Link-type inner support fixing tool for cylindrical workpiece

Abstract

The utility model relates to the field of cylindrical workpiece clamping technology discloses a connecting rod type inner support fixing tool for cylindrical workpiece, including base, support column, fixed component, top annular slide and inner support component, support column is arranged on the base, is equipped with fixed component, top annular slide and drive mechanism on the support column, fixed component is provided with two groups, two groups of fixed component are spaced apart and close to the base arrangement, top annular slide is slidably sleeved on the support column and close to the free end of support column arrangement, the power output end of drive mechanism connects top annular slide and drives top annular slide to move along the axial movement of support column, inner support component is rotatably connected on two groups of fixed component through first connecting rod and is combined to constitute four connecting rod mechanism, and inner support component is rotatably connected on top annular slide through second connecting rod, inner support component is provided with multiple groups, and multiple groups of inner support component are spaced apart along the equidistant interval of support column periphery.

Description

Technical Field

[0001] This utility model relates to the field of cylindrical workpiece clamping technology, and in particular, to a linkage-type internal support fixing fixture for cylindrical workpieces. Background Technology

[0002] Composite materials are made by combining two or more materials with different properties through physical or chemical methods. They combine the advantages of multiple materials and occupy a key position in modern industry. With the continuous development of composite material technology, their application in aerospace and other fields is becoming increasingly widespread, placing higher demands on the processing accuracy and stability of cylindrical and frustum-shaped composite material workpieces.

[0003] Currently, the most common internal support method in composite material machining is the inflatable bag internal support method. This method utilizes the radial pressure generated by the expansion of a flexible inflatable bag to support and position the inner wall of the workpiece. It is particularly suitable for thin-walled or irregularly shaped hollow workpieces with smooth inner walls and no complex protrusions. An inflatable bag internal support device typically includes an inflatable bag body, an inflation system, a support frame or mandrel, and seals. Its working process mainly includes clamping preparation, inflation, fitting and support, and unloading and removing the workpiece. The workpiece is fixed by converting gas pressure into flexible radial support force.

[0004] However, the internal support method using inflatable bags has significant limitations. Because the inflatable bag material is soft and has poor impact and cut resistance, when the workpiece sidewall has holes or windows to be machined, the rotation, feeding, and cutting actions of the tool during machining can easily scratch or puncture the inflatable bag, leading to problems such as air leakage, decreased support rigidity, workpiece positioning misalignment, and support failure. This not only causes production interruptions, wasting time and materials, but may also affect machine tool accuracy or even cause safety accidents if fragments from a broken inflatable bag are caught in the machining equipment. Utility Model Content

[0005] This utility model provides a linkage-type internal support fixing fixture for cylindrical workpieces, which can adapt to the inner wall structure of cylindrical and frustum-shaped composite material workpieces, and has both flexible fitting characteristics and high rigidity support capacity, so as to solve the technical problem of insufficient reliability of existing inflatable bag internal support methods when processing workpieces with holes or windows.

[0006] This utility model provides a linkage-type internal support fixing fixture for cylindrical workpieces, including a base, a support column, a fixing component, a top annular slider, and an internal support component. The support column is arranged on the base, and the support column is provided with the fixing component, the top annular slider, and a driving mechanism. There are two sets of fixing components, which are arranged at intervals and close to the base. The top annular slider is slidably sleeved on the support column and arranged close to the free end of the support column. The power output end of the driving mechanism is connected to the top annular slider and drives the top annular slider to move along the axial direction of the support column. The internal support component is rotatably connected to the two sets of fixing components through a first link and combined to form a four-bar linkage. The internal support component is rotatably connected to the top annular slider through a second link. There are multiple sets of internal support components, which are arranged at equal intervals along the circumference of the support column.

[0007] Furthermore, the fixing assembly includes a fixing ring fixed to the support column; the first set of fixing rings of the first set of fixing assemblies and the second set of fixing rings of the second set of fixing assemblies are arranged at intervals; the first end of the first link is rotatably connected to the fixing ring, and the second end of the first link is rotatably connected to the inner support assembly.

[0008] Furthermore, the fixing components include a fixing ring slider and a limiting sleeve; the first set of fixing ring sliders and the limiting sleeve of the first set of fixing components and the second set of fixing ring sliders of the second set of fixing components are sequentially sleeved on the support column. The first set of fixing ring sliders is arranged close to the base and abuts against the step portion on the support column. The second set of fixing ring sliders is arranged away from the base and is spaced apart from the first set of fixing ring sliders via the limiting sleeve.

[0009] Furthermore, the first connecting rods of the first set of fixing components and the second set of fixing components have the same length, and the first connecting rods of the first set of fixing components and the second set of fixing components are arranged in parallel.

[0010] Furthermore, the first link and the second link may have the same or different lengths; the extensions of the first link and the second link are arranged to intersect.

[0011] Furthermore, a guide mechanism is provided between the top annular slider and the support column, and the guide direction of the guide mechanism is arranged in the same direction as the axial direction of the support column.

[0012] Furthermore, the internal support assembly includes a support plate and a flexible dot matrix device; the first link and the second link are rotatably connected to the corresponding support plate, and the flexible dot matrix device is arranged on the outside of the support plate.

[0013] Furthermore, the flexible dot matrix device includes a support frame, flexible ejector pins, and ejector pin fixing components. The flexible ejector pins are arranged in an array throughout the inner cavity of the support frame, and the ejector pin fixing components abut and fix the flexible ejector pins inside the support frame. One end of the flexible ejector pin protrudes outside the support frame and is used to abut and fix it to the inner wall surface of the cylindrical workpiece.

[0014] Furthermore, the internal support assembly includes a support plate and a silicone plate, with the silicone plate hinged to the support plate at its center.

[0015] Furthermore, the drive mechanism adopts a threaded sleeve that is threaded to the end of the support column, and the threaded sleeve is rotatably connected to the top annular slider; or the drive mechanism adopts a cylinder or hydraulic cylinder fixed to the end of the support rod, the power output direction of the cylinder or hydraulic cylinder is arranged in the same direction as the axial direction of the support rod, and the power output end of the cylinder or hydraulic cylinder is connected to the top annular slider.

[0016] This utility model has the following beneficial effects: 1. Significantly improves the reliability and safety of the machining process: The support function is achieved through a completely rigid mechanical structure (base, support column, connecting rod, internal support assembly), eliminating the risk of the air bag breaking or leaking due to scraping by the tool, which would lead to support failure. It is particularly suitable for machining cylindrical workpieces with openings such as holes or windows on the side wall. The tool can pass through the openings on the side wall of the workpiece without any obstruction, without worrying about damaging the tooling body, thus ensuring the continuity and stability of the machining process, while avoiding equipment damage or safety accidents caused by fragments generated by the broken air bag.

[0017] 2. Provides excellent structural rigidity and support stability: The mechanical linkage mechanism can provide rigid support far exceeding that of an inflatable bag; when the drive mechanism pushes the top annular slider downward, the second linkage forces the inner support assembly to expand outward until it is tightly fitted with the inner wall of the workpiece. In this state, the workpiece's gravity is transmitted to the base through the robust linkage mechanism and support column, forming a rigid closed-loop force path, which can effectively resist the vibration and deformation caused by the cutting force. This solves the problems of poor clamping stability and easy shaking or even tool vibration, thus providing a solid foundation for high-precision machining (such as boring and milling) and ensuring machining quality.

[0018] 3. Excellent adaptability and dimensional applicability: Multiple sets of circumferentially spaced internal support components are driven by independent linkage systems, forming multiple parallel four-bar linkages. Each internal support component can independently adapt to minor shape errors or out-of-roundness of the workpiece's inner wall within a certain range, ensuring that each support point can effectively contact and apply force, achieving a uniform clamping force distribution and preventing workpiece deformation due to excessive local stress. By controlling the stroke of the top annular slider through the drive mechanism, the radial extension of all internal support components can be steplessly adjusted, allowing one set of tooling to adapt to cylindrical workpieces of different diameters within a certain size range, thus improving the tooling's versatility.

[0019] 4. Achieve precise and synchronous radial motion control: The drive mechanism (such as a threaded sleeve, hydraulic cylinder, pneumatic cylinder, or servo motor driven lead screw) can precisely control the axial displacement of the top annular slider. This axial displacement is synchronously and linearly converted into the radial motion of all inner support components through the linkage mechanism, so that the expansion and contraction of all support points are synchronized. This ensures that the workpiece is correctly positioned and clamped by the inner cavity and achieves automatic centering, avoiding processing errors caused by misalignment during clamping. This precise control capability is difficult to achieve with purely flexible inflatable bags.

[0020] In addition to the objectives, features, and advantages described above, this utility model has other objectives, features, and advantages. The present utility model will now be described in further detail with reference to the figures. Attached Figure Description

[0021] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings: Figure 1 This is a schematic diagram of the structure of a connecting rod type internal support fixing fixture for cylindrical workpieces according to a preferred embodiment of this utility model; Figure 2 This is a schematic diagram of the structure of the flexible dot matrix device according to a preferred embodiment of the present invention.

[0022] Legend: 1. Base; 2. Support column; 3. Top annular slider; 4. Drive mechanism; 5. First connecting rod; 6. Second connecting rod; 7. Fixed annular slider; 8. Limiting sleeve; 9. Support plate; 10. Flexible dot matrix device; 11. Support frame; 12. Flexible ejector pin; 13. Ejector pin fixing component; 14. Threaded sleeve. Detailed Implementation

[0023] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0024] like Figure 1As shown, the linkage-type internal support fixing fixture for cylindrical workpieces in this embodiment includes a base 1, a support column 2, a fixing component, a top annular slider 3, and an internal support component. The support column 2 is arranged on the base 1, and the support column 2 is provided with the fixing component, the top annular slider 3, and the driving mechanism 4. There are two sets of fixing components, which are arranged at intervals and close to the base 1. The top annular slider 3 is slidably sleeved on the support column 2 and arranged close to the free end of the support column 2. The power output end of the driving mechanism 4 is connected to the top annular slider 3 and drives the top annular slider 3 to move along the axial direction of the support column 2. The internal support component is rotatably connected to the two sets of fixing components through the first connecting rod 5 and combined to form a four-bar linkage mechanism. The internal support component is rotatably connected to the top annular slider 3 through the second connecting rod 6. There are multiple sets of internal support components, which are arranged at equal intervals along the circumference of the support column 2. This utility model is a linkage-type internal support fixing fixture for cylindrical workpieces. It achieves the support function through a completely rigid mechanical structure (base 1, support column 2, linkage, internal support assembly), eliminating the risk of support failure caused by the air bag breaking and leaking due to scraping by the tool. It is particularly suitable for processing cylindrical workpieces with openings such as holes and windows on the side wall. The tool can pass through the openings on the side wall of the workpiece without obstruction and without worrying about damaging the fixture body, thus ensuring the continuity and stability of the processing process. At the same time, it avoids equipment damage or safety accidents caused by fragments generated by the broken air bag. The mechanical linkage mechanism can provide rigid support far exceeding that of an inflatable bag. When the drive mechanism 4 pushes the top annular slider 3 downward, the second linkage 6 forces the inner support assembly to expand outward until it is tightly fitted with the inner wall of the workpiece. In this state, the workpiece's gravity is transmitted to the base 1 through the robust linkage mechanism and support column 2, forming a rigid closed-loop force path. This effectively resists the vibration and deformation caused by the cutting force, solving the problems of poor clamping stability and easy shaking or even tool vibration. This provides a solid foundation for high-precision machining (such as boring and milling) and ensures machining quality. Multiple sets of circumferentially spaced internal support components are driven by independent linkage systems, forming multiple parallel four-bar linkages. Each internal support component is allowed to independently adapt to minor shape errors or non-roundness of the workpiece's inner wall within a certain range, ensuring that each support point can effectively contact and apply force, achieving a uniform clamping force distribution and preventing workpiece deformation due to excessive local stress. By controlling the stroke of the top annular slider 3 through the drive mechanism 4, the radial extension of all internal support components can be steplessly adjusted, enabling a set of tooling to adapt to cylindrical workpieces of different diameters within a certain size range, thus improving the tooling's versatility.The drive mechanism 4 (such as threaded sleeve 14, hydraulic cylinder, pneumatic cylinder, or servo motor driven lead screw) can precisely control the axial displacement of the top annular slider 3. This axial displacement is synchronously and linearly converted into the radial movement of all inner support components through the linkage mechanism, so that the expansion and contraction of all support points are synchronized. This ensures that the workpiece is correctly positioned and clamped from the inner cavity and achieves automatic centering, avoiding processing errors caused by misalignment during clamping. This precise control capability is difficult to achieve with purely flexible inflatable bags. This utility model is a linkage-type inner support fixing fixture for cylindrical workpieces. Through a rigid mechanical linkage and slider combination structure, it replaces the traditional inflatable bag solution, solving the core pain points of easy fixture damage and insufficient support rigidity when processing cylindrical workpieces with holes. It comprehensively provides higher reliability, excellent support rigidity, good self-aligning capability, and precise synchronous control, effectively ensuring the processing accuracy, stability, and operational safety of workpieces, especially composite material workpieces. At the same time, it can adapt to workpieces of different sizes, expanding the applicability of the fixture.

[0025] In this embodiment, the fixing component includes a fixing ring fixed to the support column 2; the first set of fixing rings of the first set of fixing components and the second set of fixing rings of the second set of fixing components are arranged at intervals; the first end of the first connecting rod 5 is rotatably connected to the fixing ring, and the second end of the first connecting rod 5 is rotatably connected to the inner support component. The fixing ring is fixed to the support column 2, providing a robust, reliable, and precisely positioned fixing hinge point for the first connecting rod 5; when the inner support component is subjected to the reaction force or cutting force of the workpiece, the force is directly transmitted to the fixing ring through the first connecting rod 5, and then to the base 1 through the support column 2; the two spaced fixing rings cooperate with the two sets of first connecting rods 5, which are equivalent to providing two lower support points for each inner support component, together with the upper support point provided by the top annular slider 3, to form a stable three-dimensional statically determinate support system, enhancing the entire tooling's ability to resist lateral forces and torsional moments, effectively preventing uncontrollable deflection or vibration of the inner support component when subjected to force, thereby ensuring superior rigidity and stability during the processing. The fixed ring precisely constrains the spatial position of the lower hinge point of the first link 5. Since the fixed ends of all the first links 5 are connected to the ring with an unchanging position, it ensures that the coordinates of each hinge point are constant. This unchanging coordinate point, together with the hinge point on the movable top annular slider 3, strictly defines the motion trajectory of the second link 6 and the inner support assembly. When all the inner support assemblies expand and contract, their kinematic behavior is highly consistent and synchronous. This precise movement guaranteed by the mechanical structure itself makes the repeatability of the tooling's positioning accuracy extremely high for each action, which in turn helps to ensure the consistency of batch-processed workpieces. The design of two spaced fixed rings creates two hinge points at the connection point between the first connecting rod 5 and the inner support assembly, effectively providing a double-swing arm lower support structure for the inner support assembly. This structure allows the inner support assembly to have slight self-adjustment capabilities when in contact with the inner wall of the workpiece. If there is slight out-of-roundness or shape error in the inner wall of the workpiece, the inner support assembly can adjust its angle by slightly rotating the two first connecting rods 5, thereby allowing the surface of the inner support block to better fit the workpiece, achieving uniform force distribution and avoiding local stress concentration or deformation of the workpiece caused by three-point contact. The ring structure allows it to be fitted onto and fixed to the support column 2, making full use of the circumferential space of the support column 2, resulting in a very compact structure. The ring structure itself has good bending and torsional resistance, capable of withstanding forces from multiple circumferential connecting rods in different directions, and effectively converging and transferring these forces to the support column 2, ensuring the load-bearing capacity and reliability of the structure.

[0026] like Figure 1As shown, in this embodiment, the fixing component includes a fixing ring slider 7 and a limiting sleeve 8; the first fixing ring slider 7 and the limiting sleeve 8 of the first fixing component and the second fixing ring slider 7 of the second fixing component are sequentially sleeved on the support column 2. The first fixing ring slider 7 is arranged close to the base 1 and abuts against the step portion on the support column 2. The second fixing ring slider 7 is arranged away from the base 1 and is arranged at intervals with the first fixing ring slider 7 through the limiting sleeve 8. By using fixed annular sliders 7 (which can slide but act as fixed fulcrums after being locked by limiting sleeves 8 and stepped parts) instead of welded or fixed rings, and in conjunction with limiting sleeves 8, the axial distance between the two fixed hinge points (i.e. the two fixed annular sliders 7) on the support column 2 becomes an adjustable parameter. By replacing limiting sleeves 8 of different lengths or adjusting the combination of multiple limiting sleeves 8, the user can change the relative position between the two fixed annular sliders 7. This distance directly determines the motion characteristics of the four-bar linkage, i.e. the motion curve and mechanical gain effect of the inner support component when it expands radially. This allows the same tooling to be optimized to adapt to cylindrical workpieces of different heights, different tapers (such as frustum cylindrical shapes), or different rigidity requirements by simply replacing the limiting sleeves 8, achieving multi-purpose use of one tooling, greatly expanding the application range of the tooling, and reducing the cost of customizing special tooling for different workpieces. Although the hinge point position is adjustable, this design provides a solid and reliable axial connection for the fixed annular slider 7 through the stepped portion on the support column 2 and the limiting sleeve 8. When locked, the fixed annular slider 7, the limiting sleeve 8, and the stepped portion of the support column 2 together form a rigid whole. Its function as a fixed hinge point is no different from that of a welded fixed ring, ensuring that the force flow is effectively and stably transmitted to the base 1. This avoids the stiffness reduction or clearance problems that may be introduced by using a sliding structure, and ensures the support rigidity of the tooling in the working state. Fixed rings usually need to be precisely welded to the support column 2 or use an interference fit, which requires high manufacturing and assembly precision. The fixed annular slider 7 can be a standard sleeve-type part, and the limiting sleeve 8 is a simple standard ring-shaped part, which is easy to mass-produce. During assembly, it is only necessary to put it into the support column 2 in sequence and adjust it to the required spacing through the limiting sleeve 8, avoiding the steps of precision machining or welding of the support column 2, simplifying the process flow, reducing manufacturing costs and assembly complexity. The adjustable structure combination of the fixed annular slider 7 and the limiting sleeve 8 can be used to quickly verify the influence of different hinge point positions on clamping force and motion characteristics through experiments, thereby finding the optimal support curve for a specific workpiece and achieving the best clamping effect.

[0027] like Figure 1As shown, in this embodiment, the first connecting rod 5 of the first group of fixing components and the second group of fixing components are of the same length, and the first connecting rod 5 of the first group of fixing components and the second group of fixing components are arranged in parallel. When the two groups of equal-length first connecting rods 5 remain parallel, they, together with the inner support components and the two fixed hinge points, constitute a parallel four-bar linkage. The inner support components only translate during the movement and do not rotate. Regardless of whether the inner support components are in a contracted or expanded state, the support surface used to contact the inner wall of the workpiece always maintains the same posture (i.e., parallel to the axis of the support column 2), ensuring precise centering. All inner support components move synchronously in a radial straight line, perfectly converting the axial movement of the drive slider into radial movement, ensuring the coaxiality of the workpiece axis and the tooling axis when the workpiece is supported, greatly improving the positioning accuracy; ensuring uniform contact, the support surface of the inner support components can maintain parallel contact with the inner wall of the workpiece with the maximum area throughout the entire stroke, avoiding line contact or point contact, thereby providing a stable and uniform support force distribution, effectively preventing the workpiece from deforming due to uneven clamping force. In non-parallel linkage mechanisms, the force of the linkages may generate a component force that causes the inner support assembly to rotate. This component force leads to additional friction and bending moment at the hinge point, which is a harmful internal force. However, the parallel, equal-length design ensures that the two first linkages 5 always bear pure axial tension or compression. The force transmission path is direct and efficient, with all forces used to drive the inner support assembly radially, without generating bending or torque moments in the inner support assembly itself or at the hinge point. This reduces unnecessary energy loss and structural stress, improves the rigidity and transmission efficiency of the mechanism, and extends the service life of moving parts such as hinge pins. The parallel double-link design provides symmetrical and balanced constraints for the inner support assembly. This symmetry gives the mechanism stronger anti-interference capabilities when subjected to asymmetrical cutting forces or reaction forces from the workpiece, effectively suppressing any minor swaying or torsional deformation that may occur in the inner support assembly, thus ensuring extreme stability and reliability of the support state throughout the entire machining process. The equal length and parallelism of the connecting rods simplify the design, size calculation and manufacturing process. All first connecting rods 5 can be mass-produced with the same specifications and dimensions, which reduces manufacturing costs and assembly difficulty, and also facilitates later maintenance and parts replacement.

[0028] like Figure 1As shown, in this embodiment, the lengths of the first link 5 and the second link 6 may be the same or different; the extension lines of the first link 5 and the second link 6 are arranged intersectingly. The length ratio (L1 / L2) of the first link 5 and the second link 6, as well as their initial installation angle, jointly determine the proportional relationship (i.e., transmission ratio) and mechanical gain between the radial displacement of the inner support assembly and the axial displacement of the top annular slider 3. When L1≠L2, the motion curve of the inner support assembly can be precisely customized by adjusting the length ratio of the two links. For example, an expansion strategy of "fast first, slow later" or "slow first, fast later" can be adopted to adapt to the clamping requirements of different workpieces. According to the lever principle, different link ratios also mean different force transmission relationships, which can achieve a force amplification effect (sacrificing displacement to amplify output force) or a range extension effect (sacrificing output force to amplify displacement), thereby matching the output characteristics of different drive mechanisms 4 with the clamping force required by the workpiece. When L1=L2, this is a special symmetry case, which may bring specific motion characteristics under certain symmetrical geometric layouts. However, this solution is not limited to this and retains design flexibility. This solution should avoid the first link 5 and the second link 6 becoming parallel. This can be achieved by setting limit blocks, limit pins, tie rods, or other structures to prevent the first link 5 and the second link 6 from becoming parallel. The condition that the extension lines of the first link 5 and the second link 6 intersect ensures that the entire hinged four-bar linkage has a definite motion, making the first link 5 and the second link 6 non-parallel. Thus, together with the inner support component, the fixed component, and the sliding component, it constitutes an effective and special hinged four-bar linkage. The existence of this intersection point is a prerequisite for the mechanism to move normally and convert the linear motion of the sliding component into the radial motion of the inner support component. Without this condition, the mechanism may not be able to move or may be in an uncertain motion state, or even lead to structural instability. By carefully designing the length and initial angle of the connecting rods, the mechanism can ensure that when the support is in place (the inner support assembly expands to its maximum working position), the hinge point between the first connecting rod 5 and the second connecting rod 6 crosses the "dead point" (i.e., the position where the two connecting rods are collinear). Once the dead point is crossed, the force of the workpiece pressing inward against the inner support assembly will attempt to further lock the mechanism, rather than retract it. This adds a mechanical self-locking function to the tooling, greatly enhancing the reliability and safety of clamping. Even if the drive source fails unexpectedly, the workpiece will not loosen, making it particularly suitable for heavy cutting or high-vibration machining scenarios. The non-equal length and intersecting connecting rod design can generate a non-linear motion trajectory. Through optimized design, the motion trajectory of the end of the inner support assembly can better match the inner wall contour of a workpiece with a specific taper (such as a frustum), achieving continuous and uniform contact between the support block and the inner wall of the workpiece, rather than point or line contact, thus providing superior support stability and load-bearing capacity.

[0029] like Figure 1As shown, in this embodiment, a guide mechanism is provided between the top annular slider 3 and the support column 2. The guide direction of the guide mechanism is arranged in the same direction as the axial direction of the support column 2. By constraining the motion freedom of the top annular slider 3 through the guide mechanism, it can only perform precise linear motion along the axial direction of the support column 2, and cannot undergo circumferential rotation or radial offset. This precise pure axial motion is the basis for all subsequent motion conversions, ensuring that the linear output of the drive mechanism 4 is transmitted without deviation. Then, through the second connecting rod 6, all circumferentially arranged inner support components are driven radially in a synchronous and equal manner, thereby achieving high-precision centering (ensuring that the workpiece axis coincides with the tooling axis) and uniform clamping. During tooling clamping and operation, the top annular slider 3 bears radial forces, bending moments, and torques from various directions via a linkage mechanism. If the drive mechanism 4 (such as a cylinder rod or lead screw) alone bears these forces, it is highly susceptible to bending, deformation, accelerated wear, or even failure. Independent guide mechanisms (such as keyway fits, linear guides, or guide sleeves) are specifically designed to withstand these lateral loads. They effectively transfer these harmful forces directly to the robust support column 2, thereby isolating and protecting the precision drive mechanism 4, allowing it to bear only pure axial push and pull forces, significantly improving the reliability and service life of the entire system. High-precision guide mechanisms (such as pre-tensioned linear guides) can effectively eliminate backlash in the kinematic pairs, preventing slight reverse displacement or wobbling of the top annular slider 3 when the cutting force direction changes. This backlash-free rigid connection greatly enhances the dynamic stiffness of the entire tooling system, effectively suppressing vibrations generated during machining and preventing tool vibration, thus ensuring the surface quality and dimensional accuracy of the workpiece. It is particularly suitable for heavy or precision cutting scenarios. Dedicated guiding mechanisms (such as linear bearings or ball bearings) can provide low-friction, high-smoothness motion, reducing the load requirements of the drive mechanism 4, making it run more smoothly and consume less energy.

[0030] like Figure 1As shown, in this embodiment, the inner support assembly includes a support plate 9 and a flexible dot matrix device 10. The first connecting rod 5 and the second connecting rod 6 are rotatably connected to their respective support plates 9, and the flexible dot matrix device 10 is arranged on the outer side of the support plate 9. The support plate 9, as a rigid frame, is hinged to the first connecting rod 5 and the second connecting rod 6, achieving fixation through mutual restraint. It is responsible for bearing and transmitting strong clamping and cutting forces, ensuring that the entire support system has extremely high rigidity and can effectively resist vibration and deformation during processing, providing a solid foundation for precision machining. The flexible dot matrix device 10, as the interface that directly contacts the workpiece, has flexible characteristics that allow it to adaptively conform to the microscopic unevenness or macroscopic shape deviations (such as slight roundness errors or tapers) of the workpiece's inner wall. This conformation ensures maximum contact area, avoiding workpiece indentations, stress concentrations, or localized deformations that may be caused by rigid point or line contact. After being compressed, the flexible dot matrix device 10 undergoes micro-deformation at its multiple contact points to evenly distribute the load, resulting in a more uniform clamping force distribution. This avoids excessive local stress that could damage the workpiece, making it particularly suitable for easily damaged materials such as composite materials. The uniform clamping force, combined with the overall high rigidity, ensures that the workpiece will not move or shift during processing, thereby greatly improving the dimensional accuracy and surface quality of the machining. Traditional rigid supports may scratch or damage the finished surface of the workpiece, while the flexible dot matrix device 10 acts as a buffer or flexible clamp, greatly reducing the risk of damaging the workpiece surface. This protective effect is particularly beneficial for workpieces with high surface quality requirements, relatively soft materials (such as aluminum alloys), or composite materials with low interlayer strength, providing excellent cushioning and protection. The internal support assembly is divided into a support plate 9 and a flexible dot matrix device 10, forming a modular design with multifunctionality and adaptability. The flexible dot matrix device 10 with different hardness, density or material can be replaced according to the material (such as steel, aluminum, composite material) and surface requirements of different workpieces to achieve the best clamping and protection effect, thus expanding the applicability of the tooling. It is also maintainable, as the flexible dot matrix device 10, as a consumable part or working condition adaptable part, can be replaced independently and conveniently without replacing the entire internal support assembly, reducing the later use and maintenance costs.

[0031] like Figure 1 and Figure 2As shown, in this embodiment, the flexible dot matrix device 10 includes a support frame 11, flexible ejector pins 12, and ejector pin fixing member 13. The flexible ejector pins 12 are arranged in an array to fill the inner cavity of the support frame 11. The ejector pin fixing member 13 abuts and fixes the flexible ejector pins 12 inside the support frame 11. One end of the flexible ejector pin 12 protrudes outside the support frame 11 and is used to abut and fix with the inner wall surface of the cylindrical workpiece. A large flexible contact surface is discretized into a large number of independently acting "flexible ejector pins 12" units; the support frame 11 provides a robust mounting base, ensuring that the entire device can be reliably connected to the support plate 9 as a whole and withstand the main force from the support plate 9, thus ensuring the overall structural rigidity; each flexible ejector pin 12 in the array is an independent buffer elastic unit that can independently extend and retract to compensate for local micro-irregularities in the inner wall of the workpiece; this "matrix" contact ensures that even if there are shape errors or local depressions in the inner wall of the workpiece, a large number of flexible ejector pins 12 can still make effective contact with it, thereby achieving a very high and uniform surface contact effect and avoiding local suspension or stress concentration. Because each flexible ejector pin 12 can independently respond to the local pressure at its location, the device has an automatic load-sharing function. When there is a slight bulge on the inner wall of the workpiece, the flexible ejector pin 12 in that location experiences greater compression and a stronger reaction force. In concave areas, the flexible ejector pin 12 experiences less compression and a smaller force. This adaptive characteristic makes the pressure distribution on the entire contact surface highly uniform, effectively preventing damage such as indentations, pinching, or interlayer delamination on thin-walled or soft material workpieces (such as composite materials), providing unprecedented workpiece protection. The entire flexible dot matrix device 10 is a standalone module connected to the support plate 9 via the support frame 11, allowing it to be replaced as a whole for different workpiece materials, precision requirements, and surface characteristics. For example, ejector pin modules with different hardness, diameters, or distribution densities can be equipped to optimize the clamping effect. If individual flexible ejector pins 12 are damaged due to long-term use or accidental impact, they can be partially replaced by disassembling the ejector pin fixing part 13 without discarding the entire device, significantly reducing long-term maintenance costs. Compared to a complete solid flexible pad, the dot matrix composed of a large number of flexible ejector pins 12 has natural gaps between it. These gaps form good heat dissipation channels, which is conducive to the dissipation of cutting heat and avoids excessive heat accumulation that may affect the workpiece accuracy or damage the tooling. When machining workpieces with holes, these gaps also facilitate the discharge of cutting chips, preventing chips from accumulating between the workpiece and the tooling and affecting the positioning accuracy or scratching the workpiece surface.

[0032] In this embodiment, the inner support assembly includes a support plate 9 and a silicone plate, with the middle portion of the silicone plate hinged to the support plate 9. Hinging the middle portion of the silicone plate to the support plate 9 creates an efficient "seesaw" or "rocker arm" mechanism. When there is a height difference between the inner walls of the workpiece contacted on both sides of the silicone plate (e.g., due to the taper, roundness error of the workpiece itself, or installation eccentricity), the silicone plate can tilt slightly around the hinge point in its middle. This tilting motion allows the entire working surface of the silicone plate to quickly and significantly adapt to the overall contour of the inner wall of the workpiece, thereby achieving uniform contact over a large area. Its self-aligning and adaptive effect is very significant and rapid on a macroscopic scale. Compared to the flexible dot matrix device 10, which consists of numerous parts, this solution comprises only a silicone plate and a hinge shaft (or equivalent structure). The structure is extremely simplified, with fewer parts, a simpler assembly process, a lower failure rate, and significantly reduced manufacturing costs. This simplicity makes it highly competitive in cost-sensitive applications. The silicone material itself is soft, has a high coefficient of friction, and excellent damping properties. The soft silicone surface greatly minimizes scratches or pressure damage to the machined surfaces of workpieces or soft materials (such as anodized aluminum and composite materials), providing excellent protection. The good elasticity and damping properties of silicone effectively absorb and attenuate high-frequency vibrations and noise generated during processing, helping to improve the processing environment and, to some extent, enhance the quality of the processed surface. Despite its simple structure, the central hinge design, combined with the elasticity of the silicone plate, can balance the pressure on both sides of the silicone plate to a certain extent. When one side is subjected to greater pressure, the lever effect of the hinge point will compensate for the other side. Combined with the deformation of the silicone itself, this helps to achieve a relatively uniform pressure distribution overall, avoiding extremely localized stress concentration points.

[0033] like Figure 1As shown, in this embodiment, the drive mechanism 4 uses a threaded sleeve 14 threaded to the end of the support column 2. The threaded sleeve 14 and the top annular slider 3 are rotatably connected. Alternatively, the drive mechanism 4 uses a cylinder or hydraulic cylinder fixed to the end of the support rod. The power output direction of the cylinder or hydraulic cylinder is the same as the axial direction of the support rod, and the power output end of the cylinder or hydraulic cylinder is connected to the top annular slider 3. Using a threaded pair (threaded sleeve 14 and the thread at the end of the support column 2) as the drive core, it has inherent mechanical self-locking characteristics. When the drive stops, the system can automatically maintain its position and clamping state without continuous external energy input, and will not loosen due to workpiece reaction force or vibration. This self-locking capability greatly enhances the safety and reliability of the tooling, and is particularly suitable for long-term processing or situations where energy is interrupted. Threaded transmission is a precise linear transmission method. By rotating the threaded sleeve 14, a very small and precise axial displacement can be obtained, thereby realizing high-precision fine adjustment and stepless control of the radial expansion of the inner support component. This makes it easy for the operator to finely adjust the clamping force to perfectly adapt to workpieces with different tolerances or materials. Eliminating the need for complex power sources and control systems, operation is achieved simply by rotating the threaded sleeve 14 manually or with a tool. Its simple and compact structure results in low manufacturing and maintenance costs. Using a pneumatic or hydraulic cylinder as the power source, it can be easily integrated with modern CNC or PLC control systems to achieve fully automated clamping and releasing operations. This significantly reduces workpiece clamping time, making it particularly suitable for high-volume, high-cycle production lines, and significantly improving production efficiency. For pneumatic cylinders (in conjunction with pneumatic triplet units) or hydraulic cylinders (in conjunction with hydraulic systems), the output force—the thrust applied to the top annular slider 3—can be directly and linearly set and controlled by adjusting the fluid pressure. This allows for a preset, constant clamping force on the workpiece, preventing over-clamping damage or insufficient clamping leading to loosening. The control is highly precise and intuitive. Fluid-driven methods such as pneumatic cylinders and hydraulic cylinders typically offer faster movement speeds, enabling rapid opening and closing of tooling. Pneumatic and hydraulic cylinders are also prone to achieving longer strokes, allowing the inner support assembly to have a larger radial adjustment range, enabling the tooling to adapt to workpieces with greater diameter differences. Both designs clearly define the direction of the driving force as being in the same direction as the axis of the support column 2, which ensures efficient transmission of the driving force, avoids lateral force components, and guarantees the smoothness and accuracy of the mechanism's movement.

[0034] Compared with traditional technologies, the linkage-type internal support fixing fixture of this utility model for cylindrical workpieces has the following advantages: Compared to traditional inflatable bag internal support fixing methods, this utility model tooling design offers greater stability. Its rigid structure can accommodate workpieces with complex shapes, effectively avoiding rigidity and fixation failure issues caused by gas leakage. Furthermore, the tooling eliminates the need for inflation and deflation operations, allowing for direct assembly and significantly improving workpiece fixation efficiency. It is also reusable, resulting in lower long-term costs and greater environmental friendliness. In addition, the flexible dot matrix device 10 on the support plate 9 precisely fills workpiece gaps, achieving better fit and further reducing the risk of workpiece wobbling during machining.

[0035] Any matters not covered in this utility model are common knowledge.

[0036] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0037] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

[0038] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A linkage-type internal support fixing fixture for cylindrical workpieces, characterized in that, Includes a base (1), a support column (2), a fixing component, a top annular slider (3), and an inner support component; The support column (2) is arranged on the base (1). The support column (2) is provided with a fixing component, a top annular slider (3) and a drive mechanism (4). There are two sets of fixing components. The two sets of fixing components are arranged at intervals and close to the base (1). The top annular slider (3) is slidably sleeved on the support column (2) and arranged close to the free end of the support column (2). The power output end of the drive mechanism (4) is connected to the top annular slider (3) and drives the top annular slider (3) to move along the axial direction of the support column (2). The inner support components are rotatably connected to the two sets of fixed components through the first link (5) and combined to form a four-bar linkage. The inner support components are rotatably connected to the top annular slider (3) through the second link (6). There are multiple sets of internal support components, and the multiple sets of internal support components are arranged at equal intervals along the circumference of the support column (2).

2. The linkage-type internal support fixing fixture for cylindrical workpieces according to claim 1, characterized in that, The fixing components include a fixing ring fixed to the support column (2); The first set of fixing rings of the first set of fixing components and the second set of fixing rings of the second set of fixing components are arranged at intervals. The first end of the first link (5) is rotatably connected to the fixed ring, and the second end of the first link (5) is rotatably connected to the inner support assembly.

3. The linkage-type internal support fixing fixture for cylindrical workpieces according to claim 1, characterized in that, The fixing components include a fixing annular slider (7) and a limiting sleeve (8); The first set of fixing ring sliders (7) of the first set of fixing components, the limiting sleeve (8), and the second set of fixing ring sliders (7) of the second set of fixing components are sequentially sleeved on the support column (2). The first set of fixing ring sliders (7) is arranged close to the base (1) and abuts against the step on the support column (2). The second set of fixing ring sliders (7) is arranged away from the base (1) and is arranged at intervals with the first set of fixing ring sliders (7) through the limiting sleeve (8).

4. The linkage-type internal support fixing fixture for cylindrical workpieces according to claim 1, characterized in that, The first connecting rod (5) of the first group of fixing components and the second group of fixing components are of the same length, and the first connecting rod (5) of the first group of fixing components and the second group of fixing components are arranged in parallel.

5. The linkage-type internal support fixing fixture for cylindrical workpieces according to claim 1, characterized in that, The first link (5) and the second link (6) may have the same or different lengths; The extensions of the first link (5) and the second link (6) are arranged to intersect.

6. The linkage-type internal support fixing fixture for cylindrical workpieces according to claim 1, characterized in that, A guide mechanism is provided between the top annular slider (3) and the support column (2), and the guide direction of the guide mechanism is arranged in the same direction as the axial direction of the support column (2).

7. The linkage-type internal support fixing fixture for cylindrical workpieces according to any one of claims 1 to 6, characterized in that, The internal support components include a support plate (9) and a flexible dot matrix device (10). The first link (5) and the second link (6) are rotatably connected to the corresponding support plate (9), and the flexible dot matrix device (10) is arranged on the outside of the support plate (9).

8. The linkage-type internal support fixing fixture for cylindrical workpieces according to claim 7, characterized in that, The flexible dot matrix device (10) includes a support frame (11), flexible ejector pins (12) and ejector pin fixing member (13). The flexible ejector pins (12) are arranged in an array to fill the inner cavity of the support frame (11). The ejector pin fixing member (13) presses and fixes the flexible ejector pins (12) inside the support frame (11). One end of the flexible ejector pin (12) protrudes outside the support frame (11) and is used to abut and fix against the inner wall surface of the cylindrical workpiece.

9. The linkage-type internal support fixing fixture for cylindrical workpieces according to any one of claims 1 to 6, characterized in that, The internal support assembly includes a support plate (9) and a silicone plate, with the middle part of the silicone plate hinged and fixed to the support plate (9).

10. The linkage-type internal support fixing fixture for cylindrical workpieces according to any one of claims 1 to 6, characterized in that, The drive mechanism (4) is connected to a threaded sleeve (14) at the end of the support column (2) by a thread. The threaded sleeve (14) and the top annular slider (3) are rotatably connected and arranged; or The drive mechanism (4) adopts a cylinder or oil cylinder fixed to the end of the support rod. The power output direction of the cylinder or oil cylinder is arranged in the same direction as the axial direction of the support rod. The power output end of the cylinder or oil cylinder is connected to the top annular slider (3).

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