Tensioning mechanism for processing thin-walled parts of an aircraft

Abstract

The utility model discloses a kind of tensioning mechanisms of aircraft thin-walled part processing, to solve the problem that traditional external clamping is prone to thin-walled part deformation. The mechanism includes processing table, arc-shaped tensioning limit block is equipped in upper side of processing table, and transmission assembly driven by hydraulic pressure is equipped in inside. Hydraulic rod pushes isosceles trapezoidal extrusion block to move, and the inclined plane is extruded triangular compression block on two sides simultaneously, converts one-way thrust into symmetrical horizontal component force, drives two arc-shaped tensioning limit blocks to move in opposite directions, and the radial expansion tensioning is carried out from the inside of the thin-walled part to be processed (such as paddle protection ring). Pressure sensor is equipped in mechanism for real-time monitoring and control tensioning force, to prevent workpiece damage. Arc-shaped tensioning limit block is detachable design, to facilitate the adaptation of different specifications workpiece. The utility model realizes the uniform, stable, non-destructive internal tensioning fixation of thin-walled part, and it is especially suitable for the processing of thin-walled workpiece such as unmanned aerial vehicle paddle protection ring.

Description

Technical Field

[0001] This utility model relates to the field of workpiece processing fixture technology for unmanned aerial vehicles (UAVs), specifically a tensioning mechanism for processing thin-walled parts of aircraft. Background Technology

[0002] Aircraft, especially drones, widely employ thin-walled components in their structure to achieve lightweight design goals. These thin-walled components, such as propeller guard rings, are typically made of engineering plastics like ABS and molded in one piece using an injection molding process. Their wall thickness is relatively thin, generally between 0.6mm and 1mm. During subsequent machining processes (such as trimming and drilling), these parts need to be stably clamped and fixed to ensure machining accuracy and prevent workpiece deformation or damage.

[0003] Existing workpiece clamping methods, such as common vises, primarily rely on applying clamping force externally. However, when applied to thin-walled parts with specific curved contours, such as blade protectors, traditional external clamping methods have significant drawbacks. First, the external clamping force acts directly on the outer surface of the thin-walled part, easily leading to workpiece crushing, deformation, or surface damage due to stress concentration. Second, because thin-walled parts have poor rigidity, vises struggle to provide uniform and reliable clamping force, making them prone to loosening or shifting during machining, severely impacting machining quality and safety.

[0004] Therefore, we propose a tensioning mechanism for machining thin-walled parts of aircraft. Utility Model Content

[0005] (a) Technical problems to be solved In response to the shortcomings of existing technologies, this utility model achieves stable and non-destructive tensioning and fixing of thin-walled aircraft components from the inside, fundamentally solving the technical problem that traditional external clamping easily leads to workpiece deformation.

[0006] (II) Technical Solution To achieve the above objectives, the technical solution adopted by this utility model is as follows: a tensioning mechanism for processing thin-walled parts of aircraft, including a processing table, on which grooves are formed on both the left and right sides of the upper outer surface of the processing table. An installation chamber is provided inside the processing table, and the grooves extend to the upper left and right sides of the installation chamber. A support rod passes through the grooves. A pressure sensor, a connecting arm, an isosceles trapezoidal extrusion block, a movable block, a triangular pressure block, a support arm, and a compression spring are arranged inside the installation chamber. Arc-shaped tensioning limit blocks are provided on the left and right sides of the upper part of the processing table. A connecting block is fixedly installed in the middle of the inner side of the arc-shaped tensioning limit block. The connecting block is fixed to the upper outer surface of the support rod by bolts. A hydraulic rod is installed in the middle of the outer surface of the front end of the machining table. One end of the piston rod of the hydraulic rod extends into the interior of the machining table and is fixedly connected to the middle of the outer surface of the front end of the connecting arm. First guide rings are fixedly installed on the left and right sides of the outer surface of the front end of the machining table. The first guide rings penetrate to the front end of the inner cavity of the machining table. First guide rods are fixedly installed on the left and right sides of the outer surface of the front end of the connecting arm. Second guide rings are fixedly installed in the middle of the outer surfaces of the left and right ends of the machining table. The second guide rings penetrate to one end of the inner cavity of the machining table. A second guide rod passes through the second guide ring. A third guide ring is installed on one side of the outer surface of the upper end of the support arm and penetrates to the other side of the outer surface of the support arm.

[0007] Preferably, the number of the arc-shaped tensioning limit block, connecting block, slide groove, triangular pressure block, support rod, compression spring, support arm, second guide ring and second guide rod are all two sets. The pressure sensor is fixed between the middle of the outer surface of the rear end of the connecting arm and the middle of the outer surface of the front end of the isosceles trapezoidal extrusion block. The two sets of triangular pressure blocks are located on the left and right sides of the isosceles trapezoidal extrusion block.

[0008] Preferably, the triangular pressure block is fixedly installed on the outer surface of one end of the movable block near the isosceles trapezoidal extrusion block, the middle part of the upper outer surface of the movable block is fixedly connected to the lower outer surface of the support rod, and the outer wall of the support rod is slidably connected to the slide groove.

[0009] Preferably, one end of the outer surface of the second guide rod is fixedly connected to the middle of the outer surface of the movable block away from the triangular pressure block, the compression spring is movably sleeved on the outer wall of the second guide rod near the movable block, the two sets of support arms are fixed on the left and right sides of the bottom of the processing table cavity, and the second guide rod passes through the third guide ring.

[0010] Preferably, the compression spring is fixed between the movable block and the support arm, and the outer wall of the second guide rod is slidably connected to the third guide ring and the second guide ring.

[0011] Preferably, after the piston rod of the hydraulic rod extends, it drives the isosceles trapezoidal extrusion block to move backward through the connecting arm. The two inclined sides of the isosceles trapezoidal extrusion block symmetrically extrude the inclined surfaces of the two sets of triangular pressure blocks, forcing the two sets of triangular pressure blocks to drive their respective connected movable blocks to move horizontally in opposite directions, thereby driving the arc-shaped tensioning limit blocks on both sides to move in opposite directions to achieve internal tensioning of the workpiece.

[0012] Preferably, the two sets of arc-shaped tensioning limit blocks are configured to radially tension the blade protection ring from the inner wall of the blade protection ring to be processed; the outer arc surface shape of the arc-shaped tensioning limit block is adapted to the inner wall contour of the blade protection ring, and anti-slip texture is provided on its outer arc surface.

[0013] (III) Beneficial Effects Compared with the prior art, this utility model provides a tensioning mechanism for machining thin-walled parts of aircraft, which has the following advantages: 1. The tensioning mechanism for machining thin-walled parts of aircraft uses a hydraulic rod drive mechanism to cause two sets of arc-shaped tensioning limit blocks to expand outward from the inside of the workpiece (such as a propeller protection ring) to achieve radial tensioning. This tensioning method ensures that the workpiece is subjected to uniform force, avoiding the problems of crushing, warping or deformation of thin-walled parts caused by concentrated clamping force in traditional external fixtures. It is particularly suitable for machining thin-walled parts with poor rigidity, effectively ensuring the machining accuracy of the workpiece and the quality of the finished product.

[0014] 2. This tensioning mechanism for machining thin-walled aircraft parts uses the isosceles trapezoidal extrusion block and the inclined surface of the triangular pressure block to efficiently and smoothly convert the linear thrust of the hydraulic rod into the symmetrical horizontal movement of the two movable blocks. The power transmission is stable. At the same time, the outer arc shape of the arc-shaped tensioning limit block is adapted to the inner wall contour of the workpiece and is provided with anti-slip texture, which increases the contact area and friction, ensuring that the workpiece will not loosen or rotate during the machining process, thus improving the safety and reliability of the machining operation.

[0015] 3. The tensioning mechanism for processing thin-walled parts of aircraft is equipped with a pressure sensor between the connecting arm and the isosceles trapezoidal extrusion block. The sensor can monitor and control the tension force in real time. Operators can preset appropriate tension forces according to the material and thickness of different workpieces, which can ensure sufficient fixing force and effectively avoid damage to the workpiece due to excessive tension force.

[0016] 4. The tensioning mechanism for processing thin-walled parts of an aircraft has an arc-shaped tensioning limit block that is detachably mounted on a support rod via a connecting block and bolts. This modular design allows for the quick replacement of arc-shaped tensioning limit blocks with different curvatures or sizes to meet the processing needs of various specifications of thin-walled parts. It has strong applicability and also facilitates the individual replacement of worn tensioning limit blocks, reducing maintenance costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a tensioning mechanism for machining thin-walled parts of an aircraft according to the present invention.

[0018] Figure 2 This is a partial top cross-sectional view of a tensioning mechanism for machining thin-walled parts of an aircraft according to the present invention.

[0019] Figure 3 This is a schematic diagram of the arc-shaped tensioning limit block in the tensioning mechanism for machining thin-walled parts of an aircraft according to the present invention.

[0020] Figure 4 This is a schematic diagram of the structure of the tensioning mechanism for machining thin-walled parts of an aircraft after fixing the propeller protective ring.

[0021] In the diagram: 1. Processing table; 2. Slide groove; 3. Arc-shaped tensioning limit block; 4. Connecting block; 5. Support rod; 6. Hydraulic rod; 7. First guide ring; 8. First guide rod; 9. Second guide ring; 10. Second guide rod; 11. Isosceles trapezoidal extrusion block; 12. Pressure sensor; 13. Connecting arm; 14. Movable block; 15. Triangular pressure block; 16. Support arm; 17. Third guide ring; 18. Compression spring; 19. Anti-slip texture. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0023] like Figure 1-4 As shown, the present invention provides a tensioning mechanism for machining thin-walled parts of aircraft, which mainly consists of a machining table 1, a drive assembly, a transmission assembly, and a tensioning assembly. The machining table 1 serves as the supporting foundation for the entire mechanism and has an installation chamber inside. A sliding groove 2 is provided on each of the left and right sides of the upper outer surface of the machining table 1, extending to the upper part of the installation chamber.

[0024] The tensioning assembly includes two sets of symmetrically arranged arc-shaped tensioning limit blocks 3. A connecting block 4 is fixedly installed in the center of the inner side of each arc-shaped tensioning limit block 3, and this connecting block 4 is detachably fixed to the upper outer surface of a support rod 5 by bolts. The lower part of the support rod 5 passes through the slide groove 2 and extends into the mounting cavity of the machining table 1. The outer arc shape of the arc-shaped tensioning limit block 3 is adapted to the inner wall contour of the thin-walled part of the aircraft to be processed (e.g., the protective ring of a UAV propeller), and its outer arc surface is machined with anti-slip textures 19 to increase friction and prevent the workpiece from sliding or rotating during processing.

[0025] The drive assembly includes a hydraulic rod 6 fixedly mounted on the middle of the outer surface of the front end of the machining table 1. The piston rod of the hydraulic rod 6 extends horizontally rearward into the interior of the machining table 1.

[0026] The transmission assembly is located in the mounting chamber of the processing table 1, and is used to convert the linear motion of the hydraulic rod 6 into the opposing horizontal motion of two sets of arc-shaped tensioning and limiting blocks 3. The core of the transmission assembly includes a connecting arm 13, an isosceles trapezoidal extrusion block 11, two sets of movable blocks 14, and two sets of triangular pressure blocks 15. The middle part of the outer surface of the front end of the connecting arm 13 is fixedly connected to the end of the piston rod of the hydraulic rod 6. The middle part of the outer surface of the rear end of the connecting arm 13 is fixedly connected to the middle part of the outer surface of the front end of the isosceles trapezoidal extrusion block 11 through a pressure sensor 12, which is used to monitor the tension force in real time. The left and right inclined sides of the isosceles trapezoidal extrusion block 11 are symmetrically arranged.

[0027] The upper outer surface of each movable block 14 is fixedly connected to the lower end of a support rod 5, allowing the movable block 14 to drive the support rod 5 to slide horizontally along the slide groove 2. A triangular pressure block 15 is fixedly installed on the outer surface of each movable block 14 near the isosceles trapezoidal extrusion block 11. The inclined surfaces of the two sets of triangular pressure blocks 15 are respectively opposite to the left and right inclined sides of the isosceles trapezoidal extrusion block 11.

[0028] To ensure smooth movement, a first guide ring 7 is fixedly installed on each of the left and right sides of the outer surface of the front end of the processing table 1, and the first guide ring 7 extends through to the front end of the inner cavity of the processing table 1. Two first guide rods 8 are fixedly installed on the left and right sides of the outer surface of the front end of the connecting arm 13, and each first guide rod 8 slides through a first guide ring 7 to guide the forward and backward movement of the connecting arm 13.

[0029] Similarly, a second guide ring 9 is fixedly installed in the middle of the outer surface at both ends of the processing table 1, and the second guide ring 9 extends through the inner cavity of the processing table 1. A second guide rod 10 is fixedly connected to the middle of the outer surface of the end of each movable block 14 away from the triangular pressure block 15. The second guide rod 10 slides through the corresponding second guide ring 9 and extends outward to guide and limit the horizontal movement of the movable block 14.

[0030] A support arm 16 is fixed on each of the left and right sides of the bottom of the mounting chamber. A third guide ring 17 is installed on one side of the upper outer surface of each support arm 16, extending through to the other side of the support arm 16. The inner part of the second guide rod 10 simultaneously slides through the third guide ring 17. A compression spring 18 is movably fitted on the section of the second guide rod 10 between the movable block 14 and the support arm 16. One end of the compression spring 18 abuts against the movable block 14, and the other end abuts against the support arm 16, providing a restoring force for the movable block 14.

[0031] The working principle of this utility model is as follows: In the initial state, the piston rod of the hydraulic rod 6 is in the retracted state, and the isosceles trapezoidal compression block 11 is positioned forward, without applying pressure to the triangular pressure block 15. At this time, the movable blocks 14 on both sides are in a state of inward contraction under the elastic force of their respective compression springs 18, which drives the support rod 5 and the arc-shaped tensioning limit block 3 to also be in the contracted position.

[0032] During operation, the thin-walled part to be processed (such as a propeller protective ring) is placed on the processing table 1 and fitted over the two sets of arc-shaped tensioning and limiting blocks 3 in a retracted state. The hydraulic rod 6 is activated, causing its piston rod to extend backward (i.e., into the processing table 1). The piston rod pushes the connecting arm 13 backward, and the connecting arm 13 drives the first guide rod 8 to slide along the first guide ring 7, ensuring a stable motion trajectory. Simultaneously, the connecting arm 13, through the pressure sensor 12, pushes the isosceles trapezoidal extrusion block 11 backward in sync.

[0033] When the isosceles trapezoidal pressing block 11 moves backward, its two inclined sides begin to symmetrically press the inclined surfaces of the triangular pressing blocks 15 on both sides. Through the cooperation of the inclined surfaces, the backward thrust is decomposed into a force that forces the two sets of triangular pressing blocks 15 and the movable block 14 fixed thereto to move in opposite directions in the horizontal direction (i.e., move away from the center line of the mechanism). The movable block 14 drives the second guide rod 10 to slide outward along the second guide ring 9 and the third guide ring 17, while compressing the compression spring 18. The movement of the movable block 14 is transmitted through the support rod 5, ultimately driving the two sets of arc-shaped tensioning limit blocks 3 to move in opposite directions horizontally under the constraint of the slide groove 2, expanding outward from the inside of the workpiece (blade protection ring) until the anti-slip texture 19 on its outer arc surface tightly and evenly abuts against the inner wall of the workpiece, achieving radial tensioning and fixing. The pressure sensor 12 can provide real-time feedback of the tensioning force for precise control.

[0034] After processing is completed, the piston rod of the control hydraulic rod 6 retracts. The connecting arm 13 and the isosceles trapezoidal extrusion block 11 then return to their original positions, releasing the pressure on the triangular pressure block 15. At this time, the compressed compression spring 18 releases its elastic force, pushing the movable block 14 to return to its original position inward. The movable block 14, through the support rod 5, drives the arc-shaped tensioning limit block 3 to retract inward simultaneously, thereby releasing the workpiece, which can then be removed.

[0035] The arc-shaped tensioning limit block 3 is connected to the support rod 5 through the connecting block 4 and bolts, which makes it easy to replace the appropriate arc-shaped tensioning limit block 3 according to the workpiece with different inner diameter or contour, thus enhancing the versatility of the mechanism.

[0036] Supplementary notes regarding the control of pressure sensor 12 and hydraulic rod 6: Pressure sensor 12 detects the thrust applied to the isosceles trapezoidal compression block 11 during the tensioning process in real time and converts the thrust signal into an electrical signal output. This electrical signal is transmitted to an external control system (not shown in the figure), which typically includes a signal amplifier, an analog-to-digital converter, a programmable logic controller (PLC) or microprocessor, and a hydraulic servo valve. The control system compares the received pressure signal with preset safety tensioning force thresholds corresponding to different workpiece materials and thicknesses. When the pressure value reaches the preset threshold, the control system sends a command to the hydraulic circuit of the hydraulic rod 6 to stop or maintain the pushing action of the hydraulic rod 6 by adjusting the hydraulic servo valve, thereby achieving precise closed-loop control of the tensioning force and preventing overload damage to thin-walled parts. It should be noted that this method of precise force control of hydraulic actuators based on sensor feedback is a mature and widely used existing technology in the fields of automated fixtures and CNC machining. Its specific circuit and program implementation is not the inventive point of this utility model, therefore, the applicant will not elaborate further on it.

[0037] It should be noted that, in this document, relational terms such as first and second (number one, number two), etc., are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0038] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A tensioning mechanism for machining thin-walled parts of aircraft, comprising a machining table (1), characterized in that: The upper outer surface of the processing table (1) is provided with sliding grooves (2) on both the left and right sides. The processing table (1) is provided with an installation chamber, and the sliding grooves (2) extend to the upper left and right sides of the installation chamber. A support rod (5) passes through the sliding grooves (2). The installation chamber is provided with a pressure sensor (12), a connecting arm (13), an isosceles trapezoidal extrusion block (11), a movable block (14), a triangular pressure block (15), a support arm (16), and a compression spring (18). The upper left and right sides of the processing table (1) are provided with arc-shaped tensioning limit blocks (3). A connecting block (4) is fixedly installed in the middle of the inner side of the arc-shaped tensioning limit block (3). The connecting block (4) is fixed to the upper outer surface of the support rod (5) by bolts. A hydraulic rod (6) is installed in the middle of the front outer surface of the processing table (1). One end of the piston rod in the hydraulic rod (6) extends into the interior of the processing table (1) and is fixedly connected to the middle of the front end of the connecting arm (13). A first guide ring (7) is fixedly installed on the left and right sides of the front end of the processing table (1). The first guide ring (7) penetrates to the front end of the inner cavity of the processing table (1). A first guide rod (8) is fixedly installed on the left and right sides of the front end of the connecting arm (13). A second guide ring (9) is fixedly installed in the middle of the outer surfaces of the left and right ends of the processing table (1). The second guide ring (9) penetrates to one end of the inner cavity of the processing table (1). A second guide rod (10) penetrates through the second guide ring (9). A third guide ring (17) is installed on one side of the upper outer surface of the support arm (16) and penetrates to the other side of the outer surface of the support arm (16).

2. The tensioning mechanism for machining thin-walled parts of aircraft according to claim 1, characterized in that: The number of the arc-shaped tensioning limit block (3), connecting block (4), slide groove (2), triangular pressure block (15), support rod (5), compression spring (18), support arm (16), second guide ring (9) and second guide rod (10) are all two sets. The pressure sensor (12) is fixed between the middle of the outer surface of the rear end of the connecting arm (13) and the middle of the outer surface of the front end of the isosceles trapezoidal extrusion block (11). The two sets of triangular pressure blocks (15) are located on the left and right sides of the isosceles trapezoidal extrusion block (11).

3. The tensioning mechanism for machining thin-walled parts of aircraft according to claim 2, characterized in that: The triangular pressure block (15) is fixedly installed on the outer surface of the movable block (14) near the isosceles trapezoidal extrusion block (11). The middle part of the upper outer surface of the movable block (14) is fixedly connected to the lower outer surface of the support rod (5). The outer wall of the support rod (5) is slidably connected to the slide groove (2).

4. The tensioning mechanism for machining thin-walled parts of aircraft according to claim 3, characterized in that: One end of the outer surface of the second guide rod (10) is fixedly connected to the middle of the outer surface of the movable block (14) away from the triangular pressure block (15). The compression spring (18) is movably sleeved on the outer wall of the second guide rod (10) near the movable block (14). The two sets of support arms (16) are fixed on the left and right sides of the bottom of the inner cavity of the processing table (1). The second guide rod (10) passes through the third guide ring (17).

5. The tensioning mechanism for machining thin-walled parts of aircraft according to claim 4, characterized in that: The compression spring (18) is fixed between the movable block (14) and the support arm (16), and the outer wall of the second guide rod (10) is slidably connected to the third guide ring (17) and the second guide ring (9).

6. The tensioning mechanism for machining thin-walled parts of aircraft according to claim 5, characterized in that: After the piston rod of the hydraulic rod (6) extends, it drives the isosceles trapezoidal extrusion block (11) to move backward through the connecting arm (13). The two inclined sides of the isosceles trapezoidal extrusion block (11) symmetrically extrude the inclined surfaces of the two sets of triangular pressure blocks (15), forcing the two sets of triangular pressure blocks (15) to drive their respective connected movable blocks (14) to move horizontally in opposite directions, thereby driving the arc-shaped tensioning limit blocks (3) on both sides to move in opposite directions to achieve internal tensioning of the workpiece.

7. The tensioning mechanism for machining thin-walled parts of aircraft according to claim 6, characterized in that: The two sets of arc-shaped tensioning limit blocks (3) are configured to radially tension the inner wall of the blade protection ring to be processed; the outer arc surface shape of the arc-shaped tensioning limit block (3) is adapted to the inner wall contour of the blade protection ring, and anti-slip texture (19) is provided on its outer arc surface.

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