Negative Poisson's ratio vibration absorption base for thin-wall part milling and milling device

Abstract

The invention relates to a negative Poisson's ratio vibration absorption base for thin-walled workpiece milling and a milling device, belongs to the technical field of machining, and solves the defects of a current thin-walled workpiece milling device, the negative Poisson's ratio vibration absorption base comprises a bottom plate and a workpiece supporting plate which are arranged in parallel, a plurality of vibration reduction units are arranged between the bottom plate and the workpiece supporting plate, and each vibration reduction unit comprises a negative Poisson's ratio structure. The negative Poisson's ratio structure is fixed to the first vertical plate, the top end of the first vertical plate is fixed to the workpiece supporting plate, the bottom end of the first vertical plate is fixed to the bottom plate, bent beams are arranged on the two sides of the part, above the negative Poisson's ratio structure, of the first vertical plate, one end of each bent beam is connected with the first vertical plate, and the other end of each bent beam is connected with the second vertical plate fixed to the bottom plate. The bending beam and the negative Poisson's ratio structure are both made of shape memory alloy materials, the vibration absorption base is simple in structure, and the machining cost cannot be increased when the vibration absorption base is used.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing equipment, and in particular to a negative Poisson's ratio vibration absorbing base and a milling device for milling thin-walled parts. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In the field of mechanical processing, thin-walled parts are extremely sensitive to vibration during milling due to their inherent characteristics such as thin walls, light weight, and relatively low rigidity. The vibration generated during the milling process will cause a series of serious problems, greatly affecting the quality of the processed surface, causing a significant increase in surface roughness and obvious vibration marks. In severe cases, it may even cause deformation or damage to thin-walled parts, resulting in processing accuracy that cannot meet requirements. At the same time, vibration will accelerate tool wear and shorten the tool life. Frequent tool replacement not only increases tool costs, but also reduces processing efficiency due to downtime for tool change, thereby increasing overall processing costs.

[0004] Patent CN105935795B discloses an adjustable damping vibration reduction and tremor suppression device and a vibration reduction method in the milling process of thin-walled parts, including: a vibration reduction and tremor suppression device, the vibration reduction and tremor suppression device includes a sealed cavity, a top plate is installed on the sealed cavity plane, the outer layer of the sealed cavity is a constraint layer, a damping layer is installed inside the constraint layer, a damping layer substrate is installed inside the damping layer, a magnetorheological fluid is installed inside the damping layer substrate, 6 permanent magnets are installed in the magnetorheological fluid, and a coil is wound around the outside of the permanent magnet. The above device can reduce the vibration in the milling process of thin-walled parts, but the above device has structures such as magnetorheological fluid, permanent magnets, and coils, and has a complex structure and a high processing and manufacturing cost. In addition, the coil needs to be energized when used, which increases energy consumption and increases processing costs. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a negative Poisson's ratio vibration absorbing base and a milling device for milling thin-walled parts. While ensuring that the vibration absorbing base has excellent vibration reduction performance, the structure is simple and easy to process and manufacture. It does not consume extra energy during use and does not increase the processing cost of milling.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In the first aspect, an embodiment of the present invention provides a negative Poisson's ratio vibration absorbing base for milling thin-walled parts, including a base plate and a workpiece support plate arranged in parallel, a plurality of vibration damping units are arranged between the base plate and the workpiece support plate, the vibration damping unit includes a negative Poisson's ratio structure, the negative Poisson's ratio structure is fixed to a first vertical plate, the first vertical plate is fixed at the top end to the workpiece support plate, and the bottom end to the base plate, bending beams are arranged on both sides of the first vertical plate portion above the negative Poisson's ratio structure, one end of the bending beam is connected to the first vertical plate, and the other end is connected to the second vertical plate fixed to the base plate, and the bending beam and the negative Poisson's ratio structure are both made of shape memory alloy material.

[0008] Optionally, the distance between the connection position of the curved beam and the first vertical plate and the bottom plate is greater than the distance between the connection position of the curved beam and the second vertical plate and the bottom plate.

[0009] Optionally, the curved beam is an S-shaped beam.

[0010] Optionally, the bottom plate, the workpiece support plate, the first vertical plate and the second vertical plate are also made of shape memory alloy material;

[0011] Furthermore, the bottom plate, the workpiece support plate, the negative Poisson's ratio structure, the bending beam, the first vertical plate and the second vertical plate are made of nickel-titanium memory alloy material.

[0012] Optionally, the negative Poisson's ratio vibration absorbing base for milling thin-walled parts, which is composed of the bottom plate, the workpiece support plate, the negative Poisson's ratio structure, the bending beam, the first vertical plate and the second vertical plate, is integrally formed by metal 3D printing.

[0013] Optionally, a plurality of hollow channels are provided in the workpiece support plate, and damping particles are provided in the hollow channels.

[0014] Optionally, the damping particles are steel balls.

[0015] Optionally, the negative Poisson's ratio structure adopts a four-pointed star structure.

[0016] Optionally, the base plate is provided with a fixture fixing hole, and the base plate can be fixed to the workpiece fixture through the fixture fixing hole.

[0017] In a second aspect, an embodiment of the present invention provides a thin-walled part milling device, which is provided with the negative Poisson's ratio vibration absorbing base for thin-walled part milling described in the first aspect.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. The vibration absorbing base of the present invention is provided with a plurality of vibration reduction units between the workpiece supporting plate and the bottom plate, and the vibration reduction units are composed of a negative Poisson's ratio structure and a bending beam, both of which are made of shape memory alloy. When the workpiece supporting plate is subjected to downward pressure vibration excitation, the bending beam can respond immediately to produce a negative stiffness effect, that is, when the downward pressure displacement increases, the resistance to deformation force is nonlinearly reduced, and the vibration energy is quickly absorbed. At the same time, when the negative Poisson's ratio structure is under pressure, a positive stiffness restoring force proportional to the displacement is output, and the positive and negative stiffness complement each other, so as to enable the entire base to reach a zero stiffness state, strongly reduce vibration transmission, and effectively ensure the processing accuracy and surface quality of thin-walled parts milling. The entire base is composed of a workpiece supporting plate, a bottom plate and a plurality of vibration reduction units therebetween. There is no need to set up complex structures such as magnetorheological fluid, permanent magnets and coils. The structure is simple and the processing and manufacturing cost is low. Vibration absorption can be achieved by utilizing the structural performance of the base itself, and no additional energy is needed, which will not increase energy consumption and processing cost.

[0020] 2. The vibration absorbing base of the present invention is made of 3D metal printing technology, and the product has a high degree of customization. For the milling conditions of thin-walled parts of different materials, shapes and sizes, the vibration absorbing base can be easily adjusted by adjusting the parameters of the vibration reduction unit scale, bending beam and negative Poisson's ratio structure to achieve perfect adaptation of the vibration absorbing base to the specific processing task. Whether it is complex thin-walled parts in the aerospace field or small thin-walled structural parts in precision instruments, the most suitable vibration absorbing base can be customized, which greatly broadens the scope of application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] Figure 1 It is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0023] Figure 2 This is a front view of the overall structure of Example 1 of the present invention;

[0024] Among them, 1. workpiece support plate, 2. bottom plate, 3. negative Poisson's ratio structure, 4. bending beam, 5. first vertical plate, 6. second vertical plate, 7. hollow channel, 8. steel ball, 9. fixture fixing hole. DETAILED DESCRIPTION

[0025] For the convenience of description, if the words "upper" and "lower" appear in the present invention, they only indicate that they are consistent with the upper and lower directions of the drawings themselves, and do not limit the structure. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0026] Example 1

[0027] This embodiment provides a negative Poisson's ratio vibration absorbing base for milling thin-walled parts, such as Figure 1-Figure 2 As shown, it includes a workpiece support plate 1 and a base plate 2 arranged in parallel, the workpiece support plate 1 is located above the base plate 2, the workpiece support plate 1 is used to support the thin-walled workpiece to be processed, and the base plate 2 is used to be fixed on the milling machine tool, and a plurality of vibration reduction units are arranged between the workpiece support plate 1 and the base plate 2, and the vibration reduction units are used to dissipate vibration energy to achieve vibration reduction.

[0028] In this embodiment, the workpiece support plate 1 and the base plate 2 are both rectangular plates. In other embodiments, the workpiece support plate 1 and the base plate 2 may also be square plates or circular plates or other types of plates. Those skilled in the art may select according to actual needs.

[0029] The vibration reduction unit includes a negative Poisson's ratio structure 3 , a bending beam 4 , a first vertical plate 5 and a second vertical plate 6 .

[0030] The negative Poisson's ratio structure 3, the curved beam 4, the first vertical plate 5, the second vertical plate 6, the bottom plate 2 and the workpiece support plate 1 are all made of shape memory alloy and are integrally formed by metal 3D printing technology during processing.

[0031] The metal 3D printing process has high processing accuracy and is convenient for the molding of complex structures. At the same time, metal 3D printed products have a high degree of customization. For the milling conditions of thin-walled parts of different materials, shapes and sizes, the vibration-absorbing base can be easily adjusted by adjusting the parameters of the vibration-absorbing unit scale, the bending beam 4 and the negative Poisson's ratio structure 3 to achieve a perfect match between the vibration-absorbing base and the specific processing task. Whether it is a complex thin-walled component in the aerospace field or a small thin-walled structural component in a precision instrument, the most suitable vibration-absorbing base can be customized, which greatly broadens the scope of application.

[0032] Preferably, the negative Poisson's ratio structure 3, the bending beam 4, the first vertical plate 5, the second vertical plate 6, the base plate 2, and the workpiece support plate 1 are all made of nickel-titanium memory alloy material, which not only expands the application boundary of nickel-titanium memory alloy in the field of vibration absorption, but also fully explores the potential performance of the material through 3D printing technology, injects new vitality into the development of materials science and engineering, and enables more high-performance and functional materials to play a key role in industrial manufacturing.

[0033] The top end of the first vertical plate 5 is integrally connected vertically and fixedly to the workpiece support plate 1 , and the bottom end is integrally connected vertically and fixedly to the bottom plate 2 . The negative Poisson's ratio structure is integrally arranged on the first vertical plate.

[0034] In this embodiment, the negative Poisson's ratio structure 3 adopts a four-pointed star structure with four branches. The first vertical plate 5 is connected to the inflection point between two relative branches. The negative Poisson's ratio structure 3 divides the first vertical plate 5 into two parts, namely the part above and the part below the negative Poisson's ratio structure 3, wherein the top of the upper part is integrally connected to the workpiece support plate 1, and the bottom of the lower part is integrally connected to the bottom plate 2.

[0035] It is understandable that the negative Poisson's ratio structure 3 may also adopt negative Poisson's ratio structures of other shapes, which can be configured by those skilled in the art according to actual needs, and will not be described in detail here.

[0036] Curved beams 4 are provided on both sides of the first vertical plate portion above the negative Poisson's ratio structure 3. In this embodiment, the curved beam is an S-shaped beam, one end of the curved beam 4 is integrally connected to the first vertical plate 5, and the other end is integrally connected to the second vertical plate 6. The bottom end of the second vertical plate 6 is vertically and integrally connected to the bottom plate 2.

[0037] In other embodiments, the curved beam 4 may also be a corrugated beam or other types of beams, which can be selected by those skilled in the art according to actual needs and will not be described in detail here.

[0038] Furthermore, the distance between the connection position between the curved beam 4 and the first vertical plate 5 and the bottom plate 2 is greater than the distance between the connection position between the curved beam 4 and the second vertical plate 6 and the bottom plate 2 .

[0039] In the vibration absorbing base of this embodiment, the workpiece support plate 1 is used to support the thin-walled workpiece to be processed. When the workpiece support plate 1 is subjected to downward pressure vibration excitation, the bending beam 4 responds immediately, and produces a negative stiffness effect contrary to the norm by virtue of its shape and material properties, that is, the resistance to deformation force decreases nonlinearly when the downward pressure displacement increases, and the vibration energy is quickly absorbed. At the same time, the negative Poisson's ratio structure 3 relies on its own microstructure, and the internal organization of the material is orderly deformed when under pressure, and a positive stiffness restoring force proportional to the displacement is output. The positive and negative stiffness complement each other, so that the entire vibration absorbing base reaches a quasi-zero stiffness state, strongly reduces vibration transmission, and effectively guarantees the processing accuracy and surface quality of thin-walled parts milling.

[0040] In order to further dissipate the vibration energy and achieve vibration reduction, a plurality of hollow channels 7 are arranged in the workpiece support plate 1. The plurality of hollow channels 7 are parallel and equally spaced. The axis of the hollow channel 7 is parallel to the negative Poisson's ratio structure and the length direction of the bending beam. A plurality of damping particles are arranged inside the hollow channel. In the present embodiment, the damping particles are steel balls 8.

[0041] When the metal 3D printing process is adopted, both ends of the hollow channel 7 can only be opened. In order to prevent the damping particles from flowing out of the hollow channel 7, sealing pieces are provided at both ends of the hollow channel 7 to seal the two ends of the hollow channel.

[0042] In this embodiment, the blocking member is a blocking bolt, which is tapped at both ends of the hollow channel 7, and the blocking bolt is threadedly connected to the two ends of the hollow channel to achieve blocking of the hollow channel.

[0043] When vibration occurs during the processing, the vibration can be transmitted to the damping particles. The damping particles collide with each other, further dissipating the energy generated by the vibration and playing a role in vibration reduction.

[0044] The length of the base plate 2 is greater than that of the workpiece support plate 1, and clamp fixing holes 9 are provided on both sides of the base plate 2 located in the projection area of ​​the workpiece support plate 1. Preferably, two clamp fixing holes 9 are provided on each side, and the base plate 2 can be installed with a clamp through the clamp fixing hole 9. The clamp is used to clamp the thin-walled parts from both sides to play a positioning role for the thin-walled parts.

[0045] The negative Poisson's ratio vibration absorbing base for thin-walled part milling of this embodiment is used to combine the negative Poisson's ratio structure 3 with the bending beam 4, and utilize the unique positive and negative stiffness characteristics of the two to accurately offset the vibration energy during the thin-walled part milling process. When the milling tool generates vibration and transmits it to the base, the negative stiffness of the bending beam 4 quickly absorbs energy, and the positive stiffness of the negative Poisson's ratio structure 3 provides stable support. The two work together to make the base reach a quasi-zero stiffness state. Compared with the base of the traditional thin-walled part milling machine tool, the vibration amplitude can be greatly reduced, the vibration marks on the thin-walled part processing surface can be effectively reduced, and the processing accuracy can be significantly improved to meet the processing requirements of high-precision thin-walled parts.

[0046] Moreover, the vibration absorbing base of this embodiment is integrally formed by metal 3D printing technology. Compared with the current vibration absorbing base which needs to be equipped with complex structures such as magnetorheological fluid, permanent magnet, coil, etc., the structure is simpler and the processing and manufacturing is more convenient. It is made of nickel-titanium memory alloy and is light in weight. The workpiece support plate 1 is a flat plate, which is more convenient to cooperate with thin-walled parts. The bottom plate 2 is also a flat plate, which is convenient to fix directly on the milling machine tool and is light in weight. It will not have a negative impact on the dynamic characteristics of the thin-walled part processing system, and will not affect the original processing operation of the thin-walled parts, but can maximize the vibration reduction effect and reduce interference with the overall performance of the processing system.

[0047] The vibration absorbing base of this embodiment realizes the vibration reduction function by utilizing its own structure and material characteristics when in use, without the need to use additional electrical energy or other energy sources, thus reducing energy consumption and not increasing milling processing costs.

[0048] Example 2

[0049] This embodiment provides a thin-walled part milling device, which is provided with the negative Poisson's ratio vibration absorbing base for thin-walled part milling as described in Example 1. The base plate 2 is fixed on the workbench of the milling device, and clamps are fixed on both sides of the base plate through clamp fixing holes 9. The remaining structure of the milling device can adopt the existing technology and will not be described in detail here.

[0050] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A negative Poisson's ratio vibration absorbing base for milling thin-walled parts, characterized in that: It includes a base plate and a workpiece support plate arranged in parallel, a plurality of vibration reduction units are arranged between the base plate and the workpiece support plate, the vibration reduction unit includes a negative Poisson's ratio structure, the negative Poisson's ratio structure is fixed on the first vertical plate, the first vertical plate is fixed at the top end to the workpiece support plate, and the bottom end is fixed to the base plate, bending beams are arranged on both sides of the first vertical plate part above the negative Poisson's ratio structure, one end of the bending beam is connected to the first vertical plate, and the other end is connected to the second vertical plate fixed to the base plate, and the bending beam and the negative Poisson's ratio structure are both made of shape memory alloy material.

2. A negative Poisson's ratio vibration absorbing base for milling thin-walled parts as claimed in claim 1, characterized in that: The distance between the connection position of the curved beam and the first vertical plate and the bottom plate is greater than the distance between the connection position of the curved beam and the second vertical plate and the bottom plate.

3. A negative Poisson's ratio vibration absorbing base for milling thin-walled parts as claimed in claim 1, characterized in that: The curved beam is an S-shaped beam.

4. A negative Poisson's ratio vibration absorbing base for milling thin-walled parts as claimed in claim 1, characterized in that: The bottom plate, the workpiece support plate, the first vertical plate and the second vertical plate are also made of shape memory alloy material; Furthermore, the bottom plate, the workpiece support plate, the negative Poisson's ratio structure, the bending beam, the first vertical plate and the second vertical plate are made of nickel-titanium memory alloy material.

5. A negative Poisson's ratio vibration absorbing base for milling thin-walled parts as claimed in claim 4, characterized in that: The negative Poisson's ratio vibration absorbing base for milling thin-walled parts, which is composed of the bottom plate, the workpiece support plate, the negative Poisson's ratio structure, the bending beam, the first vertical plate and the second vertical plate, is integrally formed by metal 3D printing.

6. A negative Poisson's ratio vibration absorbing base for milling thin-walled parts as claimed in claim 1, characterized in that: A plurality of hollow channels are arranged in the workpiece support plate, and damping particles are arranged in the hollow channels.

7. A negative Poisson's ratio vibration absorbing base for milling thin-walled parts as claimed in claim 6, characterized in that: The damping particles are steel balls.

8. A negative Poisson's ratio vibration absorbing base for milling thin-walled parts as claimed in claim 1, characterized in that: The negative Poisson's ratio structure adopts a four-pointed star structure.

9. A negative Poisson's ratio vibration absorbing base for milling thin-walled parts as claimed in claim 1, characterized in that: The bottom plate is provided with a fixture fixing hole, and the bottom plate can be fixed to the workpiece fixture through the fixture fixing hole.

10. A thin-walled part milling device, characterized in that: A negative Poisson's ratio vibration absorbing base for milling thin-walled parts as described in any one of claims 1 to 9 is provided.

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