assembly diagram showing the contact between the clamping block and the second wedge block according to the present invention.

[0035] Figure 11 This is a side view of the clamping device of the present invention assembled.

[0036] Figure 12 for Figure 11 AA sectional view.

[0037] Figure 13 This is a front view of the clamping device assembly described in this invention.

[0038] Figure 14 for Figure 13 BB cross-sectional view.

[0039] Figure 15 The graph shows the clamping force as a function of time.

[0040] Figure 16 This is a graph showing the axial shortening of the upsetting workpiece as a function of time.

[0041] Figure 17 This is a flowchart of the control method described in this invention.

[0042] In the picture:

[0043] 1-Vibrating workpiece; 2-Upsetting workpiece; 3-Clamping block; 3A-First inclined plane; 3B-Vertical plane; 3C-Second inclined plane; 3D-Slider; 3E-Dovetail slider; 4-First wedge; 4A-First groove; 4B-Third inclined plane; 4C-Second groove; 5-Second wedge; 5A-Third groove; 5B-Fourth inclined plane; 6-Support base; 6A-Dovetail groove; 6B-Fourth groove; 6C-Longitudinal guide rail; 6D-Transverse guide rail; 7-Linear drive device; 7A-Piston rod; 8-Clamping device; 10-Displacement sensor; 11-High-speed camera; 12-Clamping force control center; 13-Electro-hydraulic vibration system; 14-Electro-hydraulic upsetting system; 15-Marking point. Detailed Implementation

[0044] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0045] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0046] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] like Figure 1 As shown, the linear friction welding device for cuboid workpieces of the present invention includes an electro-hydraulic vibration system 13, an electro-hydraulic upsetting system 14, and a clamping force control center 12; the electro-hydraulic vibration system 13 is provided with a first clamping device for clamping the vibrating workpiece 1, and the electro-hydraulic upsetting system 14 is provided with a second clamping device for clamping the upsetting workpiece 2; the first clamping device and the second clamping device have the same structure.

[0048] like Figure 2 As shown, the following description uses the first clamping device as an example. The first clamping device includes a first wedge 4, a second wedge 5, a clamping block 3, a support base 6, and a linear drive device 7.

[0049] like Figure 3 and Figure 8As shown, the clamping block 3 has a parallel dovetail-shaped slider 3E at its bottom, and the corresponding support base 6 has a dovetail groove 6A at its bottom. The dovetail-shaped slider 3E can be movably installed in the dovetail groove 6A, that is, the bottom of the clamping block 3 and the bottom of the support base 6 are in contact with a sliding joint. The clamping block 3 has sliders 3D on both sides, and the sliders 3D are located in the fourth groove 6B on the side of the support base 6. The sliders 3D are connected to the linear drive device 7, which moves the clamping block 3 along the sliding joint; the direction of movement of the sliding joint is defined as the X direction. The clamping block 3 has a groove, the top surface of which engages with the wedge surface of the first wedge block 4. During the movement of the clamping block 3 along the X direction, the first wedge block 4 moves along the Z direction, which is perpendicular to the X direction. The sides of the groove engage with the wedge surfaces of the second wedge blocks 5. During the movement of the clamping block 3 along the X direction, the two second wedge blocks 5 move towards each other along the Y direction, which is perpendicular to the X direction. The workpiece to be processed is placed between the first wedge block 4 and the second wedge block 5. During the movement of the clamping block 3 along the moving pair, the workpiece to be processed is clamped. The clamping force control center 12 is used to adjust the clamping force of the clamping device.

[0050] like Figure 3 As shown, the groove of the clamping block 3 includes a first inclined surface 3A, two vertical surfaces 3B, and two second inclined surfaces 3C. The top surface of the groove is the first inclined surface 3A, and the two sides of the groove are vertical surfaces 3B. The two vertical surfaces 3B are located on both sides of the first inclined surface 3A, and the two vertical surfaces 3B are parallel to each other. Each vertical surface 3B has a second inclined surface 3C at its bottom, and the two second inclined surfaces 3C are symmetrically arranged. Figure 9 , Figure 12 and Figure 13 As shown, the first inclined surface 3A mates with the first wedge block 4; as Figure 9 , Figure 10 , Figure 11 and Figure 14 As shown, the second inclined surface 3C, which is symmetrical on both sides, is engaged with the second wedge block 5.

[0051] like Figure 4 and Figure 5As shown, the first wedge 4 has a third inclined surface 4B on its upper part, which contacts the first inclined surface 3A. The height of the third inclined surface 4B decreases along the clamping direction of the clamping block 3, and the first inclined surface 3A and the third inclined surface 4B have the same inclination angle. The side of the first wedge 4 is a vertical surface, which is clearance-fitted with the two vertical surfaces 3B of the clamping block 3. The first wedge 4 is slidably connected to the support base 6. The first wedge 4 has two parallel grooves, the first groove 4A and the second groove 4C. The support base 6 has two longitudinal guide rails 6C, which are located in the first groove 4A, forming a sliding connection. The workpiece to be processed can be placed in the second groove 4C. To ensure that the workpiece to be processed can be clamped in the second groove 4C, the width of the second groove 4C is slightly larger than the width of the workpiece by 1-3 mm, and the sum of the heights of the second groove 4C and the second wedge 5 is less than the height of the workpiece to be processed.

[0052] like Figure 6 and Figure 7 As shown, the second wedge 5 has a fourth inclined surface 5B on one side, which contacts the second inclined surface 3C. The width of the third inclined surface 4B decreases along the clamping direction of the clamping block 3. The second wedge 5 is slidably connected to the support base 6. The first wedge 4 has a third groove 5A, and the support base 6 has two transverse guide rails 6D. The longitudinal guide rails 6D are located within the third groove 5A, forming a slidably connected pair. Figure 10 and Figure 14 As shown, two second wedges 5 are located on both sides of the groove of the clamping block 3. The fourth inclined surface 5B on one side of each of the two second wedges 5 contacts the two second inclined surfaces 3C respectively. During the movement of the clamping block 3 in the X direction, the second wedges 5 on both sides move towards each other in the Y direction. Figure 14 For example, the upper second wedge 5 moves downward along the Y direction, and the lower second wedge 5 moves upward along the Y direction, thus ensuring that the two second wedges 5 clamp the workpiece to be processed at the same time.

[0053] like Figure 8 As shown, the support base 6 consists of three vertical surfaces and a base. The two vertical surfaces are provided with a fourth groove 6B, and the base is provided with two dovetail grooves 6A. The slider 3D is slidably connected to the fourth groove 6B, and the dovetail slider 3E is slidably connected to the dovetail groove 6A. On the third vertical surface, there are two parallel longitudinal guide rails 6C and two transverse guide rails 6D located on the same straight line. The longitudinal guide rails 6C are slidably connected to the first groove 4A, and the two transverse guide rails 6D are respectively slidably connected to the third grooves 5A of the two second wedges 5.

[0054] like Figure 1As shown, the system also includes a high-speed camera 11 and a displacement sensor 10. The displacement sensor 10 is used to detect the moving distance of the clamping device on the electro-hydraulic upsetting system 14. The high-speed camera 11 is used to identify and feedback the offset between the vibrating workpiece 1 clamped by the clamping device on the electro-hydraulic vibration system 13 and the upsetting workpiece 2 clamped by the clamping device on the electro-hydraulic upsetting system 14. Marking points 15 are machined on one side of both the vibrating workpiece 1 and the upsetting workpiece 2. The high-speed camera 11 acquires the offset between the marking points 15 on the vibrating workpiece 1 and the upsetting workpiece 2. The clamping force control center 12 adjusts the clamping force of the clamping device on the electro-hydraulic upsetting system 14 according to the detection values ​​of the high-speed camera 11 and the displacement sensor 10.

[0055] like Figure 17 As shown, the control method for the linear friction welding device for cuboid workpieces according to the present invention includes the following steps:

[0056] The electro-hydraulic excitation system 13 is equipped with a first clamping device, which clamps the vibrating workpiece 1 with an initial clamping force f0 and controls the electro-hydraulic excitation system 13 to make the vibrating workpiece 1 vibrate up and down; the electro-hydraulic upsetting system 14 is equipped with a second clamping device, which clamps the upsetting workpiece 2 with an initial clamping force f0.

[0057] like Figure 16 As shown, the linear friction welding process is mainly divided into four stages: contact stage, transition stage, stabilization stage, and upsetting stage. The electro-hydraulic upsetting system 14 pushes the upsetting workpiece 2 towards the high-frequency vibrating workpiece 1 until the upsetting workpiece 2 contacts the vibrating workpiece 1. During this process, the axial shortening of the upsetting workpiece 2 remains constant. As the vibrating workpiece 1 and the upsetting workpiece 2 gradually come into complete contact, the friction force formed by the contact between the surfaces of the two workpieces to be welded begins to rapidly heat the material, and the local temperature reaches the temperature required for welding. At this time, the axial shortening of the upsetting workpiece 2 begins to change, but the change is unstable. This stage is the transition stage. As the material at the interface of the contact surface between the vibrating workpiece 1 and the upsetting workpiece 2 undergoes plastic deformation, the upsetting workpiece 2 shortens axially along the upsetting direction. During this stage, the welding interface is in a state of thermal equilibrium, which is the stabilization stage. The axial shortening of the weldment per unit time remains constant. When entering the upsetting process, the shortening of the weldment per unit time decreases instantaneously and then remains constant.

[0058] Throughout the entire operation, the clamping force of the first clamping device remains constant at f0, while the clamping force of the second clamping device needs to be gradually increased during the steady-state phase, specifically as follows:

[0059] The electro-hydraulic upsetting system 14 is controlled to make the second clamping device axially feed. During the axial feeding process, when the displacement sensor 10 detects that the axial shortening of the upsetting workpiece 2 increases linearly for the first time within 1 second, this moment is defined as time t1; when the rate of change of the axial shortening fed back by the displacement sensor 10 begins to decrease, this moment is defined as time t2.

[0060] The clamping force control center 12 controls the linear drive device 7 of the second clamping device to increase the clamping force by 5% to 10% every Δt time interval between t1 and t2, with the Δt time interval being 1 to 1.5s; after reaching t2, the clamping force control center 12 controls the linear drive device 7 of the second clamping device to maintain the clamping force at t2 until the vibrating workpiece 1 and the upsetting workpiece 2 complete the friction welding.

[0061] like Figure 15 As shown, at time t1, the clamping force control center 12 gradually increases the clamping force by 5% to 10% and maintains it for 1 to 1.5 seconds; in this embodiment, the clamping force increases three times between times t1 and t2, and calculated based on an increase of 10%, the clamping force at time t2 is 1.1. 3 f0.

[0062] The high-speed camera 11 can assist the clamping force control center 12 in determining whether t1 and t2 have been reached.

[0063] The magnitude of f0 can be determined using the high-speed camera 11. By processing the sample and using the video captured by the high-speed camera 11, the minimum amplitude of the vertical sinusoidal motion of the upsetting workpiece 2 during the stable phase can be determined by observing the number of pixels where the marker point 15 changes in the video, and the corresponding optimal clamping force F can be recorded. j When the amplitude of the swing of the upsetting workpiece 2 is the smallest, the frictional heat generated by the movement of the vibrating workpiece 1 is the largest and most stable.

[0064] Preferred clamping force f0: When the clamping force F... j Multiple clamping forces of 96% F are set in the vicinity. j 97% F j 98% F j 99% F j F j 101% F j 102% F j 103% F j 104% F j A constant clamping force linear friction welding test was conducted using different clamping forces to test the mechanical properties and axial dimensional accuracy of the linear friction welded specimens under different clamping forces. The clamping force f0 with the most stable weld performance was selected as the initial clamping force for the cuboid workpiece.

[0065] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0066] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A linear friction welding device for a cuboid workpiece, characterized in that, It includes an electro-hydraulic excitation system (13), an electro-hydraulic upsetting system (14), a clamping force control center (12), an image equipment device, and a displacement sensor (10). The electro-hydraulic excitation system (13) and the electro-hydraulic upsetting system (14) are respectively equipped with clamping devices for clamping the workpiece to be processed; the clamping device includes a first wedge (4) and a second wedge (5), a clamping block (3), a support base (6) and a linear drive device (7). The bottom of the clamping block (3) is engaged with the bottom sliding pair of the support base (6). The clamping block (3) is provided with sliders (3D) on both sides. The sliders (3D) are located in the fourth groove (6B) on the side of the support base (6). The sliders (3D) are connected to the linear drive device (7). The clamping block (3) is moved along the sliding pair by the linear drive device (7). The clamping block (3) has a groove, the top surface of which engages with the wedge surface of the first wedge (4). During the movement of the clamping block (3) along the sliding pair, the first wedge (4) moves in a direction perpendicular to the movement of the clamping block (3). The sides of the groove engage with the wedge surfaces of the second wedge (5). During the movement of the clamping block (3) along the sliding pair, the second wedges (5) on both sides move towards each other in a direction perpendicular to the movement of the clamping block (3). The workpiece to be processed is placed between the first wedge (4) and the second wedge (5). During the movement of the clamping block (3) along the sliding pair, the workpiece to be processed is clamped. The clamping force control center (12) is used to adjust the clamping force of the clamping device. The displacement sensor (10) is used to detect the moving distance of the clamping device on the electro-hydraulic upsetting system (14); the image device is used to identify and feedback the offset between the workpiece to be processed clamped by the clamping device on the electro-hydraulic vibration system (13) and the workpiece to be processed clamped by the clamping device on the electro-hydraulic upsetting system (14); the clamping force control center (12) adjusts the clamping force of the clamping device on the electro-hydraulic upsetting system (14) according to the detection values ​​of the image device and the displacement sensor (10).

2. The linear friction welding device for a cuboid workpiece according to claim 1, characterized in that, The groove of the clamping block (3) includes a first inclined surface (3A) and two second inclined surfaces (3C). The top surface of the groove is the first inclined surface (3A), and the two sides of the groove are respectively provided with second inclined surfaces (3C). The first inclined surface (3A) cooperates with the first wedge (4); the two sides of the second inclined surface (3C) are respectively cooperated with the second wedge (5).

3. The linear friction welding device for a cuboid workpiece according to claim 2, characterized in that, The first wedge (4) has a third inclined surface (4B) on its upper part. The third inclined surface (4B) is in contact with the first inclined surface (3A). The height of the third inclined surface (4B) decreases along the clamping direction of the clamping block (3). The first wedge (4) is connected to the support base (6) in a sliding pair.

4. The linear friction welding apparatus for cuboid workpieces according to claim 3, characterized in that, The second wedge (5) has a fourth inclined surface (5B) on one side, which is in contact with the second inclined surface (3C). The width of the third inclined surface (4B) decreases along the clamping direction of the clamping block (3). The second wedge (5) is connected to the support base (6) in a sliding pair.

5. A control method for a linear friction welding apparatus for a cuboid workpiece according to claim 1, characterized in that, Includes the following steps: The electro-hydraulic excitation system (13) is provided with a first clamping device. The first clamping device clamps the vibrating workpiece (1) with an initial clamping force f0 and controls the electro-hydraulic excitation system (13) to make the vibrating workpiece (1) vibrate up and down. The electro-hydraulic upsetting system (14) is equipped with a second clamping device, which clamps the upsetting workpiece (2) with an initial clamping force f0. The electro-hydraulic upsetting system (14) is controlled to make the second clamping device feed axially. During the axial feeding process, when the displacement sensor (10) detects that the axial shortening of the upsetting workpiece (2) increases linearly for the first time within 1 second, this moment is defined as time t1. When the rate of change of the axial shortening fed back by the displacement sensor (10) begins to decrease, this moment is defined as time t2. The clamping force control center (12) controls the linear drive device (7) of the second clamping device to gradually increase the clamping force between time t1 and t2; after reaching time t2, the clamping force control center (12) controls the linear drive device (7) of the second clamping device to maintain the clamping force at time t2 until the vibrating workpiece (1) and the upsetting workpiece (2) complete the friction welding.

6. The control method for the linear friction welding device for a cuboid workpiece according to claim 5, characterized in that, The clamping force control center (12) controls the linear drive device (7) of the second clamping device to increase the clamping force by 5% to 10% every Δt time interval between t1 and t2.

7. The control method for the linear friction welding device for a cuboid workpiece according to claim 6, characterized in that, The time interval Δt is 1~1.5s.

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