Fixing device for thin-wall workpiece machining

Abstract

The invention relates to the technical field of machining equipment, in particular to a thin-wall workpiece machining fixing device which comprises a fixing base and a plurality of suction cups. The suckers are connected to the periphery of the fixing base through connecting rods so that the suckers can be distributed on the periphery of the fixing base and protrude out of the surface of the fixing base. An air draft channel is arranged in the fixed seat; and the plurality of connecting rods are tubular and are communicated with the air draft channel. The fixing base is fixed to a machining table of a machine tool, the fixing base is sleeved with the thin-wall workpiece, and the suction cup abuts against the inner wall of the workpiece. The air draft channel communicates with an air pump, and then air is exhausted to enable the sucker to suck the workpiece. The workpiece and the fixing base are connected into a whole, and shaking is avoided. The workpiece is supported through the connecting rod, and deformation during machining is avoided. The suction surface of the sucker is provided with a silica gel sucker mechanism.

Description

Technical Field

[0001] This invention relates to the technical field of machining equipment, and more specifically, to a fixing device for machining thin-walled workpieces. Background Technology

[0002] In today's rapidly developing machinery manufacturing industry, aerospace, automotive, and electronic communications sectors are facing increasingly stringent requirements for lightweight and high-precision components. Thin-walled parts, with their significant advantages such as light weight, high material utilization, and compact structure, are widely used in the key structures of various core equipment. Thin-walled parts typically refer to components with a small ratio of wall thickness to feature dimensions. Their structural characteristics make them highly susceptible to deformation under external forces during processing, which in turn affects the dimensional accuracy, form and position tolerances, and surface quality of the components. Therefore, the processing stability and precision control of thin-walled parts has become one of the core technical challenges in the field of machining.

[0003] As an indispensable key piece of equipment in the machining process, the core function of a fixture is to achieve precise positioning and reliable clamping of the workpiece, providing a stable reference for subsequent cutting operations. For the machining of thin-walled parts, the clamping performance of the fixture directly determines the quality of the machining. Currently, most mainstream fixtures for machining thin-walled parts on the market are designed based on traditional clamping principles, mainly using mechanical clamping mechanisms such as chucks, vises, and pressure plates to apply clamping force to fix the workpiece. However, due to the inherent poor rigidity and weak deformation resistance of thin-walled parts, traditional fixtures struggle to balance the contradiction between "reliable clamping" and "avoiding deformation" in practical applications, leading to frequent quality problems during machining and severely restricting the machining efficiency and industrial application of thin-walled parts.

[0004] Specifically, when using traditional clamps to hold thin-walled parts, increasing the clamping force to ensure stability can lead to elastic or even plastic deformation. This deformation not only causes significant discrepancies between the actual and designed dimensions of the machined workpiece, failing to meet accuracy requirements, but it can also generate residual stress within the workpiece. This stress release during subsequent use can further lead to dimensional drift, structural failure, and other potential problems. Especially in aerospace and other fields with extremely high reliability requirements, such defects can directly cause equipment malfunctions, resulting in serious safety accidents and economic losses. For example, in the machining of critical thin-walled parts such as aero-engine blades and automotive gearbox housings, deformation defects caused by excessive clamping force have led to a surge in component scrap rates, significantly increasing production costs.

[0005] Conversely, reducing the clamping force to avoid deformation can reduce the risk of workpiece deformation to some extent, but it leads to insufficient clamping stability. During machining, when the workpiece is subjected to external forces such as cutting forces and cutting vibrations, it is prone to displacement, loosening, or vibration. This unstable clamping state can cause a series of problems: on the one hand, workpiece displacement can disrupt the machining datum, leading to deviations in the position of machining features and affecting the assembly accuracy of parts; on the other hand, cutting vibrations can cause irregular relative motion between the tool and the workpiece, which not only reduces the surface roughness of the workpiece but may also accelerate tool wear, shorten tool life, and generate harsh vibration noise, deteriorating the machining environment. In addition, workpiece loosening may also trigger impact loads during the cutting process, which in severe cases can even lead to tool breakage, workpiece ejection, and other safety accidents, threatening the personal safety of operators.

[0006] To address the aforementioned issues, industry professionals have attempted to improve the clamping effectiveness of traditional clamps by optimizing the clamping point positions and adding auxiliary supports. For example, multi-point clamping can replace single-point clamping, or flexible support blocks can be added to easily deformable areas of thin-walled parts. However, these improvements only alleviate deformation problems to a certain extent and cannot fundamentally resolve the core contradiction between clamping force and deformation risk. Uneven force distribution in multi-point clamping can still lead to localized stress concentration and deformation; adding flexible support blocks may increase the complexity of the clamping structure, reduce clamping efficiency, and is difficult to adapt to thin-walled parts of different shapes and sizes, resulting in poor versatility.

[0007] In summary, existing fixtures for machining thin-walled parts generally suffer from drawbacks such as difficulty in precisely controlling clamping force, which can easily lead to workpiece deformation or unstable clamping, failing to meet the current demands for high-precision and high-efficiency machining of thin-walled parts. Therefore, it is necessary to develop a new type of fixture that can precisely balance clamping stability and deformation resistance requirements, achieving a synergistic effect between reliable clamping and deformation control. Summary of the Invention

[0008] The purpose of this invention is to provide a fixing device for machining thin-walled workpieces, which can stably fix the workpieces and avoid significant deformation.

[0009] The embodiments of the present invention are achieved through the following technical solutions: A fixing device for machining thin-walled workpieces includes a fixing base and a plurality of suction cups; the plurality of suction cups are connected to the fixing base around the perimeter by connecting rods, so that the plurality of suction cups are distributed around the fixing base and protrude from the surface of the fixing base; the fixing base is provided with an exhaust duct; the plurality of connecting rods are tubular and communicate with the exhaust duct.

[0010] The mounting base is fixed to the machining table of the machine tool. A thin-walled workpiece is fitted over the mounting base, with the suction cup abutting against the inner wall of the workpiece. An air pump is connected to the exhaust duct, drawing air to allow the suction cup to adhere to the workpiece. This ensures the workpiece and mounting base are connected as a single unit, preventing movement. The workpiece is also supported by a connecting rod to prevent deformation during machining. The suction surface of the suction cup is equipped with a silicone suction cup mechanism.

[0011] Furthermore, the fixed base is hollow inside; the connecting rod; the fixed base is also provided with an airbag so that when the airbag is inflated, it pushes several of the connecting rods out; the fixed base is also provided with a fixing member in conjunction with the connecting rod so that the fixing member can fix the connecting rod to the fixed base; the airbag is connected to the air pump.

[0012] The mounting base has holes around its perimeter, and the connecting rod fits into these holes and can slide. When the airbag inflates, it pushes the suction cups firmly against the inner wall of the workpiece, allowing the positions of the suction cups to be quickly adjusted to the appropriate location and to adhere to the workpiece without complex adjustments. After adjustment, the connecting rod is locked in place using the fixing components. Then, deflating the airbag and mounting base will allow the suction cups to adhere to the inner wall of the workpiece.

[0013] Furthermore, the connecting rod is an iron pipe; each connecting rod is equipped with a magnet so that when the airbag contracts, it can drive the suction cup to retract.

[0014] When the workpiece needs to be removed, the airbag inflates until it abuts the connecting rod and adheres to it. The fixing component is released from the connecting rod, and the airbag is then deflated, causing the suction cup to retract. This completely separates the suction cup from the inner wall of the workpiece, facilitating workpiece placement and removal. After placing the workpiece, the airbag is inflated again, causing the suction cup to adhere tightly to the inner wall of the workpiece. Simply install a limiting device on the machining table and place the workpiece between the limiting devices; the suction of several suction cups will connect the workpiece and the fixing base into a single unit, achieving the purpose of machining positioning. Under the limiting device's control, workpiece clamping can be completed quickly, and the fixing process is simple and convenient. Alternatively, a clamp can be installed on the outside of the workpiece to achieve joint clamping. Because the workpiece has internal support, the clamp can also apply a greater clamping force.

[0015] Furthermore, the airbag includes a transverse airbag and a longitudinal airbag; the expansion direction of the transverse airbag points towards the periphery of the fixed base; the expansion direction of the longitudinal airbag is vertically upward.

[0016] In practice, the suction cups on the sides of the mounting base can be controlled to hold the workpiece in place first, and then the suction cups on the top of the mounting base can be extended. When the suction cups extend from all four sides, the surrounding limiting devices prevent workpiece displacement. Similarly, when the top suction cups extend, the workpiece is also held in place by the surrounding suction cups, preventing displacement. This allows for the installation of transverse and longitudinal airbags within the mounting component to control the extension of the surrounding and top suction cups, respectively.

[0017] Furthermore, the fixing base is provided with a plurality of connecting holes for the extension and retraction of the connecting rod; each connecting hole is provided with a set of fixing members; the fixing members include a rotating handle and a plurality of locking flaps; the plurality of locking flaps are disposed at the opening of the connecting hole and are evenly distributed around the opening; the rotating handle is annular and rotatably fitted onto the outside of the plurality of locking flaps; each locking flap is wedge-shaped in accordance with the inner wall of the rotating handle, so that when the rotating handle rotates, it can drive the plurality of locking flaps to move closer or further apart, thereby clamping or releasing the connecting rod.

[0018] The inner wall of the handle is set as an inclined surface to match each locking disc. The locking discs can be made of spring steel and open or clamp the connecting rod when the handle is rotated.

[0019] Furthermore, the fixed base is also provided with a locking mechanism; the locking mechanism includes a double-acting cylinder, a pull rope, and a fixed pulley; connecting ears are extended on both opposite sides of the rotating handle; the two ends of the pull rope are respectively connected to the two ends of the double-acting cylinder; the pull rope is tensioned through the fixed pulley and connected to the two connecting ears of the rotating handle, so that the rotating handle is driven to rotate when the double-acting cylinder is activated.

[0020] The cylinder rod of the double-acting cylinder passes through both ends of the cylinder body and extends outwards. During operation, one end of the cylinder rod extends while the other end retracts. The cylinder rod also works with multiple fixed pulleys connected to both ends of a pull rope, allowing the cylinder rod to move in either direction, causing the pull rope to slide in the opposite direction, which in turn rotates the handle in the opposite direction, thus retracting and releasing the connecting rod. The double-acting cylinder and pull rope enable pneumatic control of the locking and unlocking of the connecting rod, eliminating the need for manual control of the fixed components enclosed within the workpiece, achieving both controllability and convenience.

[0021] Furthermore, the fixing base is in the shape of a cuboid; at each of the four corners of the top surface of the fixing base, a rotating roller is provided to cooperate with the pull rope, so that the pull rope extends through the rotating roller to two adjacent surfaces of the fixing base; the pull rope is connected to the multiple connecting lugs it passes through.

[0022] The rotating roller allows the pull rope to pass more smoothly through the edges of the fixed base, reducing wear. A single pull rope connecting multiple handles via connecting lugs allows one locking mechanism to drive multiple sets of fixed components.

[0023] Furthermore, the connecting rod includes a telescopic section and a tightening section; the telescopic section and the tightening section are staggered to make the connecting rod Z-shaped; the telescopic section is slidably inserted through the connecting hole.

[0024] Once the mounting base is machined, the position of its connecting hole is fixed. However, the shapes of workpieces vary. To accommodate different workpieces, the connecting rod can be made curved, allowing the suction cup to correspond to the workpiece's connection point.

[0025] Furthermore, a sealing gasket is provided on the inner wall of the locking flap, so that the locking flap presses the sealing gasket tightly against the connecting rod. This prevents excessive leakage when air is drawn from inside the fixing seat, which would affect the adsorption effect on the workpiece.

[0026] Furthermore, both the lateral and longitudinal airbags are equipped with one-way valves to allow air to flow into the interior of the lateral and longitudinal airbags through the one-way valves.

[0027] During inflation, the one-way valve closes, ensuring that several connecting rods are ejected during the expansion of the transverse and longitudinal air chambers. During deflation, the one-way valve opens, allowing air within the mounting base to be drawn out through the air passages of the transverse and longitudinal air chambers, eliminating the need for a separate air extraction port for the mounting base. The one-way valve can also be set with a pressure threshold, allowing the transverse and longitudinal air chambers to retract under pressure during deflation, which in turn retracts several connecting rods. The one-way valve only opens when the connecting rods are retracted.

[0028] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects: 1. The system employs a combination structure consisting of a fixed base, several suction cups, tubular connecting rods, and an internal branched exhaust duct. The connecting rods evenly distribute the suction cups around the fixed base, protruding from its surface. The tubular connecting rods and the exhaust ducts are sealed and connected to form a complete airflow channel. This achieves uniform adsorption of the inner wall of thin-walled workpieces, firmly integrating the workpiece with the fixed base and avoiding the shaking caused by uneven contact force in traditional fixtures. Furthermore, the connecting rods provide multi-point support to the inner wall of the workpiece to resist radial cutting pressure, suppressing deformation from within. Combined with the elasticity and sealing properties of the silicone suction cups, this enhances adsorption reliability while preventing indentation damage to the inner wall of the workpiece, ensuring surface quality.

[0029] 2. The fixed base adopts an internal hollow design, with the connecting rod slidingly engaging with the hole in the fixed base. An airbag connected to the air pump is installed inside, and a fixing component is configured corresponding to the connecting rod. By inflating the airbag and pushing the connecting rod, the suction cup can be extended, which can quickly adapt to the inner wall of thin-walled workpieces of different sizes for close fitting and positioning without the need for manual adjustment, thus improving clamping efficiency. After the connecting rod is locked by the fixing component, air is drawn in for suction, which not only solves the problem of poor adaptability of traditional fixtures, but also simplifies the clamping process and reduces the difficulty of operation. The integrated air circuit design also simplifies the overall structure.

[0030] 3. The connecting rod is made of iron pipe, and magnets are installed at corresponding positions on the airbag. The connecting rod is attracted by the airbag when it is inflated. After the fixing parts are released, the airbag is deflated and the connecting rod is retracted, so that the suction cup is completely separated from the inner wall of the workpiece. This achieves automatic retraction of the suction cup and avoids scratching or deformation damage to the workpiece caused by manual disassembly. With the limit device of the processing table, the workpiece can be quickly positioned by the suction cup after placement, which is convenient and easy to fix. Moreover, the internal multi-point support allows the external auxiliary fixture to apply greater clamping force to ensure stability, which solves the problem of deformation caused by excessive external clamping force in traditional methods.

[0031] 4. The airbag adopts a horizontal + vertical split structure. The horizontal airbag is arranged horizontally to drive the connecting rods around it to extend, and the vertical airbag is arranged vertically to drive the connecting rod on the top surface to extend. It is inflated in stages by the air circuit control unit. First, the horizontal suction cup is pressed against the workpiece peripheral wall and the limiting device is used to achieve horizontal positioning. Then, the vertical suction cup extends to fit against the top surface, avoiding workpiece displacement caused by simultaneous extension in multiple directions. This achieves precise control of the suction cup extension sequence and improves positioning accuracy and clamping stability.

[0032] 5. The fastener adopts a beveled fit structure of a rotating handle and a spring steel locking disc. The locking disc is distributed circumferentially along the connecting hole. The inner wall of the rotating handle and the outer side of the locking disc are provided with wedge-shaped surfaces. Rotating the rotating handle can drive the locking disc to move closer or further away synchronously, realizing reliable clamping and loosening of the connecting rod. The spring steel material allows the locking disc to elastically return to its original position, and the wedge-shaped surface structure achieves self-locking, avoiding accidental rotation of the rotating handle during processing that could lead to locking failure, and ensuring the stability of the connecting rod support position.

[0033] 6. A locking mechanism consisting of a double-acting cylinder, a pull rope, and a fixed pulley is installed. The two ends of the pull rope are connected to the piston rod of the cylinder, and after being turned by the fixed pulley, they are connected to the connecting lug of the handle. The cylinder pulls the handle to rotate through bidirectional action, thereby realizing the automatic clamping and loosening of the fixed parts, replacing manual operation. This solves the operational problem caused by the sealing of the fixed seat after the workpiece is sleeved, and improves the convenience and automation of operation.

[0034] 7. Rotary assembly rollers are mounted at the corners of the top surface of the fixed base. The pull rope is turned through the rollers to connect to the side handle, converting sliding friction into rolling friction, reducing tension loss and making the transmission smoother. At the same time, it avoids wear on the pull rope and extends its service life. A single pull rope can be connected in series with multiple handle connecting ears to realize the synchronous driving of multiple sets of fixed parts by one set of mechanisms, simplifying the structural design and control logic.

[0035] 8. The connecting rod adopts a Z-shaped structure with the telescopic section and the clamping section staggered. The telescopic section slides with the connecting hole of the fixed seat, and the clamping section connects to the suction cup and the staggered angle can be preset. Through the staggered extension of the clamping section, the suction cup can accurately fit the effective support point of thin-walled workpieces with complex inner wall shapes or irregular curved surfaces, improve the adsorption and support effect, and expand the application range of the device.

[0036] 9. The inner wall of the locking flap is fitted with a rubber sealing gasket. When the connecting rod is clamped, the sealing gasket is squeezed to form a ring-shaped sealing structure, blocking the gap between the connecting rod and the connecting hole. This prevents external air leakage during air extraction, which could lead to insufficient negative pressure, ensuring the suction cup's adsorption stability and improving the device's sealing reliability.

[0037] 10. Both the horizontal and vertical airbags are equipped with one-way valves. The one-way valves open during inflation and automatically close after inflation to ensure stable air pressure. During deflating, the one-way valves open after the negative pressure reaches the threshold, connecting the airbag to the inside of the fixed seat. As the airbag contracts, it drives the connecting rod to retract, and the fixed seat is deflated through the airbag air passage. There is no need to set up a separate deflating port, which simplifies the air circuit design and realizes coordinated control of airbag contraction and deflating operations, thereby improving operational stability. Attached Figure Description

[0038] Figure 1 This is a schematic diagram showing the cooperation between the fixing device for thin-walled workpiece processing and the workpiece according to the present invention.

[0039] Figure 2 This is a schematic diagram of the fixing device for machining thin-walled workpieces according to the present invention.

[0040] Figure 3 for Figure 2 Enlarged view of point a in the middle.

[0041] Figure 4 A top-view sectional view of the fixture used for machining thin-walled workpieces when it is in conjunction with the workpiece.

[0042] Figure 5 A schematic diagram of the airbag in the fixing device for machining thin-walled workpieces after it has collapsed.

[0043] Figure 6 A schematic diagram of fixing the connecting rod.

[0044] Figure 7 This is a sectional view of the fixing device for machining thin-walled workpieces from the front view.

[0045] Figure 8 This is a schematic diagram showing the bending of a portion of the connecting rod.

[0046] Reference numerals: 1-Fixed base, 2-Suction cup, 3-Exhaust duct, 4-Connecting rod, 5-Processing table, 6-Workpiece, 7-Airbag, 8-Transverse airbag, 9-Vertical airbag, 10-Rotating handle, 11-Locking flap, 12-Double-acting cylinder, 13-Pull rope, 14-Fixed pulley, 15-Connecting ear, 16-Rotating roller, 17-Telescopic section, 18-Tightening section, 19-Limiting device, 20-Auxiliary clamp. Detailed Implementation

[0047] like Figures 1-8As shown, the fixing device for machining thin-walled workpiece 6 disclosed in this embodiment aims to solve the core contradiction in the prior art where traditional clamps struggle to balance reliable clamping and avoid deformation when holding thin-walled workpieces. Its core structure includes a fixing base 1 and several suction cups 2, achieving stable clamping of the thin-walled workpiece 6 through a combination of adsorption and support. The suction cups 2 are connected one-to-one to the perimeter of the fixing base 1 via connecting rods 4. After assembly, each suction cup 2 protrudes from the outer surface of the fixing base 1 and is evenly distributed along the circumference of the fixing base 1, ensuring a balanced distribution of clamping force on the workpiece 6. A through-flow exhaust duct 3 is provided inside the fixing base 1. This exhaust duct 3 extends in a branch-like structure to each connection point of the fixing base 1. The connecting rods 4 connecting the suction cups 2 and the fixing base 1 are all designed with a tubular structure, and their internal channels maintain a sealed connection with the exhaust duct 3 of the fixing base 1, forming a complete airflow channel.

[0048] In actual installation and use, the mounting base 1 is first fixed to the machining table 5 of the machine tool. The machining table 5 is the core load-bearing component of the machine tool. Its top surface has a flat mounting reference surface and is equipped with standard connection holes. The mounting base 1 can be detached by fasteners such as bolts. The load-bearing strength of the machining table 5 can meet the superimposed load of cutting force and workpiece 6 during the machining process, ensuring the stability of the mounting base 1 after installation.

[0049] When clamping workpiece 6, the thin-walled workpiece 6 is placed outside the fixed base 1, ensuring that each suction cup 2 accurately abuts against the inner wall of workpiece 6. Then, the exhaust duct 3 of the fixed base 1 is sealed to an external air pump, and the air pump is started to perform an air extraction operation. This creates a negative pressure environment between the tubular connecting rod 4 and the inside of the suction cup 2, thereby achieving adsorption and fixation of the inner wall of workpiece 6 through the suction cup 2. This firmly connects workpiece 6 and the fixed base 1 into a single unit, effectively avoiding the workpiece 6 shaking problem caused by uneven contact force during traditional clamping. Simultaneously, each connecting rod 4 provides multi-point support to the inner wall of workpiece 6 during the connection of the suction cup 2, resisting the radial pressure generated by the cutting force during processing and suppressing the deformation tendency of workpiece 6 from the inside. Combined with the silicone suction cup 2 mechanism, the silicone material possesses good elasticity and sealing properties, increasing the adhesion between the suction cup 2 and the inner wall of workpiece 6, improving adsorption reliability, and avoiding indentation damage to the inner wall of workpiece 6 caused by rigid contact, further ensuring the surface quality of workpiece 6.

[0050] To improve the adaptability of the device to thin-walled workpieces 6 of different sizes, the fixed base 1 adopts an internal hollow structure design, making the internal space of the fixed base 1 an exhaust duct 3. The connection between the connecting rod 4 and the fixed base 1 is set as a sliding fit structure. Specifically, the fixed base 1 has matching connection holes around its perimeter corresponding to each connecting rod 4, and the connecting rod 4 can slide freely along the axial direction of the connection holes. The hollow interior of the fixed base 1 is also equipped with an airbag 7, the arrangement of which corresponds to the inner end of each connecting rod 4. When the airbag 7 is inflated, it can simultaneously push several connecting rods 4 outward from the fixed base 1. At the same time, the fixed base 1 is equipped with a fixing component corresponding to the connection hole of each connecting rod 4. This fixing component can lock the connecting rod 4 to the fixed base 1 after it is adjusted to a suitable position, preventing displacement during processing. In addition, the airbag 7 is connected to the air pump adsorbed by the drive suction cup 2, realizing integrated control of the air circuit and simplifying the overall structural design.

[0051] The working principle of this structure is as follows: when clamping thin-walled workpieces 6 with different inner wall dimensions, the air bladder 7 is first inflated by an air pump. The pushing force generated by the expansion of the air bladder 7 acts on the inner end of each connecting rod 4, pushing the connecting rod 4 to extend the suction cups 2 outward until all suction cups 2 are tightly against the inner wall of the workpiece 6. This process eliminates the need for manual adjustment of the suction cup 2 position, quickly achieving the adhesion and positioning of the suction cups 2 with the inner wall of the workpiece 6, significantly improving clamping efficiency. After the suction cups 2 are in place, the connecting rods 4 are locked in place by a fixing component to ensure the stability of the supporting position of the connecting rods 4. Then, the air pump can be controlled to evacuate the air bladder 7 and the fixing seat 1, creating a negative pressure inside the suction cups 2 to achieve adsorption and fixation. This design, through the adaptive adjustment driven by the air bladder 7, solves the problem that traditional fixtures are difficult to adapt to thin-walled workpieces 6 of different sizes, while simplifying the clamping and adjustment process and reducing the difficulty of operation.

[0052] To further enhance the ease of handling workpiece 6, the connecting rod 4 is made of iron pipe, and magnets are fixedly installed on the airbag 7 corresponding to the position of each connecting rod 4. One end of the iron pipe is connected to the suction cup 2, and the other end is connected to the inside of the fixing base 1. The core function of this structural design is to realize the automatic retraction function of the suction cup 2. When it is necessary to remove workpiece 6, the airbag 7 is first inflated by the air pump, so that the airbag 7 expands and tightly abuts against the inner end of the connecting rod 4. At this time, the magnet on the airbag 7 and the iron pipe connecting rod 4 generate an adsorption force, realizing the temporary fixation of the two. Then, the fixing parts are released from the locking of the connecting rod 4, and the air pump is controlled to de-inflate the airbag 7. The airbag 7 contracts under negative pressure, and the adsorption force between the magnet and the connecting rod 4 drives the connecting rod 4 to retract into the fixing base 1, thereby completely separating the suction cup 2 from the inner wall of the workpiece 6. This avoids the scratching or deformation damage to the workpiece 6 that may be caused by manual disassembly, and also avoids the suction cup 2 contacting the workpiece 6 and obstructing the handling of workpiece 6. When clamping workpiece 6, simply inflate the airbag 7 again to push the connecting rod 4 to extend the suction cup 2 and press it against the inner wall of workpiece 6. With the help of the limiting device 19 preset on the processing table 5, after placing workpiece 6 between the limiting devices 19, the suction effect of several suction cups 2 can make workpiece 6 and fixed seat 1 form a stable whole, achieving rapid positioning. The fixing process is simple and convenient. At the same time, auxiliary clamps 20 can be set on the outside of workpiece 6 to achieve joint clamping. Since there are already multiple points of support inside workpiece 6, the external clamps can apply greater clamping force to ensure processing stability, effectively solving the problem of workpiece 6 deformation caused by excessive external clamping force of traditional clamps.

[0053] To achieve precise control over the extension sequence of the suction cups 2 and further improve positioning accuracy, the airbag 7 adopts a split structure design, specifically including a transverse airbag 8 and a longitudinal airbag 9. The transverse airbag 8 is fixedly assembled in the horizontal direction inside the fixed base 1, and its expansion direction points to the perimeter of the fixed base 1, used to drive the connecting rods 4 around the fixed base 1 to extend. The longitudinal airbag 9 is assembled in the upper part inside the fixed base 1, and its expansion direction is vertically upward, used to drive the connecting rods 4 on the top surface of the fixed base 1 to extend. The working principle of this structure is that, in the actual clamping process, the air circuit control unit first inflates the transverse airbag 8, causing several suction cups 2 on the side of the fixed base 1 to extend synchronously and press against the inner peripheral wall of the workpiece 6. At this time, the limiting device 19 around the processing table 5 forms a transverse limit on the workpiece 6, preventing the workpiece 6 from shifting in the transverse direction. After the transverse suction cups 2 are pressed and positioned, the longitudinal airbag 9 is then inflated, driving the suction cups 2 on the top surface of the fixed base 1 to extend vertically upward and press against the top surface of the inner wall of the workpiece 6. Since the suction cups 2 around the perimeter have already completed the lateral positioning and adsorption of the workpiece 6, the extension of the longitudinal suction cup 2 will not cause the workpiece 6 to shift upwards, thus ensuring positioning accuracy. Through the time-division control of the lateral airbags 8 and the longitudinal airbags 9, the orderly coordination of the extension actions of the suction cups 2 in different directions is achieved, avoiding the workpiece 6 offset problem that may be caused by simultaneous extension in multiple directions, and further improving the stability and accuracy of clamping.

[0054] To ensure reliable locking of the connecting rod 4, the fixing base 1 has a matching connecting hole corresponding to the sliding hole of each connecting rod 4, and each connecting hole is equipped with a set of fixing components, which include a handle 10 and several locking flaps 11. Figure 6 As shown, several locking petals 11 are evenly distributed circumferentially along the opening of the connecting hole. The locking petals 11 are made of spring steel and possess good elastic restoring capability. The rotating handle 10 has a ring-shaped structure and is rotatably fitted onto the outside of the locking petals 11. The inner wall of the rotating handle 10 adopts a wedge-shaped structure design, and the outer wall of each locking petal 11 is matched with a corresponding wedge-shaped surface on the inner wall of the rotating handle 10, forming a beveled fit structure. When the rotating handle 10 is rotated clockwise, the wedge-shaped surface on the inner wall of the rotating handle 10 slides relative to the wedge-shaped surface on the outer side of the locking petals 11, and the wedge-shaped surface guides the locking petals 11 to simultaneously move towards the center of the connecting hole. When the rotating handle 10 is rotated counterclockwise, the locking petals 11 simultaneously move away from the center of the connecting hole. When the locking petals 11 move closer, their inner ends are tightly fitted against the outer wall of the connecting rod 4, achieving clamping and fixing of the connecting rod 4. When the locking petals 11 move away, the clamping state is released, and the connecting rod 4 can slide freely. When the spring steel locking disc 11 is released by rotating the handle 10, it can automatically reset under its own elasticity, ensuring the reliability of the next clamping action.

[0055] To achieve automated control of the fasteners and solve the problem of manual operation of fasteners enclosed inside the workpiece 6, the fixing base 1 is also equipped with a locking mechanism, which includes a double-acting cylinder 12, a pull rope 13, and a fixed pulley 14. Connecting ears 15 extend outwards from both opposite sides of the handle 10. The two ends of the pull rope 13 are fixedly connected to the ends of the two piston rods of the double-acting cylinder 12. The piston rods of the double-acting cylinder 12 pass through both ends of the cylinder body and extend outwards, allowing for synchronous movement of one end extending and the other end retracting during operation, similar to the cylinders in the Airtac SC series. The fixed pulley 14 is fixedly mounted to the corresponding position of the fixing base 1 via a bracket. The pull rope 13 passes around the fixed pulley 14 to achieve direction conversion and maintain tension, ultimately connecting to the two connecting ears 15 of the handle 10. When one piston rod of the double-acting cylinder 12 extends and the other retracts, the pull rope 13 pulls the handle 10 to rotate in one direction, causing the locking disc 11 to close and clamp the connecting rod 4. When the double-acting cylinder 12 moves in the opposite direction, the pull rope 13 pulls the handle 10 to rotate in the opposite direction, and the locking disc 11 resets under its own elasticity, releasing the connecting rod 4. This design replaces manual operation with pneumatic control, realizing remote controllability of the fixing component. It is especially suitable for scenarios where the fixing seat 1 is closed after the workpiece 6 is set, greatly improving the convenience of operation and the degree of automation.

[0056] To adapt to the structural layout of the rectangular fixed base 1 and improve the stability of the pull rope 13 transmission, rotating rollers 16 are rotatably mounted at the four corners of the top surface of the fixed base 1. The axis of the rotating rollers 16 is consistent with the extension direction of the corners. After the pull rope 13 extends from the inside of the fixed base 1 to the top surface, it turns around the circumference of the rotating rollers 16 and extends to the adjacent side of the fixed base 1, where it is fixedly connected to the connecting lugs 15 of the corresponding handles 10 of the connecting rods 4 on the side. The rotating rollers 16 can convert the sliding friction between the pull rope 13 and the corners of the fixed base 1 into rolling friction, which reduces the friction during the pulling process of the pull rope 13, making the transmission smoother, and effectively avoids wear caused by long-term friction between the pull rope 13 and the corners, thus extending the service life of the pull rope 13. At the same time, one pull rope 13 can be connected to the connecting lugs 15 of multiple handles 10 in sequence, so that one locking mechanism can synchronously drive the action of multiple sets of fixing parts, realizing the synchronous locking and unlocking of the multi-directional connecting rods 4, further simplifying the structural design and control logic.

[0057] To improve the adaptability of the device to thin-walled workpieces 6 of different shapes, the connecting rod 4 adopts a segmented structure design, specifically including a telescopic section 17 and a clamping section 18. The telescopic section 17 and the clamping section 18 are fixedly connected by welding or threaded connection, and their axes are offset, making the entire connecting rod 4 form a Z-shaped structure. The telescopic section 17 is a smooth shaft structure that can slide through the connecting hole of the fixed base 1, forming a sliding fit with the fixed base 1; the end of the clamping section 18 is fixedly connected to the suction cup 2, and its offset angle can be preset according to the inner wall shape of common thin-walled workpieces 6. Since the connecting hole of the fixed base 1 is fixed, the traditional straight rod structure of the connecting rod 4 is difficult to adapt to thin-walled workpieces 6 with complex inner wall shapes or irregular curved surfaces. However, the Z-shaped connecting rod 4 can extend through the offset of the clamping section 18, allowing the suction cup 2 to accurately correspond to the effective support point of the inner wall of the workpiece 6, improving the fit between the suction cup 2 and the inner wall of the workpiece 6, thereby enhancing the adsorption and support effect and expanding the applicability of the device.

[0058] To ensure airtightness during the evacuation process and prevent air leakage from affecting the adsorption effect, sealing gaskets are fixedly attached to the inner wall of the locking flap 11. The sealing gaskets are made of wear-resistant and elastic rubber. When the locking flap 11 moves towards the center to clamp the connecting rod 4 under the drive of the rotating handle 10, the sealing gaskets on the inner wall of the locking flap 11 are simultaneously squeezed and tightly attached to the outer wall of the connecting rod 4, forming an annular sealing structure. This effectively blocks the gap between the connecting rod 4 and the connecting hole, preventing external air from leaking through the gap and causing insufficient negative pressure when evacuating the inside of the fixed seat 1. This ensures that the suction cup 2 can stably adsorb the workpiece 6, improving the sealing reliability of the device.

[0059] To simplify the air circuit design and achieve coordinated control of airbag 7 contraction and deflating operations, one-way valves are installed on both the transverse airbag 8 and the longitudinal airbag 9. The one-way valve is configured to allow air to flow into the airbag 7 only from the outside. During inflation, compressed air from the air pump opens the one-way valve, inflating the airbag 7. After inflation, the one-way valve automatically closes due to its elasticity, ensuring stable air pressure inside the airbag 7 and allowing the connecting rod 4 to remain extended under the support of the airbag 7. During deflating, the one-way valve has a specific air pressure threshold. When the negative pressure inside the mounting base 1 reaches this threshold, the one-way valve opens, connecting the interior of the mounting base 1 with the interior of the airbag 7. At this time, the airbag 7 contracts under the negative pressure, causing the connecting rod 4 to retract into the mounting base 1. Simultaneously, external air will not flow back into the mounting base 1 through the one-way valve. This design eliminates the need for a separate air extraction port for the fixed base 1. Air extraction can be achieved through the air passage of the airbag 7, simplifying the air path structure. At the same time, the pressure threshold control of the one-way valve ensures the orderly coordination between the retraction action of the connecting rod 4 and the air extraction operation, thereby improving the operational stability of the device.

Claims

1. A fixing device for machining thin-walled workpieces, characterized in that: It includes a fixed base and several suction cups; the suction cups are connected to the fixed base around the perimeter by connecting rods, so that the suction cups are distributed around the fixed base and protrude from the surface of the fixed base; the fixed base is provided with an exhaust duct; the connecting rods are tubular and communicate with the exhaust duct.

2. The fixing device for machining thin-walled workpieces according to claim 1, characterized in that: The fixed base is hollow inside; the connecting rod; the fixed base is also provided with an airbag so that when the airbag is inflated, it pushes several of the connecting rods out; the fixed base is also provided with a fixing member in conjunction with the connecting rod so that the fixing member can fix the connecting rod to the fixed base; the airbag is connected to an air pump.

3. The fixing device for machining thin-walled workpieces according to claim 2, characterized in that: The connecting rod is an iron pipe; each airbag is equipped with a magnet in conjunction with the connecting rod, so that when the airbag contracts, it can drive the suction cup to retract.

4. The fixing device for machining thin-walled workpieces according to claim 3, characterized in that: The airbag includes a transverse airbag and a longitudinal airbag; the expansion direction of the transverse airbag points to the perimeter of the fixed base; the expansion direction of the longitudinal airbag is vertically upward.

5. The fixing device for machining thin-walled workpieces according to claim 4, characterized in that: The fixing base is provided with a plurality of connecting holes for the extension and retraction of the connecting rod; each connecting hole is provided with a set of fixing members; the fixing members include a rotating handle and a plurality of locking flaps; the plurality of locking flaps are disposed at the opening of the connecting hole and are evenly distributed around the opening; the rotating handle is annular and rotatably fitted onto the outside of the plurality of locking flaps; each locking flap is wedge-shaped in accordance with the inner wall of the rotating handle, so that when the rotating handle rotates, it can drive the plurality of locking flaps to move closer or further apart, thereby clamping or releasing the connecting rod.

6. The fixing device for machining thin-walled workpieces according to claim 5, characterized in that: The fixed base is also provided with a locking mechanism; the locking mechanism includes a double-acting cylinder, a pull rope and a fixed pulley; connecting ears are provided on both opposite sides of the handle; the two ends of the pull rope are respectively connected to the two ends of the double-acting cylinder; the pull rope is tensioned through the fixed pulley and connected to the two connecting ears of the handle, so that the handle is driven to rotate when the double-acting cylinder is activated.

7. The fixing device for machining thin-walled workpieces according to claim 6, characterized in that: The fixing base is rectangular; at each of the four corners of the top surface of the fixing base, a rotating roller is provided to cooperate with the pull rope, so that the pull rope extends through the rotating roller to two adjacent surfaces of the fixing base; the pull rope is connected to the multiple connecting lugs it passes through.

8. The fixing device for machining thin-walled workpieces according to claim 7, characterized in that: The connecting rod includes a telescopic section and a tightening section; the telescopic section and the tightening section are staggered to make the connecting rod Z-shaped; the telescopic section is slidably inserted through the connecting hole.

9. The fixing device for machining thin-walled workpieces according to claim 8, characterized in that: The inner wall of the locking flap is provided with a sealing gasket so that the locking flap presses the sealing gasket against the connecting rod.

10. The fixing device for machining thin-walled workpieces according to claim 9, characterized in that: Both the transverse and longitudinal airbags are equipped with one-way valves to allow air to flow into the transverse and longitudinal airbags through the one-way valves.

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