A deformation prevention constraint tool for milling inner cavity of workpiece

Abstract

The present application relates to a kind of anti-deformation constraint tool for workpiece inner cavity milling, for solving the technical problem of poor machining precision caused by the deformation of workpiece in machining in prior art, the device includes positioning table, first constraint component, inner cavity pressing plate and base table;Positioning table is set on machine tool worktable by base table;First constraint component is set on positioning table, and first constraint component is from the position constraint of workpiece to workpiece outer periphery;Inner cavity pressing plate is set on positioning table and abuts the bottom inner wall of workpiece.The first constraint component and inner cavity pressing plate provide support, so that the ability of workpiece in resisting deformation is enhanced, the large-area contact of first constraint component and workpiece outer wall increases the contact damping of workpiece, this damping can effectively dissipate vibration energy, prevent the amplification of vibration, thereby, the deformation of workpiece in machining can be reduced, and the forming quality of workpiece is improved.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and in particular to a deformation-resistant constraint fixture for milling the inner cavity of a workpiece. Background Technology

[0002] In milling internal cavities of workpieces, the rigidity is often limited due to the inherent characteristics of the cavity structure. After undergoing the preceding turning process, the workpiece is prone to initial deformation due to stress release, such as excessive ellipticity or slight warping. When entering the milling clamping stage, existing technologies typically use chucks or other fixtures to position and secure the workpiece. These clamping methods often involve localized point or line contact, making it difficult to form a uniform and stable envelope support. This clamping method easily leads to stress concentration near the clamping point, causing additional radial or axial deformation of the workpiece.

[0003] During the subsequent internal milling process, the milling cutter cuts within a closed space, and the direction and magnitude of its cutting force continuously change. Due to the lack of effective full circumferential constraint on the workpiece, the problem of insufficient local rigidity is amplified under the action of dynamic cutting force, which easily leads to machining vibration and "tool deflection" phenomenon, resulting in poor workpiece forming quality. Summary of the Invention

[0004] The purpose of this invention is to provide a deformation-resistant constraint fixture for milling the inner cavity of a workpiece, so as to solve the technical problem of poor workpiece forming quality caused by insufficient local rigidity of the workpiece in the prior art.

[0005] The objective of this invention is mainly achieved through the following technical solutions:

[0006] In one aspect, a deformation-resistant constraint fixture for milling the inner cavity of a workpiece is provided, comprising a positioning table, a first constraint assembly, an inner cavity clamping plate, and a base table;

[0007] The positioning table is fixedly mounted on the base platform, and the base platform is movable on the machine tool worktable; the first constraint component is mounted on the positioning table, and the first constraint component constrains the position of the workpiece from the outer periphery of the workpiece; the inner cavity clamping plate is mounted on the positioning table and abuts against the bottom inner wall of the workpiece to constrain the position of the bottom of the workpiece from the inside of the workpiece.

[0008] Furthermore, it also includes a height adjustment block, which is placed between the positioning platform and the base platform to adjust the height of the positioning platform and to provide a space for accommodation between the positioning platform and the base platform.

[0009] Furthermore, a first chip outlet hole is provided on the positioning platform to allow chips from the inner cavity of the workpiece to flow out of the inner cavity of the workpiece.

[0010] Furthermore, a second chip outlet hole is provided on the inner cavity clamping plate.

[0011] Furthermore, the first constraint component includes multiple constraint units, which constrain the position of a portion of the workpiece from its outer periphery.

[0012] Furthermore, the constraint unit includes a constraint unit, a constraint plate, and a weight-reducing groove. The constraint plate is located on the constraint unit and abuts against the workpiece. The weight-reducing groove is formed on the constraint plate to reduce the weight of the constraint plate.

[0013] Furthermore, the constraint unit also includes a connecting handle, which is disposed on the constraint unit to connect with adjacent constraint units.

[0014] Furthermore, the first constraint assembly also includes a buffer member, which includes an embedding groove and a buffer strip. The embedding groove is formed on the inner wall of the first constraint assembly, and the buffer strip is embedded in the embedding groove and abuts against the workpiece.

[0015] Furthermore, the positioning platform is also provided with a positioning stop to cooperate with the first constraint component to achieve radial positioning.

[0016] Furthermore, a lifting ring is fixedly installed on the positioning platform to suspend the anti-deformation constraint fixture used for milling the inner cavity of the workpiece.

[0017] In one or more technical solutions provided in the exemplary embodiments of the present invention, at least one of the following beneficial effects can be achieved.

[0018] (1) In the technical solution of the anti-deformation constraint fixture for milling the inner cavity of the workpiece in this invention, the first constraint component and the inner cavity clamping plate provide support, which enhances the workpiece's ability to resist deformation. Under the same cutting force, the amount of elastic deformation generated will be reduced. The large-area contact between the first constraint component and the outer wall of the workpiece, as well as the contact between the inner cavity clamping plate and the inner wall of the workpiece, increase the contact damping of the workpiece. This damping can effectively dissipate vibration energy and prevent the amplification of vibration. Thus, the deformation of the workpiece during the processing can be reduced, and the forming quality of the workpiece can be improved.

[0019] (2) In the technical solution of the anti-deformation constraint fixture for milling the inner cavity of the workpiece in this invention, the constraint plate is designed according to the shape of the workpiece and can fit precisely with the workpiece to directly and stably constrain the workpiece. At the same time, the reduction groove improves the stress distribution of the constraint plate, making the constraint plate more uniformly stressed when holding the workpiece, reducing the workpiece deformation caused by uneven stress, thereby improving the machining accuracy of the workpiece.

[0020] (3) In the technical solution of the anti-deformation constraint fixture for milling the inner cavity of the workpiece in this invention, the buffer strip is embedded in the embedding groove of the inner wall of the first constraint component and abuts against the workpiece. Its flexibility allows it to adapt to the deformation of the workpiece surface. When the first constraint component applies pressure to the workpiece, the buffer strip can evenly distribute the pressure on the contact surface to avoid excessive local pressure. The buffer strip provides uniform and stable support for the workpiece, enhances the workpiece's ability to resist deformation, and thus reduces the amount of "tool deflection".

[0021] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0022] The accompanying drawings illustrate exemplary embodiments of the invention and, together with the description thereof, serve to explain the principles of the invention. These drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification.

[0023] Figure 1 This is a schematic diagram of the anti-deformation constraint tooling used for milling the inner cavity of a workpiece in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of the follow-up clamping assembly in an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the structure of the clamping plate in an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the structure of the second constraint component in an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the structure of the receiving groove in an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the constraint capsule in an embodiment of the present invention;

[0029] Figure 7 This is a schematic diagram of the elastic reset unit in an embodiment of the present invention.

[0030] The attached figures are labeled as follows:

[0031] 1-Positioning stage, 11-First chip outlet hole, 2-First constraint assembly, 21-Constraint unit, 210-Constraint unit, 211-Constraint plate, 212-Relief groove, 213-Connecting handle, 3-Inner cavity clamping plate, 31-Second chip outlet hole, 4-Lifting ring, 5-Second constraint assembly, 51-Oil distribution box, 52-Oil flow pipe, 53-Receiving groove, 531-Receiving groove body, 532-Fixing hole, 54-Constraint bladder, 541-Constraint 542-Bottom support, 543-Spacing plate, 544-Telescopic surface, 545-Elastic reset unit, 546-First support plate, 547-Second support plate, 6-Base platform, 7-Follow-up pressing assembly, 71-Support frame, 72-Follow-up motor, 73-Connecting arm, 74-Telescopic rod, 75-Pressure plate, 751-Pressure plate body, 752-Rigid support block, 753-Flexible support block, 754-Deformation gap, 8-Height adjustment block. Detailed Implementation

[0032] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0033] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments.

[0034] Example 1

[0035] like Figure 1 As shown, Embodiment 1 of the present invention provides an anti-deformation constraint fixture for milling the inner cavity of a workpiece, including a positioning table 1, a first constraint component 2, an inner cavity clamping plate 3, and a base table 6; the positioning table 1 is fixedly mounted on the base table 6, and the base table 6 is movably mounted on the machine tool worktable; the first constraint component 2 is mounted on the positioning table 1, and the first constraint component 2 constrains the position of the workpiece from the outer periphery of the workpiece; the inner cavity clamping plate 3 is mounted on the positioning table 1 and abuts against the bottom inner wall of the workpiece to constrain the position of the bottom of the workpiece from the inside of the workpiece.

[0036] Positioning table 1 provides a stable and reliable mounting platform. It is rigidly connected to base table 6, making positioning table 1 and base table 6 a whole. It can effectively absorb and resist various dynamic loads generated during the processing. This not only ensures the accuracy of the current processing operation, but also provides convenience for subsequent repetitive production. It ensures that each clamping can obtain a consistent reference position, thereby ensuring the consistency of batch workpiece processing.

[0037] The first constraint component 2 is used to achieve radial constraint on the workpiece by clamping it around its outer periphery. This provides a uniform and continuous radial support force to the workpiece, thereby improving the radial rigidity of the workpiece during machining. By having a large-area contact with the outer surface of the workpiece, the first constraint component 2 distributes the clamping force across the entire circumference, avoiding the local stress concentration problem caused by point contact or line contact fixtures such as traditional three-jaw chucks. This uniform constraint force can effectively suppress the radial vibration and deformation of the workpiece under the action of cutting force.

[0038] The inner cavity clamping plate 3 provides axial clamping force and radial support to the bottom inner wall of the workpiece. It cooperates with the radial constraint of the first constraint component. Through the precise cooperation with the bottom inner wall of the workpiece, the inner cavity clamping plate 3 achieves axial positioning and inner support of the workpiece.

[0039] The base table 6 provides a stable support platform for the positioning table 1, enabling the positioning table 1 to be firmly positioned in a specific location, thereby ensuring the stability of the entire tooling structure and laying the foundation for subsequent positioning and constraint operations on the workpiece. At the same time, the base table 6 can be adjusted on the machine tool worktable. By moving the base table 6, the position of the tooling can be changed conveniently and quickly without the need for cumbersome re-clamping operations on the workpiece, thus improving the flexibility and efficiency of processing.

[0040] During machining, the workpiece may undergo elastic deformation under the action of cutting force due to insufficient rigidity, resulting in the actual cutting depth of the tool being less than the theoretical value, thereby affecting the machining dimensional accuracy (this phenomenon is referred to as "tool deflection" in the art). In the technical solution of this embodiment, the first constraint component 2 and the inner cavity clamping plate 3 provide support, thereby enhancing the workpiece's ability to resist deformation. Under the same cutting force, the amount of elastic deformation (i.e., the amount of "tool deflection") will be reduced.

[0041] In addition, due to the structural characteristics of the workpiece, self-excited vibrations (a phenomenon referred to as "chatter" in the art) will occur between the tool and the workpiece during the machining process. Chatter will affect the surface quality of the machined surface and may cause damage to the tool and machine tool. The large-area contact between the first constraint component and the outer wall of the workpiece, as well as the contact between the inner cavity clamping plate and the inner wall of the workpiece, increase the contact damping of the workpiece. This damping can effectively dissipate vibration energy and prevent the vibration from amplifying. At the same time, by enhancing the rigidity of the workpiece, its natural frequency is increased, making it less likely for the excitation frequency of the machining process to coincide with the natural frequency of the workpiece, thereby reducing the occurrence of chatter.

[0042] In summary, based on the above settings, this embodiment can reduce workpiece deformation during processing and improve the workpiece forming quality.

[0043] For example, the workpiece can be a cylindrical shape with a circular, elliptical, or square cross-section, but is not limited thereto.

[0044] In one specific implementation, such as Figure 1 As shown, the anti-deformation constraint fixture for milling the inner cavity of the workpiece also includes a height adjustment block 8. The height adjustment block 8 is placed between the positioning table 1 and the base table 6 to adjust the height of the positioning table 1 and to create a space for accommodating the positioning table 1 and the base table 6.

[0045] In the internal milling of workpieces, different workpieces or different processing stages of the same workpiece may have different requirements for the height of the positioning table 1. By selecting height adjustment blocks 8 of different thicknesses or using multiple height adjustment blocks 8 in combination, the height of the positioning table 1 can be adjusted to meet diverse processing needs. By adjusting the height adjustment blocks 8 to make the positioning table 1 at a suitable height, the workpiece is ensured to be in the optimal position during processing, thereby ensuring milling accuracy. During the internal milling of workpieces, a large amount of chips and heat are generated. The accommodating space can provide a certain discharge channel for the chips, allowing them to be smoothly discharged from the processing area, avoiding chip accumulation inside the fixture, which would affect the normal operation of the fixture and the processing quality. At the same time, this space also facilitates air circulation, helps heat dissipation, and prevents the fixture from overheating due to long-term processing, which could lead to deformation or damage of parts, thus ensuring the accuracy and stability of the fixture.

[0046] In one specific implementation, such as Figure 1 As shown, the positioning table 1 has a first chip outlet hole 11 to allow the chips from the inner cavity of the workpiece to flow out of the inner cavity of the workpiece.

[0047] The first chip outlet hole 11 provides an outlet channel for chips, allowing them to be smoothly discharged from the inner cavity of the workpiece. This avoids chip accumulation and damage to the workpiece surface, ensures the machining quality of the workpiece, reduces the interference of chips on workpiece positioning, and ensures the positioning accuracy of the workpiece during the machining process.

[0048] In one specific embodiment, the inner cavity clamping plate 3 is provided with a second chip outlet hole 31.

[0049] The second chip outlet hole 31 is also used for chip discharge, reducing chip accumulation in the inner cavity.

[0050] In one specific implementation, such as Figure 1 As shown, the first constraint component 2 includes multiple constraint units 21, which constrain the position of a portion of the workpiece from the outer periphery of the workpiece.

[0051] In processing practice, there are often cylindrical structures with irregular shapes. Compared with the single integral first constraint component method, multiple constraint units 21 as the first constraint component can more flexibly adjust the clamping range and force on the workpiece. For some irregularly shaped workpieces or workpieces with special structural requirements, effective position constraints can also be achieved, improving the versatility of the device.

[0052] By working together, the clamping force on the outer periphery of the workpiece can be distributed to each unit, which can avoid excessive local deformation of the workpiece due to excessive local force, and make the clamping force on the workpiece more uniform during the processing, thereby better maintaining the overall shape accuracy of the workpiece.

[0053] In one specific implementation, such as Figure 1 As shown, the constraint unit 21 includes a constraint unit 210, a constraint plate 211, and a weight-reducing groove 212. The constraint plate 211 is located on the constraint unit 210 and abuts against the workpiece. The weight-reducing groove 212 is formed on the constraint plate 211 to reduce the weight of the constraint plate 211.

[0054] The constraint unit 210 provides a foundation for mounting and supporting other components such as the constraint plate 211 and the relief groove 212. Simultaneously, the constraint unit 210 connects and positions with other constraint units 21 and positioning table 1. The constraint plate 211 applies pressure through close contact with the outer periphery of the workpiece, limiting the radial and axial deformation of the workpiece and thus maintaining its shape accuracy. It should be noted that, to accommodate workpieces of different shapes, the shape of the constraint plate 211 needs to be specially designed according to the workpiece's shape to maximize the contact area between the constraint plate 211 and the workpiece, improving the stability and reliability of the constraint. The relief groove 212 is formed on the constraint plate 211 to reduce its weight. The relief groove 212 also improves the stress distribution of the constraint plate 211. When clamping the workpiece, the constraint plate 211 is subjected to certain stress. The relief groove 212 allows the stress to be distributed more evenly on the constraint plate 211, avoiding localized stress concentration, thereby reducing the possibility of damage to the constraint plate 211 due to excessive stress and extending the service life of the constraint unit 21.

[0055] The constraint plate 211 is designed according to the shape of the workpiece, and can fit precisely with the workpiece to directly and stably constrain it. At the same time, the weight reduction groove 212 improves the stress distribution of the constraint plate 211, making the force on the constraint plate 211 more uniform when holding the workpiece, reducing the workpiece deformation caused by uneven stress, thereby improving the machining accuracy of the workpiece and ensuring that the size and shape of the machined workpiece better meet the design requirements. After reducing the weight of the constraint unit 21, the inertia of the device during operation is reduced, and the vibration is also reduced accordingly, improving the constraint accuracy and ensuring the stability of the machining quality.

[0056] In one specific implementation, such as Figure 1 As shown, the constraint unit 21 also includes a connecting handle 213, which is disposed on the constraint unit 210 to connect with the adjacent constraint unit 21.

[0057] The connecting handle 213 is a structure that connects adjacent constraint units 21. Multiple constraint units 21 are connected together by connecting parts such as bolts to form a complete first constraint assembly 2, thereby achieving overall constraint on the workpiece.

[0058] In one specific embodiment, the first constraint component 2 further includes a buffer member, which includes an embedding groove and a buffer strip. The embedding groove is formed on the inner wall of the first constraint component, and the buffer strip is embedded in the embedding groove and abuts against the workpiece.

[0059] The recessed groove is used to accommodate and fix the buffer strip, and its opening direction is facing the outer wall of the workpiece. The buffer strip is used to provide buffering and shock absorption function. The buffer strip is usually made of a material with a certain elasticity, such as rubber or silicone. The buffer strip can absorb and disperse the pressure applied to the workpiece by the first constraint component 2 through its own elastic deformation, so as to play a role in buffering and shock absorption. This helps to reduce the damage to the workpiece caused by excessive clamping force or vibration generated during processing and protect the surface quality of the workpiece.

[0060] In addition, the workpiece may have certain shape errors or uneven surfaces during the manufacturing process. The flexibility of the buffer strip allows it to better adapt to the shape changes of the workpiece, fit tightly against the workpiece surface, increase the contact area, and improve the stability and reliability of the constraint.

[0061] The buffer strip is embedded in the groove on the inner wall of the first constraint component and abuts against the workpiece. Its flexibility allows the buffer strip to adapt to the shape of the workpiece surface. When the first constraint component 2 applies pressure to the workpiece, the buffer strip can evenly distribute the pressure on the contact surface to avoid excessive local pressure. For example, if there are small bumps on the workpiece surface, the buffer strip can be appropriately compressed at the protrusions and fully contacted at the depressions to provide uniform and stable support for the workpiece, enhance the workpiece's ability to resist deformation, and thus reduce the amount of "tool deflection".

[0062] The first constraint component 2 has a large contact area with the outer wall of the workpiece, and the inner cavity clamping plate 3 has a contact area with the inner wall of the workpiece. The buffer strip further increases the tightness and complexity of this contact. The friction between the buffer strip and the surface of the workpiece, as well as its own elastic deformation, can increase the contact damping. When vibration occurs, the contact damping can convert the vibration energy into heat energy and other forms of energy to dissipate, prevent the amplification of vibration, and thus suppress the generation and development of flutter.

[0063] In one specific embodiment, the positioning stage 1 is further provided with a positioning stop to cooperate with the first constraint component 2 to achieve radial positioning.

[0064] In one specific implementation, such as Figure 1 As shown, a lifting ring 4 is also fixedly installed on the positioning table 1 and / or the first constraint assembly 2 to lift the anti-deformation constraint fixture used for milling the inner cavity of the workpiece.

[0065] The lifting ring 4 is a component used for lifting. It is fixed on the positioning platform 1 and / or the first constraint assembly 2, providing a clear point of force for the lifting equipment (such as overhead crane, hoist, etc.). Through the lifting ring 4, the lifting equipment can easily attach wire ropes or hooks to realize the lifting and movement of the entire anti-deformation constraint fixture used for milling the inner cavity of the workpiece.

[0066] Example 2

[0067] Embodiment 2 of the present invention is a further improvement based on Embodiment 1, such as... Figure 2 As shown, the anti-deformation constraint fixture for milling the inner cavity of a workpiece also includes a follow-up clamping assembly 7. The follow-up clamping assembly 7 includes a support frame 71, a follow-up motor 72, a connecting arm 73, a telescopic rod 74, and a clamping plate 75. The support frame 71 is fixedly mounted on the inner cavity clamping plate 3, the follow-up motor 72 is fixedly mounted on the support frame 71, the connecting arm 73 is connected to the rotating shaft of the follow-up motor 72, the telescopic rod 74 is fixedly mounted on the connecting arm 73 and can extend and retract, and the clamping plate 75 is connected to the extended end of the telescopic rod 74 to clamp the inner wall of the workpiece. The follow-up motor 72 can drive the connecting arm 73, the telescopic rod 74, and the clamping plate 75 to rotate below the area to be milled to clamp the inner wall of the workpiece below the milling area.

[0068] The support frame 71 provides a stable mounting position for the follower motor 72, ensuring that the follower motor 72 remains fixed during operation, thereby guaranteeing the stability and reliability of the entire follower clamping assembly 7. The follower motor 72 drives the connecting arm 73, the telescopic rod 74, and the clamping plate 75 to rotate, allowing the clamping plate 75 to move flexibly to different positions, especially to rotate below the area to be milled, to clamp different inner wall positions of the workpiece. The connecting arm 73 is connected to the rotating shaft of the follower motor 72, serving to transmit power and change the direction of movement. The distance between the clamping plate 75 and the inner wall of the workpiece can be adjusted to adapt to workpieces of different shapes and sizes, ensuring that the clamping plate 75 can tightly press against the inner wall of the workpiece, providing sufficient clamping force to prevent deformation of the workpiece during milling. The clamping plate 75 applies clamping force to the inner wall of the workpiece, fixing the workpiece in a suitable position and preventing deformation of the inner wall of the workpiece due to cutting force during milling. In summary, through the coordinated work of various components of the follow-up clamping assembly 7, the inner wall of the workpiece can be dynamically clamped during milling. The follow-up motor 72 can drive the clamping plate 75 to rotate below the area to be milled, and the telescopic rod 74 adjusts the clamping distance according to the actual situation of the inner wall of the workpiece, so that the clamping plate 75 is always tightly attached to the inner wall of the workpiece, providing clamping force to resist the cutting force generated during milling, thereby reducing the deformation of the inner cavity of the workpiece during milling and improving the machining accuracy and dimensional stability of the workpiece.

[0069] In one specific embodiment, the follow-up clamping assembly 7 further includes a follow-up control device, which includes:

[0070] The position acquisition unit is used to acquire the real-time machining position of the milling tool;

[0071] The control unit, connected to the position acquisition unit, is used to calculate the corresponding workpiece inner wall support position based on the real-time processing position and generate a follow-up control signal. The control unit sends the follow-up control signal to the follow-up motor 72 to control the follow-up motor 72 to drive the connecting arm 73, telescopic rod 74 and clamping plate 75 to rotate to the support position, and controls the telescopic rod 74 to extend so that the clamping plate 75 presses the inner wall of the workpiece.

[0072] Specifically, the position acquisition unit can be the CNC system of the milling machine; the control unit can also be the CNC system of the milling machine. By directly utilizing the CNC system built into the machine tool, the follower motor 72 and the telescopic rod 74 can be precisely controlled.

[0073] In one specific implementation, such as Figure 3As shown, the pressing plate 75 includes a pressing plate body 751, a rigid support block 752, and a flexible support block 753. The pressing plate body 751 has an arc that can fit against the inner wall of the workpiece. The rigid support block 752 and the flexible support block 753 are both fixed on the pressing plate body 751, and the support height of the flexible support block 753 is higher than that of the rigid support block 752. A deformation gap 754 is provided between the rigid support block 752 and the flexible support block 753.

[0074] The curved design of the pressure plate body 751 allows it to fully conform to the inner wall of the workpiece, ensuring uniform distribution of clamping force and preventing localized stress concentration that could lead to workpiece deformation or slippage of the pressure plate 751. The rigid support block 752, made of high-rigidity material (such as metal or hard engineering plastic), provides basic support and bears the main load during the clamping process to achieve clamping of the inner wall of the workpiece. The flexible support block 753, made of elastic material (such as rubber, silicone, or polyurethane), has a higher support height than the rigid support block 752, forming a buffer layer for adaptive compensation. When there are minor unevennesses on the workpiece surface (such as burrs or wavy lines), the flexible support block 753 absorbs the error through elastic deformation, maintaining continuous contact between the clamping surface and the workpiece. It also reduces vibration and noise during milling. During the milling process, the flexible material can attenuate vibration energy, reduce machining noise, and improve surface quality. The deformation gap 754 is located between the rigid support block 752 and the flexible support block 753, providing space for the elastic deformation of the flexible support block 753. Moreover, it can prevent the flexible support block 753 from squeezing the rigid support block 752 due to lack of deformation space when under pressure, which could lead to structural damage or abnormal clamping force. The combined design of the rigid support block 752 and the flexible support block 753 allows the clamping plate 751 to withstand large loads (rigid support) and adapt to micro-defects on the workpiece surface (flexible compensation), achieving a clamping effect that combines rigidity and flexibility. The damping effect of the flexible support block 753 can reduce the vibration amplitude during the milling process, thereby extending tool life and improving machining accuracy.

[0075] The technical solution of this embodiment is particularly suitable for milling the internal cavities of thin-walled components. Related technologies using rigid clamping fixtures are difficult to adapt to dynamic changes in cutting forces during machining, and cannot provide effective following support in the tool movement area, leading to problems such as local deformation of the workpiece, vibration and chatter, and surface quality defects. The technical solution of this embodiment aims to solve the above-mentioned technical problems.

[0076] Example 3

[0077] Embodiment 3 of the present invention is a further improvement based on Embodiment 1 or Embodiment 2. The anti-deformation constraint fixture for milling the inner cavity of a workpiece further includes a second constraint component 5, such as... Figure 4As shown, the second constraint component 5 includes: an oil pump, an oil distribution box 51, an oil flow pipe 52, a receiving groove 53, and a constraint bladder 54. The oil distribution box 51 is connected to the oil pump to obtain oil. The oil flow pipe 52 is connected between the oil distribution box 51 and the constraint bladder 54 to deliver oil to the constraint bladder 54 to squeeze the inner wall of the workpiece. The receiving groove 53 is sleeved on the oil flow pipe 52 and wraps around part of the constraint bladder 54 to support the constraint bladder 54.

[0078] The oil pump is the power source for the entire second constraint assembly 5. Under the control of the control system (such as using a PLC or microcontroller), it can generate sufficient pressure to drive the oil flow and provide the energy required for the expansion of the constraint bladder. By adjusting the output pressure and flow rate of the oil pump, the degree and speed of the expansion of the constraint bladder can be precisely controlled, thereby achieving precise adjustment of the extrusion pressure on the inner wall of the workpiece.

[0079] The oil distribution box 51 serves as the connection hub between the oil pump and the oil flow pipe 52, and plays the role of collecting and distributing the oil. It collects the oil output by the oil pump and then distributes it evenly to the constraint bladder 54 through multiple oil flow pipes 52, ensuring that each constraint bladder 54 can obtain enough oil and realize the synchronous expansion of the constraint bladders 54 at different positions.

[0080] The oil flow pipe 52 is connected between the oil distribution box 51 and the restraint bladder 54, and is responsible for transporting oil from the oil distribution box 51 to the restraint bladder 54.

[0081] The receiving groove 53 is fitted onto the oil flow pipe 52 and wraps around part of the constraint bladder 54, providing structural support for the constraint bladder 54. In addition, the receiving groove 53 can also play a positioning and guiding role, ensuring that the constraint bladder 54 expands in the correct direction and position during the expansion process.

[0082] The constraint capsule 54 is the part of the second constraint assembly 5 that directly contacts the inner wall of the workpiece. When the oil enters the constraint capsule 54 through the oil flow pipe 52, the constraint capsule 54 will expand and squeeze the inner wall of the workpiece, thereby enhancing the rigidity of the workpiece, reducing the elastic deformation ("tool deflection") caused by insufficient rigidity under the action of cutting force, and ensuring the machining dimensional accuracy of the workpiece.

[0083] In summary, by combining the oil pump, oil distribution box 51, oil flow pipe 52, receiving groove 53, and constraint bladder 54, the rigidity of the workpiece is enhanced. Through the compression of the inner wall of the workpiece by the constraint bladder 54, the second constraint component 5 effectively enhances the rigidity of the workpiece. During the cutting process, the workpiece can better resist the cutting force, reducing dimensional errors and shape deviations caused by elastic deformation, thereby improving the machining accuracy and surface quality of the workpiece. The design of the oil distribution box and oil flow pipe makes the extrusion pressure more uniform, ensuring that each constraint bladder receives a uniform oil supply, thus applying uniform extrusion pressure to the inner wall of the workpiece. This avoids deformation of the workpiece caused by uneven local stress, further improving machining accuracy.

[0084] As a specific implementation method, such as Figure 5 As shown, the receiving groove 53 includes a receiving groove body 531 and a fixing hole 532 opened on the receiving groove body 531. The oil flow pipe 52 passes through the fixing hole 532 and communicates with the restraint bladder 54. The receiving groove body 531 wraps around part of the restraint bladder 54 to support the restraint bladder 54.

[0085] The receiving tank body 531 is used to receive the positioning constraint bladder 54, provide a support structure and guide the expansion direction; for example, the cross-section of the receiving tank body 531 can be semi-circular; the fixing hole 532 is used to fix the oil flow pipe 52, the oil flow pipe 52 passes through the fixing hole 532, so that the oil flow pipe 52 can be stably installed on the receiving tank 53, thereby ensuring that the oil flow pipe 52 will not be displaced or shaken during the oil transportation process, and ensuring that the oil can be accurately and stably transported from the oil distribution box 51 to the constraint bladder 54.

[0086] In a specific implementation, the second constraint component 5 also includes a solenoid valve, which is disposed on the oil flow pipe 52 to control the flow rate of the oil.

[0087] The solenoid valve controls the opening of the valve core through the action of electromagnetic force, thereby precisely regulating the flow rate of oil through the oil flow pipe. During the workpiece processing, different processing stages (such as roughing and finishing) and different workpiece characteristics (such as wall thickness and material) have different requirements for the internal cavity constraint force. The solenoid valve can quickly and accurately adjust the oil flow rate according to the preset program or real-time feedback signal, thereby changing the constraint force applied to the internal cavity of the workpiece by the second constraint component.

[0088] As a specific implementation method, such as Figure 6As shown, the restraint capsule 54 includes several restraint capsule units 541. Each restraint capsule unit 541 includes a bottom support 542, a partition plate 543, and a telescopic surface 544. The partition plate 543 is embedded on both sides of the bottom support 542 and the two are sealed. The telescopic surface 544 is fixed on the bottom support 542 and the partition plate 543 and is sealed with both the bottom support 542 and the partition plate 543. The bottom support 542 is fixed on the receiving groove 53.

[0089] The bottom support 542 supports the spacer plate 543 and the telescopic surface 544, and also plays a positioning role when the constraint capsule unit 541 is installed on structures such as the receiving groove. The spacer plate 543 is embedded on both sides of the bottom support 542, forming a relatively closed independent space together with the bottom support 542 and the telescopic surface 544. After the oil enters the constraint capsule unit 541, the spacer plate 543 can restrict the expansion direction of the constraint capsule unit 541, causing it to expand mainly in the direction of the telescopic surface 544, thereby more effectively applying extrusion force to the inner wall of the workpiece. The telescopic surface 544 is the direct... When the oil enters the constraint capsule unit 541, the expansion surface 544 will expand and deform under the pressure of the oil, thereby applying a uniform extrusion force to the inner wall of the workpiece, enhancing the rigidity of the workpiece, and reducing workpiece deformation during processing. For example, the expansion surface 544 can be made of silicone rubber or thermoplastic elastomer (TPE). Multiple constraint capsule units 541 work together. Through the cooperation of the bottom support 542, the spacer plate 543 and the expansion surface 544, the oil can be distributed to the constraint capsule unit 541 in a targeted manner to compress and constrain the position of the workpiece that needs to be constrained.

[0090] As a specific implementation method, such as Figure 7 As shown, the restraint bladder unit 541 also includes an elastic reset unit 545, which is connected between the telescopic surface 544 and the bottom support 542. The elastic reset unit 545 provides a pre-tightening force to keep the telescopic surface 544 in a predetermined position when no oil is filled.

[0091] The elastic reset unit 545 provides pre-tightening force through its own elastic deformation characteristics. When no oil is filled into the restraint bladder unit 541, the elastic reset unit 545 is in a natural or pre-compressed state and applies a pulling or pushing force to the telescopic surface 544, pulling or pushing the telescopic surface 544 back to a predetermined position. This predetermined position is the designed initial position, ensuring that the restraint bladder unit 541 is in a stable contracted state when no oil is applied, preparing for subsequent oil filling and expansion. When oil is filled into the restraint bladder unit 541, the pressure of the oil will overcome the pre-tightening force of the elastic reset unit 545, causing the telescopic surface 544 to expand outward. When the oil is discharged, the pre-tightening force of the elastic reset unit 545 causes the telescopic surface 544 to return to the predetermined position. For example, the elastic reset unit 545 can be a spring or elastic rubber component arranged at equal intervals.

[0092] Based on this, such as Figure 7 As shown, the constraint capsule unit 541 also includes a first support plate 546 and a second support plate 547. The first support plate 546 is fixedly disposed on the partition plate 543, and the second support plate 547 is fixedly disposed on the inner wall of the telescopic surface 544. The elastic reset unit 545 is disposed between the first support plate 546 and the second support plate 547.

[0093] The first support plate 546 is fixedly mounted on the partition plate 543, providing a stable fixing point for the elastic reset unit 545. This ensures that one end of the elastic reset unit 545 is fixed, allowing it to accurately apply and transmit force during operation. The second support plate 547 is fixedly mounted on the inner wall of the telescopic surface 544. Its main function is to connect the elastic reset unit 545 and the telescopic surface 544. Through the second support plate 547, the preload generated by the elastic reset unit 545 is accurately transmitted to the telescopic surface 544, enabling it to return to its predetermined position when no oil is injected. Simultaneously, it assists in telescopic movement when oil is injected. The expansion surface 544 expands smoothly. In summary, the elastic reset unit 545 can accurately apply pre-tightening force, thereby precisely controlling the predetermined position of the expansion surface 544 when no oil is filled. During the filling and discharging of oil, the elastic reset unit 545 achieves smooth force transmission with the expansion surface 544 through the first support plate 546 and the second support plate 547. When oil is filled, the expansion surface 544 can expand outward evenly, avoiding local over-expansion or deformation. When oil is discharged, the elastic reset unit 545 can make the expansion surface 544 smoothly retract back to the predetermined position, reducing vibration and impact during the expansion and contraction process, and improving the stability and reliability of the constraint bladder unit 541.

[0094] In a specific implementation, the second constraint component 5 also includes a lifting component, and the oil distribution box 51 is disposed on the lifting component to realize lifting. The lifting component is connected to the oil pump to obtain lifting power.

[0095] The lifting assembly is a component that enables the adjustment of the inner wall constraint height. It can move the oil distribution box 51 to the corresponding position according to the specific conditions of the inner wall at different heights, so that the oil distribution box 51 can drive the oil flow pipe 52, the receiving tank 53 and the constraint bladder 54 to reach the various height points that need to be constrained, thereby meeting the constraint requirements of the inner wall at different heights.

[0096] Example 4

[0097] Embodiment 4 of the present invention is a further improvement on Embodiment 3, wherein a sensor for sensing the deformation of the inner wall of the workpiece is integrated on the telescopic surface 544 of the constraint capsule unit 541.

[0098] The sensor is installed on the telescopic surface 544 and can sense the deformation of the telescopic surface 544 in real time, thereby reflecting the deformation of the inner wall of the workpiece. By converting physical deformation into electrical signals or other measurable signals, the sensor can accurately measure information such as the amplitude, direction, and rate of inner wall deformation. The sensor feeds back the sensed inner wall deformation information to the control system. Based on this feedback information, the control system adjusts the expansion pressure, expansion speed, and other parameters of the constraint capsule unit 541 in real time to achieve precise control of the inner wall deformation. If the sensor detects that the deformation at a certain point on the inner wall exceeds the preset range, the control system promptly adjusts the force of the constraint capsule unit 541 to restore the inner wall to the specified shape and size. During the constraint process, the deformation of the inner wall of the workpiece may change due to various factors, such as material inhomogeneity and thermal stress during processing. The sensor can sense these changes in time and feed the information back to the control system. The control system can quickly adjust the parameters of the constraint capsule unit 541 to achieve real-time dynamic control of the inner wall deformation and ensure that the constraint process is always in the optimal state.

[0099] Specifically, the sensor is a flexible piezoresistive pressure sensor or a flexible capacitive pressure sensor, and the sensor is embedded or attached in an array within the telescopic surface 544.

[0100] Alternatively, the sensor may be an eddy current displacement sensor or a miniature laser displacement sensor, which is embedded in a specific position on the telescopic surface 544 to directly measure the distance to the inner wall of the workpiece.

[0101] The anti-deformation constraint fixture for milling the inner cavity of a workpiece also includes a control system that receives signals from the sensor and adjusts the output of the oil pump in real time based on the signals to compensate for the pressure in the concave area.

[0102] Those skilled in the art should understand that the above embodiments are merely for illustrating the present invention and are not intended to limit the scope of the invention. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present invention.

Claims

1. A deformation-resistant constraint fixture for milling the inner cavity of a workpiece, characterized in that, Includes a positioning stage, a first constraint assembly, an inner cavity clamping plate, and a base platform; The positioning stage is fixedly mounted on the base platform, and the base platform is movably mounted on the machine tool worktable. The first constraint component is mounted on the positioning stage and constrains the workpiece position from the outer periphery of the workpiece. The inner cavity clamping plate is mounted on the positioning stage and abuts against the bottom inner wall of the workpiece to constrain the bottom of the workpiece position from within the workpiece. The first constraint component includes multiple constraint units, which constrain a portion of the workpiece position from the outer periphery of the workpiece. Each constraint unit includes a constraint unit and a constraint plate, with the constraint plate located on the constraint unit and abutting against the workpiece. The first constraint component also includes a buffer member, which is placed on the inner wall of the first constraint component. The buffer member includes an embedding groove and a buffer strip, with the embedding groove formed on the inner wall of the first constraint component and the buffer strip embedded in the embedding groove and abutting against the workpiece. The tooling also includes a second constraint assembly, which includes an oil pump, an oil distribution box, an oil flow pipe, a receiving groove, and a constraint bladder. The oil distribution box is connected to the oil pump to obtain oil. The oil flow pipe is connected between the oil distribution box and the constraint bladder to deliver the oil to the constraint bladder to compress the inner wall of the workpiece. The receiving groove is sleeved on the oil flow pipe and wraps around a portion of the constraint bladder to support it.

2. The anti-deformation constraint fixture for milling the inner cavity of a workpiece according to claim 1, characterized in that, It also includes a height adjustment block, which is placed between the positioning platform and the base platform to adjust the height of the positioning platform and to provide a space for accommodation between the positioning platform and the base platform.

3. The anti-deformation constraint fixture for milling the inner cavity of a workpiece according to claim 1, characterized in that, The positioning platform has a first chip outlet hole to allow chips from the workpiece cavity to flow out of the workpiece cavity.

4. The anti-deformation constraint fixture for milling the inner cavity of a workpiece according to claim 1, characterized in that, The inner cavity clamping plate is provided with a second chip outlet hole.

5. The anti-deformation constraint fixture for milling the inner cavity of a workpiece according to claim 1, characterized in that, The constraint unit further includes a connecting handle disposed on the constraint unit for connection with adjacent constraint units.

6. The anti-deformation constraint fixture for milling the inner cavity of a workpiece according to claim 1, characterized in that, The positioning platform is also fixedly equipped with a lifting ring to suspend the anti-deformation constraint fixture used for milling the inner cavity of the workpiece.

Images