An aluminum alloy casting machining fixture apparatus for aerospace

Abstract

The application relates to the technical field of mechanical hand auxiliary tooling, and particularly discloses an aluminum alloy casting machining clamp device for aerospace, which belongs to an auxiliary device cooperating with a mechanical hand and comprises a connecting frame, a supporting piece, at least two clamping jaws and a driving piece one; the clamping jaw comprises a frame, two groups of symmetrical swing arm groups, a supporting shaft, a clamping piece and a tension frame; the two swing arm groups can be synchronously opened and closed; the clamping jaw is internally provided with an adjusting frame, the adjusting frame is drivingly connected with the tension frame and the two swing arm groups, and integrated synchronous adjustment of clamping opening and tension is realized; through the comprehensive means of self-adaptive dispersion clamping pressure and synchronous adjustment of opening and tension of the clamping piece, the technical problem that extrusion deformation and residual stress are easily generated when a traditional rigid clamp clamps a thin-walled high-temperature aluminum alloy casting is solved.

Description

Technical Field

[0001] This invention relates to the field of tooling technology for robotic arms, and more particularly to a fixture for machining aluminum alloy castings for aerospace applications. Background Technology

[0002] Thin-walled aluminum alloy castings are widely used in the aerospace field due to their lightweight and high specific strength, and are core structural components of high-end equipment.

[0003] These components typically have wall thicknesses ranging from 0.5 mm to 2 mm. They are complex in structure, have poor rigidity and low hardness. The processing quality directly affects the service performance of the equipment, and the dimensional accuracy requirements are extremely high. If the clamping deformation exceeds the tolerance, the part will be scrapped.

[0004] In processing and transfer procedures, robotic arms are commonly used for gripping operations.

[0005] However, most existing robotic arm end effectors are rigid gripping structures, which rely on pressure plates or rigid grippers to apply localized clamping force for fixation, resulting in significant drawbacks: Firstly, thin-walled castings have weak rigidity, and traditional rigid fixtures concentrate the clamping force. Thin-walled areas are prone to extrusion indentation and elastic deformation. Springback and warping after processing and transportation can easily cause dimensional deviations and even irreversible plastic deformation, which is the primary reason for part scrap.

[0006] Secondly, aluminum alloy castings are produced at high temperatures after casting and heat treatment, resulting in rapid heat conduction and uneven temperature distribution. When rigid grippers clamp locally, the clamping force and thermal expansion combine, causing a sharp increase in stress in the clamping area. Furthermore, the yield strength of aluminum alloy decreases at high temperatures, weakening the deformation resistance of thin-walled areas. This thermo-mechanical coupling not only exacerbates deformation but also introduces additional residual stress, which can easily lead to workpiece distortion during subsequent release. Summary of the Invention

[0007] The purpose of this invention is to solve the above-mentioned problems by providing a fixture for machining aluminum alloy castings for aerospace applications.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows: a fixture for machining aluminum alloy castings for aerospace applications, comprising a guide frame and a robotic arm that moves along the guide frame, wherein the robotic arm includes: Connecting bracket, used for moving connection with guide frame; The support component is floatingly mounted on the connecting frame in a direction perpendicular to the connecting frame, and is used to press and support the top of the workpiece to be processed; The gripper, having at least two spaced around the support member, includes a frame, two sets of swing arms symmetrically arranged on the frame, each swing arm set including two swing arms spaced apart along the direction, two support shafts spaced apart between the two swing arms starting from the end away from the frame, a clamping member sequentially wound around the support shafts, and a tension frame that applies tension force to the clamping member. Drive component one is located between the frame and the connecting frame, and is used to drive the frame to move in the direction of approaching and moving away from the support component; The clamping member has a clamping surface on the side away from the frame, and the two swing arm assemblies are configured to move synchronously in the directions of approach and distance.

[0009] The aluminum alloy casting processing fixture equipment disclosed in this invention has the following advantages compared with the prior art: by decomposing the concentrated point load into a large number of tiny uniform contact points through the grid-type surface contact clamping structure, the unit clamping pressure is greatly reduced, fundamentally avoiding clamping deformation, extrusion indentation and springback of thin-walled castings, and effectively ensuring the dimensional accuracy of thin-walled aluminum alloy castings. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the overall structure of an aluminum alloy casting machining fixture for aerospace applications according to the present invention.

[0011] Figure 2 This is a schematic diagram of the robotic arm in this invention.

[0012] Figure 3 This is a side view of the robotic arm in this invention.

[0013] Figure 4 This is a schematic diagram of the robot arm's structure from below in this invention.

[0014] Figure 5 This is a partial structural diagram of the connecting frame in this invention.

[0015] Figure 6 This is a schematic diagram of the linkage component in the present invention. Figure 1 .

[0016] Figure 7 This is a schematic diagram of the linkage component in the present invention. Figure 2 .

[0017] Figure 8 This is a schematic diagram of the gripper structure in the present invention. Figure 1 .

[0018] Figure 9 for Figure 8 The diagram shows a partially enlarged structural schematic at point A in this invention.

[0019] Figure 10 This is a schematic diagram of the gripper structure in the present invention. Figure 2 .

[0020] Figure 11 This is a top view of the gripper structure in this invention.

[0021] Figure 12This is a cross-sectional view of the gripper structure in this invention.

[0022] Figure 13 This is a schematic diagram of the component change path structure of the gripper during the workpiece clamping process in this invention.

[0023] Figure 14 This is a schematic diagram of the change in the state of the gripper when it opens in this invention.

[0024] Figure 15 This is a schematic diagram of the gripper in use in this invention.

[0025] In the diagram: 1. Connecting frame; 10. Connecting flange; 11. Guide rail one; 2. Rigid arm; 20. Guide component one; 21. Drive component one; 22. Mounting plate; 220. Tie rod; 23. Sliding component one; 3. Support component; 3a. Servo motor; 30. Sliding component two; 31. Floating component; 32. Linkage component; 320. Guide hole; 33. Connecting rod; 34. Compression spring one; 4. Gripper; 40. Frame; 41. Swing arm; 4 10. Gear shaft one; 411. Gear shaft two; 42. Support shaft one; 43. Support shaft two; 430. Rotating component; 44. Clamping component; 440. Mounting base; 45. Clamping shaft; 46. Tensioning frame; 460. Compression spring two; 461. Guide rod; 462. Tensioning roller; 47. Adjusting frame; 470. Guide rail two; 471. Connecting plate; 472. Rack; 48. Driving component two; 5. Guide frame; 6. Sliding frame. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings. The drawings are simplified schematic diagrams, illustrating only the basic structure of the invention in a schematic manner, and therefore only show the components relevant to the invention.

[0027] This invention provides a fixture for machining aluminum alloy castings for aerospace applications, referenced. Figures 1 to 15 The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0028] Example 1 like Figures 1 to 4 As shown, the aluminum alloy casting machining fixture equipment for aerospace applications provided by the present invention includes a guide frame 5 and a robotic arm that moves along the guide frame 5. The guide frame 5 preferably adopts an I-beam rail structure. The robotic arm is suspended below the guide frame 5 via a sliding frame 6 and can reciprocate along the guide frame 5 to achieve automated transfer of workpieces.

[0029] The robotic arm includes a connecting frame 1, a support component 3, a gripper 4, and a drive component 21. The connecting frame 1 adopts a horizontally arranged rigid tubular structure, with a connecting flange 10 fixedly installed in the middle of its top surface. The connecting flange 10 enables detachable docking with the sliding frame 6, allowing the entire robotic arm to be stably mounted under the guide frame 5 and move synchronously with the sliding frame 6.

[0030] The support member 3 is floatingly positioned on the connecting frame 1 in a direction perpendicular to the connecting frame 1 (i.e., vertical direction). In one specific embodiment, a guide hole 320 or a guide groove structure (not shown in the figure) can be provided in the middle area of ​​the bottom of the connecting frame 1. The top of the support member 3 is provided with a guide post (not shown in the figure) that mates with the guide hole 320, allowing the support member 3 to float within a certain range in the vertical direction. The bottom surface of the support member 3 is a horizontal and flat surface, used to apply a pressing and supporting force to the top of the workpiece to be processed, ensuring the stability of the workpiece during clamping and transfer.

[0031] At least two grippers 4 are spaced apart around the support member 3. In this embodiment, two grippers 4 are symmetrically arranged as an example, but the invention is not limited to this, and three or more grippers 4 can be provided according to actual working conditions. Each gripper 4 includes a frame 40, two sets of swing arms symmetrically arranged on the frame 40, a support shaft, a clamping member 44, and a tensioning frame 46. The frame 40 preferably adopts a double-layer plate structure, including an upper plate and a lower plate arranged at intervals along the vertical direction, and the two plates are fixedly connected by connecting columns to form a rigid whole. Each swing arm group includes two swing arms 41 spaced apart along direction one (i.e., the vertical direction). The two swing arms 41 are respectively rotatably engaged with the upper plate and the lower plate of the frame 40 through a rotating shaft, so that the two sets of swing arms can swing relative to the frame 40. Each swing arm group also includes two support shafts spaced apart between the two swing arms 41 from the end away from the frame 40, namely support shaft two 43 near the end of the swing arm 41 and support shaft one 42 located in the middle area of ​​the swing arm 41. The clamping member 44 is wound around four support shafts to form an annular clamping working surface. The tensioning frame 46 is disposed inside the frame 40 and is used to apply tension to the clamping member 44 to ensure that the clamping member 44 always maintains appropriate tension to stably clamp the workpiece.

[0032] A drive component 21 is positioned between the frame 40 and the connecting frame 1 to drive the frame 40 to move towards and away from the support member 3. The drive component 21 is preferably a double-acting cylinder, with the cylinder body fixedly connected to the connecting frame 1 and the piston rod fixedly connected to the frame 40. When the drive component 21 extends, the frame 40 moves away from the support member 3, and the grippers 4 open to release the workpiece; when the drive component 21 retracts, the frame 40 moves towards the support member 3, and the grippers 4 close to hold the workpiece. The two sets of swing arms are configured to move synchronously in the directions of approach and distance, ensuring that the center position of the workpiece remains constant during clamping and avoiding clamping errors caused by clamping eccentricity.

[0033] In this embodiment, the robot arm's flexible movement within space is achieved through the cooperation of the connecting frame 1 and the guide frame 5. The floating configuration of the support member 3 allows for adaptive adjustment based on the workpiece height when applying downward pressure to the top of the workpiece, avoiding damage to thin-walled workpieces caused by rigid impacts. The surrounding arrangement of two or more grippers 4 provides a basis for multi-point uniform clamping, while the symmetrical arrangement and synchronous movement design of the two sets of swing arms in each gripper 4 ensures a uniform distribution of clamping force in the circumferential direction of the workpiece.

[0034] Example 2 Based on the above implementation methods, such as Figure 8 , Figure 10 , Figure 11 As shown, each support shaft is provided with a rotating component 430 that rotatably engages with the swing arm 41, and the clamping component 44 is wound around the rotating component 430.

[0035] The rotating component 430 is rotatably engaged with the swing arm 41. Specifically, the engagement is as follows: support shaft 1 42 and support shaft 2 43 are detachably and fixedly connected to the swing arm 41, and the rotating component 430 is rotatably engaged with the support shafts. Alternatively, both support shaft 1 42 and support shaft 2 43 are rotatably engaged with the swing arm 41, while the rotating component 430 is detachably and fixedly connected to the support shafts.

[0036] In this embodiment, by providing a rotating component 430 on the support shaft, the clamping component 44 and the rotating component 430 rotate and cooperate with each other during the opening and closing of the swing arm assembly, ensuring smooth opening and closing of the swing arm assembly and preventing wear caused by relative sliding between the clamping component 44 and the support shaft. At the same time, the rotating component 430 ensures that the clamping component 44 maintains an appropriate tension under the action of the tensioning frame 46, ensuring the stability and reliability of clamping.

[0037] Example 3 Based on the above implementation methods, such as Figures 8 to 12 As shown, the rotating member 430 includes at least two members spaced apart along the axial direction of the support shaft.

[0038] Accordingly, the clamping member 44 is a strip-shaped structure, including at least two that are arranged in a one-to-one correspondence with the rotating member 430. Along the length direction of the clamping member 44, a plurality of mounting seats 440 are evenly spaced on the clamping member 44, and clamping shafts 45 are evenly spaced between adjacent clamping members 44, with both ends of the clamping shafts 45 connected to the mounting seats 440.

[0039] In this embodiment, two rotating members 430 and two strip-shaped clamping members 44 are used as examples for explanation. The two rotating members 430 are respectively positioned at the upper and lower ends of the support shaft, and the two annular strip-shaped clamping members 44 are respectively wound around the upper and lower rotating members 430, forming a parallel double-layer clamping structure. Along the length of the clamping members 44, a mounting seat 440 is provided at predetermined intervals. This mounting seat 440 is used to fix and connect the vertically arranged clamping shaft 45. The two ends of the clamping shaft 45 are rotatably engaged with the mounting seats 440 at corresponding positions on the upper and lower clamping members 44, so that multiple clamping shafts 45 are evenly arranged along the circumference of the clamping members 44, forming a clamping working surface similar to a chain grate or grid.

[0040] In this embodiment, by setting up a cooperative structure of at least two layers of clamping members 44 with multiple mounting seats 440 and clamping shafts 45, when clamping the workpiece, the clamping force originally provided by a single clamping member 44 through line contact or small area contact is decomposed into multiple tiny uniform contact points formed by multiple clamping shafts 45 simultaneously adhering to the outer wall of the workpiece. This structure significantly increases the contact area between the clamping members 44 and the workpiece, transforming the concentrated point load of the traditional rigid jaws 4 into a distributed surface load, greatly reducing the clamping pressure per unit area. For thin-walled aluminum alloy castings with a wall thickness of only 0.5 mm to 2 mm, this structure can effectively avoid extrusion indentation and elastic deformation caused by clamping force, fundamentally solving the industry pain point of clamping deformation of thin-walled parts. At the same time, the grid-like clamping structure can effectively conform to the workpiece surface, with no suspended clamping areas, significantly improving clamping stability.

[0041] Example 5 Based on the above embodiments, as a preferred embodiment, the support shaft and the mounting base 440 are rotatably coupled.

[0042] Specifically, the mounting base 440 is fixedly mounted on the clamping member 44, and the end of the support shaft is inserted into the shaft hole on the mounting base 440. A rolling bearing or a sliding bearing is provided between the end of the support shaft and the shaft hole of the mounting base 440, allowing the support shaft to rotate freely within the mounting base 440. The clamping shaft 45 is vertically mounted between the upper and lower mounting bases 440, and both ends of the clamping shaft 45 are rotatably engaged with the upper and lower mounting bases 440, respectively.

[0043] In this embodiment, the rotational fit design between the support shaft and the mounting base 440 ensures that all moving parts of the entire clamping member 44 can rotate freely to release deformation displacement during the movement of the swing arm 41 group and the adjustment of the tension frame 46. When the swing arm 41 group retracts or opens, the support shaft rotates relative to the mounting base 440, effectively avoiding structural jamming. This design ensures that the clamping member 44 is always in a smooth driven rotational state throughout the entire working process, and will not be subjected to continuous local pressure due to structural jamming, thereby ensuring the uniformity of circumferential force on the thin-walled casting and effectively suppressing the generation of plastic deformation; at the same time, it can be adapted to the support member 3, which can rotate around its own axis. The support member 3 is driven by the servo motor 3a to apply driving force to the clamped workpiece, driving the workpiece to rotate slowly around its own axis. At this time, the rotatable clamping shaft 45 allows the workpiece to rotate around its own axis. The rotational clamping method can better suppress local deformation caused by prolonged local clamping of the workpiece.

[0044] Based on the above embodiments, as a specific implementation, the clamping member 44 can be a chain, and correspondingly, the rotating member 430 is a sprocket. The chain and sprocket meshing transmission method has the advantages of high load-bearing capacity, precise transmission, and good high-temperature resistance, and is particularly suitable for the transfer and clamping of large-sized high-temperature aluminum alloy castings. The chain structure can withstand large tensile loads and maintain good mechanical properties in high-temperature environments, and the meshing of the sprocket and chain can precisely maintain the motion synchronization of the clamping member 44.

[0045] As an alternative implementation, the clamping member 44 can be a synchronous belt, and correspondingly, the rotating member 430 can be a synchronous pulley. The engagement of the synchronous belt and pulley offers advantages such as greater flexibility and no hard indentations, resulting in a gentler contact with the workpiece surface during clamping. This is particularly suitable for precision machining of ultra-thin castings with wall thicknesses of only 0.5 mm to 1 mm. The outer surface of the synchronous belt can be coated with a high-temperature resistant layer as needed to further improve clamping contact performance.

[0046] In this embodiment, the interchangeable modular design of the chain and the synchronous belt allows the same fixture equipment to flexibly select the most suitable clamping component 44 type according to the material, wall thickness, temperature, and processing requirements of different workpieces. Both types of clamping components 44 are compatible with the integrated synchronous amplitude and tension adjustment structure of the adjustment frame 47, eliminating the need to modify the adjustment transmission mechanism when switching tooling, greatly enhancing the versatility and adaptability of the equipment and reducing the user's tooling costs.

[0047] Example 6 Based on the above implementation methods, such as Figure 8 , Figure 9As shown, the robotic arm also includes an adjustment frame 47 and a second drive component 48. The adjustment frame 47 is mounted on the frame 40, floating along a first direction, located on the side of the tensioning frame 46 away from the clamping component 44, and is horizontally positioned in the first direction and located on the symmetrical plane of the two swing arms 41. Specifically, horizontal guide rails 470 are provided on both plates of the frame 40, and a third sliding component (not shown) is slidably fitted onto the guide rails 470. Connecting plates 471 are provided at both ends of the adjustment frame 47, and the connecting plates 471 are connected to the third sliding component, allowing the adjustment frame 47 to float and move along the guide rails 470 in the first direction. The adjustment frame 47 is preferably a vertically mounted plate-shaped component.

[0048] Drive component 48 is used to drive the adjusting frame 47 and provide a floating force to the adjusting frame 47. Drive component 48 is preferably a double-acting cylinder or an electric telescopic rod, with its cylinder end fixedly connected to the frame 40 and its telescopic end fixedly connected to the adjusting frame 47. By controlling the extension and retraction of drive component 48, the position of the adjusting frame 47 within the frame 40 can be precisely adjusted.

[0049] The tensioning frame 46 is connected to the adjusting frame 47, and the adjusting frame 47 is also driven by the two swing arm assemblies. Specifically, the guide rod 461 of the tensioning frame 46 passes through the guide hole on the adjusting frame 47 and can slide within the guide hole. A spring is sleeved on the guide rod 461, giving the tensioning frame 46 an elastic floating capability relative to the adjusting frame 47. The adjusting frame 47 is driven by the two swing arm assemblies through a rack and pinion mechanism 472.

[0050] In this embodiment, the floating configuration of the adjusting frame 47 enables the linkage of two key functions: when the adjusting frame 47 floats away from the clamping member 44, the two swing arm assemblies are linked to swing away from each other, and the gripper 4 opens to accommodate workpieces with larger outer diameters; when the adjusting frame 47 floats towards the clamping member 44, the two swing arm assemblies are linked to swing towards each other, and the gripper 4 closes to clamp workpieces with smaller outer diameters.

[0051] Simultaneously, the displacement of the adjusting frame 47 synchronously drives the tensioning frame 46 to move, causing the tension of the clamping member 44 to adaptively adjust with the change of the clamping diameter. This structure achieves integrated synchronous adjustment of clamping opening and clamping tension, requiring only one set of drive components to complete both adjustment actions simultaneously, eliminating the need for two independent adjustment power systems, simplifying the equipment structure, reducing manufacturing costs, and improving the synchronicity and consistency of adjustment.

[0052] As a specific implementation method, such as Figures 10 to 13As shown, the swing arm assembly is connected to a gear shaft 410, which is rotatably connected to the frame 40. The gear shaft 410 drives a gear shaft 411. Specifically, a gear shaft 410 is fixedly connected to the root of each swing arm 41 (i.e., the end closest to the frame 40), and each gear shaft 410 drives a gear shaft 411. The gear shaft 411 also rotatably engages with the upper and lower plates of the frame 40.

[0053] The adjusting frame 47 is equipped with a rack 472 that is driven and connected to the two gear shafts 411. Specifically, the rack 472 is mounted on the adjusting frame 47, and the extension direction of the rack 472 is consistent with the floating direction of the adjusting frame 47. The rack 472 meshes with the gears on the gear shaft 411. When the adjusting frame 47 floats in the first direction, the rack 472 drives the gear shaft 411 to rotate, which in turn drives the two sets of swing arms 41 to swing synchronously through the gear shaft 410.

[0054] In this embodiment, through the precise meshing transmission of gear shaft 410, gear shaft 411, and rack 472, when the driving component 48 drives the adjusting frame 47 to move back and forth, the racks 472 on both sides output power synchronously, and the gear shafts 411 and 410 on both sides rotate synchronously. The opening and closing speeds and opening and closing amplitudes of the two sets of swing arms 41 are completely consistent. This synchronous gear and rack transmission structure ensures that the clamping center always coincides with the rotation center of the support component 3, and avoids the problem of eccentric force that causes one side to be clamped too tightly and the other side to be loose, thus ensuring the micron-level clamping accuracy of the aerospace thin-walled casting. At the same time, gear transmission has the advantages of precise transmission, strong load-bearing capacity, and long service life, which can meet the stringent requirements of equipment reliability and repeatability in the aerospace manufacturing field.

[0055] In one specific implementation, a second guide rail 470 is provided on the frame 40, and a connecting plate 471 is slidably fitted onto the second guide rail 470. The connecting plate 471 is connected to the adjusting frame 47, and the rack 472 includes two racks respectively disposed on both sides of the connecting plate 471. In this embodiment, the cooperation between the second guide rail 470 and the sliding member constrains the adjusting frame 47 to move only in a straight line along the plane of symmetry, effectively eliminating the vertical and horizontal offset of the adjusting frame 47 during the movement, ensuring the straightness and accuracy of the transmission. The two racks 472 are symmetrically arranged on both sides of the connecting plate 471, respectively meshing with the transmission structure of the gear shafts 411 on both sides, so that the force on both sides is balanced and there is no single-sided transmission backlash difference. When adjusting the opening of the swing arm 41 and the position of the tensioning frame 46, the movement on both sides is completely synchronized, and there is no transmission offset under long-term high-temperature continuous operation, and the clamping force is uniform. This structural design significantly improves the transmission accuracy retention capability and service life of the equipment under long-term continuous operation conditions. In this embodiment, the second driving component 48 can be a drive motor, and the output shaft of the drive motor is provided with a gear that meshes with the rack 472.

[0056] As a specific implementation method, such as Figure 12 As shown, the tensioning frame 46 includes a tensioning roller 462 that supports and cooperates with the clamping member 44, and a guide rod 461 that is connected to the tensioning roller 462 and guides and cooperates with the adjusting frame 47. One end of the guide rod 461 extending out of the adjusting frame 47 has a limiting surface. The tensioning roller 462 is disposed inside the clamping member 44, and its outer surface rolls in contact with the inner surface of the clamping member 44, applying an outward tensioning force to the clamping member 44. One end of the guide rod 461 is fixedly connected to the tensioning roller 462, and the other end passes through a guide hole opened on the adjusting frame 47 and extends out of the adjusting frame 47. The end of the guide rod 461 extending out of the adjusting frame 47 has an external thread, through which a locking nut is fitted. The end face of the locking nut forms a limiting surface.

[0057] A second compression spring 460 is sleeved on the guide rod 461, located between the tension roller 462 and the adjusting frame 47. When the limiting surface abuts against the adjusting frame 47, the second compression spring 460 is compressed, meaning it is always in a pre-compressed state. This pre-compression ensures that the second compression spring 460 always applies a pushing force towards the clamping member 44 to the tension roller 462, guaranteeing that the clamping member 44 maintains proper tension under any operating condition.

[0058] In this embodiment, as the driving component 48 moves the adjusting frame 47 back and forth and synchronously changes the opening of the swing arm 41, the tensioning roller 462 is always pressed against the middle section of the clamping component 44 under the elastic force of the compression spring 460. When the swing arm 41 retracts and the distance between the support shafts shortens, the tensioning frame 46 can move synchronously with the adjusting frame 47 to tension the clamping component 44. When the swing arm 41 opens, the tensioning frame 46 moves synchronously to release the clamping component 44. This structure allows the tensioning frame 46 to adaptively compensate for the displacement of the clamping component 44 according to its opening degree, so that a constant range of tension is applied when clamping the workpiece, and the clamping component 44 can maintain a constant range of tension force under various clamping diameters.

[0059] Example 6 This application provides a fixture device for machining aluminum alloy castings for aerospace applications, such as... Figures 5 to 7As shown, the robotic arm includes two symmetrically arranged grippers 4, a guide rail 11, linkages 32, compression springs 34, a floating component 31, a servo motor 3a, and a drive component 21. The guide rail 11 is mounted on the connecting frame 1 and extends horizontally. Two linkages 32 are symmetrically arranged about the support component 3 and slide in a guide-sliding engagement with the guide rail 11. Each linkage 32 has a pull rod 220, one end of which is fixedly connected to the linkage 32, and the other end of which passes through a through hole in the other linkage 32 and slides in a sliding engagement with it. Compression springs 34 are correspondingly sleeved on the pull rods 220, with both ends abutting against the two linkages 32 respectively. The floating component 31 is located between the two linkages 32 and is connected to both linkages 32 by a connecting rod 33. The support component 3 is rotatably mounted on the floating component 31. The servo motor 3a is mounted on the floating component 31 and drives the support component 3. Each gripper 4 is connected to a drive component 21. The two drive components 21 are located on both sides of the two linkage components 32. The drive component 21 is connected to the end of the pull rod 220 that extends out of the other linkage component 32.

[0060] Specifically, a guide rail 11 is arranged laterally at the bottom of the connecting frame 1. A sliding member 23 and a sliding member 30 are symmetrically slidably fitted on the guide rail 11. A linkage member 32 is fixedly mounted on the sliding member 30. A through hole with a sliding bearing is provided on the linkage member 32, through which the pull rod 220 passes. A compression spring 34 is sleeved on the pull rod 220 and located between the two linkage members 32. A mounting plate 22 is fixedly mounted on the outer end of the pull rod 220. A drive member 21 (preferably a double-rod cylinder) is mounted on the sliding member 23, and its telescopic end is connected to the mounting plate 22. A guide member 20 is also provided on the upper part of the connecting frame 1. A rigid arm 2 is slidably fitted with the guide member 20, and the tail of the rigid arm 2 is connected to the telescopic end of the drive member 21. The two linkage members 32 are respectively connected to the floating member 31 through hinged rigid connecting rods 33. The lower ends of the connecting rods 33 are hinged together on the floating member 31, forming a connecting rod 33 drive structure. The floating component 31 is also equipped with a vertical guide rod (not shown in the figure) to achieve limit guidance. A servo motor 3a is mounted on the top surface of the floating component 31. The output shaft of the servo motor 3a is connected to the support component 3, which can rotate around its own axis.

[0061] In this embodiment, in the initial non-clamping state, the compression spring 34 pushes the linkage 32 outward under the action of elastic force until the sliding member 23 and the sliding member 30 abut against the limit position. When clamping is required, the drive member 21 drives the rigid arm 2 to move towards the workpiece. After the gripper 4 contacts the workpiece, the reverse force generated by the workpiece on the gripper 4 is transmitted to the mounting plate 22 through the rigid arm 2 and the drive member 21, pulling the linkage 32 on both sides inward and compressing the compression spring 34. The inward movement of the linkage 32 pulls down the floating member 31 synchronously through the linkage 33 mechanism, so that the support member 3 presses the top of the casting vertically downward. During the entire clamping process, the servo motor 3a drives the casting to rotate slowly. With the integrated synchronous amplitude adjustment and constant tension flexible clamping structure of the gripper 4, there is no long-term fixed high pressure area in the circumferential direction of the workpiece, effectively avoiding the local thermal stress concentration and residual stress generation. When the clamping operation is completed and the drive component 21 reverses its movement, the compression spring 34 releases its elastic potential energy to push the linkage component 32 back to its original position, and the support component 3 rises to release the workpiece. This compression spring buffer linkage structure achieves synchronous linkage between the clamping action and the top support action, eliminating the need for a separate drive source for the support component 3, simplifying the control system and reducing energy consumption. At the same time, the spring's buffering effect can also absorb the impact energy during the clamping process, preventing rigid impacts from damaging thin-walled workpieces.

[0062] Working principle This invention provides a fixture for machining aluminum alloy castings for aerospace applications, referenced. Figures 1 to 15 This device is applied to the automated loading, unloading, and transfer clamping of thin-walled, high-temperature cylindrical aluminum alloy castings, belonging to the field of robotic arm auxiliary tooling technology. The equipment consists of a guide rail, a sliding frame 6, and a lifting robotic arm. The robotic arm is based on a rigid connecting frame 1 with a top connecting flange 10. The connecting frame 1 is equipped with a guide rail 11, a guide component 20, and a spring linkage buffer assembly. A dual synchronous cylinder 21 drives the rigid arm 2 to move. When clamping the workpiece, it links and compresses the compression spring 34, pulling down the floating component 31 through the connecting rod 33, so that the servo-driven rotatable support component 3 presses down synchronously to clamp the top of the casting, achieving coordinated support and positioning of the top and side walls of the thin-walled cylindrical workpiece.

[0063] The gripper 4 adopts a double-layer plate frame structure 40, with an integrated adjustment frame 47 inside. The adjustment frame 47 is driven by the second drive component 48 to float along the second guide rail 470. Through the synchronous meshing of the gear shaft 411 by the racks 472 symmetrically arranged on both sides of the connecting plate 471, the power is transmitted to the two sets of swing arms through the first gear shaft 410, realizing the synchronous opening and closing movement of the two sets of swing arms 41. At the same time, the adjustment frame 47 and the tensioning frame 46 are connected by a guide rod 461. The guide rod 461 is fitted with a pre-compression spring 460, so that the opening adjustment of the swing arm 41 and the constant tension compensation of the clamping component 44 are completed synchronously, keeping the clamping component 44 in the optimal tension state at all times within the full opening range. The clamping component 44 adopts a double-layer ring structure of chain or synchronous belt, which is wound around the sprockets or synchronous belt pulleys installed at both ends of the support shaft. The clamping component 44 is evenly spaced with multiple vertical clamping shafts 45 in the circumferential direction to form a grid-like surface contact clamping working surface. This decomposes the point contact concentrated load of the traditional rigid gripper 4 into a large number of small uniform contact points. With the full rotational engagement between the support shaft and the mounting base 440, and between the clamping shafts 45 and the mounting base 440, all moving parts can rotate freely to release deformation displacement during the clamping process.

[0064] When clamping the workpiece, the drive component 21 drives the rigid arm 2 to move towards the workpiece. After the gripper 4 contacts the workpiece, the reaction force of the workpiece on the gripper 4 is transmitted to the mounting plate 22 through the rigid arm 2 and the drive component 21, pulling the linkage components 32 on both sides to compress the compression spring 34. At the same time, the connecting rod 33 pulls down the floating component 31 to press the support component 3 against the top of the casting. After clamping is completed, the servo motor 3a drives the support component 3 and the workpiece to rotate slowly at a set speed. The clamping component 44 rotates with the workpiece through the rotating component 430 to avoid static friction at a fixed point. The high-temperature resistant glass fiber silicone rubber composite layer covering the outer layer of the support shaft isolates the high-temperature blank from the metal structure. The whole structure uses clamping linkage pressing, workpiece rotation to balance stress, large-area grid-type flexible contact, and integrated synchronous amplitude adjustment and tension adjustment as core technologies to achieve uniform flexible clamping of the entire area for high-temperature thin-walled cylindrical parts in aerospace, fundamentally solving the defects of traditional rigid gripper 4 such as stress concentration, high-temperature thermal coupling deformation, extrusion springback of thin-walled parts, and residual stress generation.

[0065] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A fixture for machining aluminum alloy castings for aerospace applications, comprising a guide frame (5) and a robotic arm that moves along the guide frame (5), characterized in that, The robotic arm includes: Connecting frame (1) is used for motion connection with guide frame (5); The support (3) is floatingly disposed on the connecting frame (1) in a direction perpendicular to the connecting frame (1) and is used to press and support the top of the workpiece to be processed; The gripper (4) is arranged at least two around the support member (3), including a frame (40), two sets of swing arms symmetrically arranged on the frame (40), each swing arm assemblies including two swing arms (41) arranged at a distance along the direction, two support shafts arranged at a distance between the two swing arms (41) from the end away from the frame (40), a clamping member (44) arranged around the support shaft in sequence, and a tensioning frame that applies tension to the clamping member (44); A drive component (21) is disposed between the frame (40) and the connecting frame (1) for driving the frame (40) to move in the direction of approaching and moving away from the support component (3); The clamping member (44) has a clamping surface on the side away from the frame (40), and the two swing arm assemblies are configured to move synchronously in the directions of approach and distance.

2. The aerospace-grade aluminum alloy casting machining fixture equipment according to claim 1, characterized in that, Each of the support shafts is provided with a rotating component (430) that rotates with the swing arm (41), and the clamping component (44) is wound around the rotating component (430).

3. The aerospace-grade aluminum alloy casting machining fixture equipment according to claim 2, characterized in that, The rotating component (430) includes at least two components spaced apart along the axial direction of the support shaft; The clamping member (44) is a strip structure, including at least two that correspond one-to-one with the rotating member (430). Along the length direction, the clamping member (44) is provided with a plurality of mounting seats (440) at even intervals. Between two adjacent clamping members (44), clamping shafts (45) are provided at even intervals. The two ends of the clamping shafts (45) are connected to the mounting seats (440).

4. The aerospace-grade aluminum alloy casting machining fixture equipment according to claim 3, characterized in that, The clamping shaft (45) is rotatably engaged with the mounting base (440).

5. A fixture for machining aluminum alloy castings for aerospace applications according to claim 3, characterized in that, The clamping member (44) is a chain, and the rotating member (430) is a sprocket; Alternatively, the clamping member (44) may be a timing belt, and the rotating member (430) may be a timing pulley.

6. A fixture for machining aluminum alloy castings for aerospace applications according to claim 2, characterized in that, The gripper (4) also includes: The adjustment frame (47) is floating on the frame (40) along the first direction and is located on the side of the tensioning frame away from the clamping member (44). The first direction is located on the symmetrical plane of the two swing arm groups. Drive component 2 (48) is used to drive the adjustment frame (47) and provide a floating force to the adjustment frame (47); The tensioning frame is connected to the adjusting frame (47), and the adjusting frame (47) is driven to connect to the two swing arm assemblies; When the adjusting frame (47) floats away from the clamping member (44), the two swing arms swing away from each other; when the adjusting frame (47) floats closer to the clamping member (44), the two swing arms swing closer to each other.

7. A fixture for machining aluminum alloy castings for aerospace applications according to claim 6, characterized in that, The swing arm assembly is connected to a gear shaft one (410), which is rotatably connected to the frame (40), and the gear shaft one (410) is driven to connect to a gear shaft two (411). The adjusting frame (47) is provided with a rack (472) that is driven and connected to the two gear shafts (411).

8. A fixture for machining aluminum alloy castings for aerospace applications according to claim 7, characterized in that, The frame (40) is provided with a second guide rail (470), and a connecting plate (471) is slidably fitted on the second guide rail (470). The connecting plate (471) is connected to the adjusting frame (47). The rack (472) includes two racks respectively disposed on both sides of the connecting plate (471).

9. A fixture for machining aluminum alloy castings for aerospace applications according to claim 6, characterized in that, The tensioning frame includes a tensioning roller (462) that supports and cooperates with the clamping member (44), and a guide rod (461) that is connected to the tensioning roller (462) and cooperates with the adjusting frame (47). The end of the guide rod (461) that extends out of the adjusting frame (47) is provided with a limiting surface. Located between the tension roller (462) and the adjusting frame (47), a compression spring (460) is sleeved on the guide rod (461). When the limiting surface abuts against the adjusting frame (47), the compression spring (460) has a compression amount.

10. A fixture for machining aluminum alloy castings for aerospace applications according to claim 1, characterized in that, The robotic arm includes two symmetrically arranged grippers (4), and the robotic arm also includes: Guide rail 1 (11) is mounted on the connecting frame (1); The linkage (32) includes two symmetrically arranged about the support (3) and slidingly guided by the guide rail (11). Each linkage (32) is provided with a pull rod, and the other end of the pull rod passes through the other linkage (32). Compression spring 1 (34) is fitted on the pull rod in a one-to-one correspondence, and its two ends abut against the two linkage parts (32) respectively; The floating component (31) is located between the two linkage components (32) and is connected to both linkage components (32) by a connecting rod (33). The support component (3) is rotatably mounted on the floating component (31). A servo motor (3a) is mounted on a floating component (31) and driven by the support component (3); Each gripper (4) is connected to a drive component (21). The two drive components (21) are located on both sides of the two linkage components (32). The drive component (21) is connected to the end of the pull rod that extends out of the other linkage component (32).

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