A negative Poisson's ratio vibration absorption base for milling thin-walled parts and a milling device

Abstract

The present invention relates to a negative Poisson's ratio vibration-absorbing base for milling thin-walled parts and a milling device, belonging to the technical field of machining. It solves the defects existing in the current thin-walled part milling device, and includes a bottom plate and a workpiece support plate arranged in parallel. A plurality of vibration damping units are provided between the bottom plate and the workpiece support plate. The vibration damping unit includes a negative Poisson's ratio structure, which is fixed on the first vertical plate. The top end of the first vertical plate is fixed to the workpiece support plate, and the bottom end is fixed to the bottom plate. Bending beams are provided on both sides of a part of the first vertical plate 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 on the bottom plate. Both the bending beam and the negative Poisson's ratio structure are made of shape memory alloy materials. The vibration-absorbing base of the present invention has a simple structure and will not increase the processing cost during use.

Description

Technical Field

[0001] The present invention relates to the technical field of machining equipment, and particularly relates to a negative Poisson's ratio vibration-absorbing base for thin-walled part milling and a milling device. Background Art

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

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

[0004] Patent CN105935795B discloses an adjustable damping vibration reduction and chatter suppression device and method during thin-walled part milling, including: a vibration reduction and chatter suppression device, which includes a sealed cavity, a top plate is installed on the upper plane of the sealed cavity, 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 coils are wound around the outside of the permanent magnets. Using the above device can reduce the vibration during thin-walled part milling. However, the above device has structures such as magnetorheological fluid, permanent magnets, and coils, with a complex structure, high processing and manufacturing costs, and requires power supply to the coils during use, increasing energy consumption and machining costs. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a negative Poisson's ratio vibration-absorbing base for thin-walled part milling and a milling device, which have excellent vibration reduction performance while having a simple structure, being easy to process and manufacture, not consuming additional energy during use, and not increasing the machining cost of milling.

[0006] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a negative Poisson's ratio vibration absorption base for thin-walled part milling, which includes a bottom plate and a workpiece support plate arranged in parallel. A plurality of vibration damping units are provided between the bottom plate and the workpiece support plate. The vibration damping unit includes a negative Poisson's ratio structure, and the negative Poisson's ratio structure is fixed on a first vertical plate. The top end of the first vertical plate is fixed to the workpiece support plate, and the bottom end is fixed to the bottom plate. Bending beams are provided on both sides of a part of the first vertical plate 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 a second vertical plate fixed to the bottom plate. Both the bending beam and the negative Poisson's ratio structure are made of shape memory alloy materials.

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

[0009] Optionally, the bending beam adopts 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 materials;

[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 materials.

[0012] Optionally, the negative Poisson's ratio vibration absorption base for thin-walled part milling formed by 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 inside the workpiece support plate, and damping particles are provided inside the hollow channels.

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

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

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

[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 absorption 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-damping units between the workpiece support plate and the bottom plate. The vibration-damping 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 support plate is subjected to a downward vibration excitation, the bending beam can immediately respond and produce a negative stiffness effect, that is, when the downward displacement increases, the resistance to deformation force decreases non-linearly, quickly absorbing vibration energy. At the same time, when the negative Poisson's ratio structure is compressed, it outputs a positive stiffness restoring force proportional to the displacement. The positive and negative stiffnesses are complementary, prompting the entire base to reach a zero stiffness state, strongly reducing vibration transmission, and effectively ensuring the machining accuracy and surface quality of thin-walled parts milling. The entire base is composed of a workpiece support plate, a bottom plate, and a plurality of vibration-damping units therebetween, without the need to set up complex structures such as magnetorheological fluid, permanent magnet, and coil. 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 without using additional energy, without additional energy consumption and processing cost.

[0020] 2. The vibration-absorbing base of the present invention is made by 3D metal printing technology, and the product has high customization characteristics. For the milling conditions of thin-walled parts with different materials, shapes, and sizes, it can be conveniently adjusted by adjusting the scale of the vibration-damping unit, the parameters of the bending beam and the negative Poisson's ratio structure to achieve a perfect fit between the vibration-absorbing base and 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, greatly broadening the application range. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

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

[0023] Figure 2 is the front view of the overall structure of Embodiment 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 OF THE EMBODIMENTS

[0025] For the convenience of description, if the words "upper" and "lower" appear in the present invention, they only represent the same upper and lower directions as those of the drawings themselves, and do not limit the structure. It is 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 operated in a specific orientation, so it cannot be understood as a limitation to the present invention.

[0026] Example 1

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

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

[0029] The vibration-damping 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 bending beam 4, the first vertical plate 5, the second vertical plate 6, as well as the bottom plate 2 and the workpiece support plate 1 are all made of shape memory alloy. During processing, they are integrally formed by metal 3D printing technology.

[0031] Using metal 3D printing technology has high processing accuracy, is convenient for the forming of complex structures, and at the same time, the products of metal 3D printing have highly customized characteristics. For the milling working conditions of thin-walled parts with different materials, shapes and sizes, it is possible to conveniently adjust the scale of the vibration-damping unit, the parameters of the bending beam 4 and the negative Poisson's ratio structure 3 to achieve the 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, greatly expanding the application range.

[0032] Preferably, the negative Poisson's ratio structure 3, the bending beam 4, the first vertical plate 5, the second vertical plate 6, as well as the bottom plate 2 and the workpiece support plate 1 are all made of nickel-titanium memory alloy material. This not only expands the application boundary of nickel-titanium memory alloy in the field of vibration absorption, but also fully excavates the potential performance of the material through 3D printing technology, injecting new vitality into the development of the field of materials science and engineering, and promoting 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 and perpendicularly fixedly connected to the workpiece support plate 1, and the bottom end is integrally and perpendicularly fixedly connected 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 points between two opposite branches. The negative Poisson's ratio structure 3 divides the first vertical plate 5 into two parts, namely the upper part and the lower part above the negative Poisson's ratio structure 3. 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 can be understood that the negative Poisson's ratio structure 3 can also adopt other shaped negative Poisson's ratio structures, which can be set by those skilled in the art according to actual needs and will not be described in detail here.

[0036] On both sides of the first vertical plate part above the negative Poisson's ratio structure 3, there are bending beams 4. In this embodiment, the bending beams adopt S-shaped beams. One end of the bending 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 bending beam 4 can also adopt a wavy 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 bending beam 4 and the first vertical plate 5 and the bottom plate 2 is greater than the distance between the connection position between the bending beam 4 and the second vertical plate 6 and the bottom plate 2.

[0039] For the vibration absorption 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 a downward vibration excitation, the bending beam 4 immediately responds. By virtue of its shape and material properties, it produces a negative stiffness effect contrary to the conventional one, that is, when the downward displacement increases, the resistance to deformation force decreases non-linearly, and the vibration energy is quickly absorbed. At the same time, relying on its own microscopic structure, the negative Poisson's ratio structure 3 has an orderly deformation of the internal tissue of the material under pressure and outputs a positive stiffness restoring force proportional to the displacement. The positive and negative stiffnesses complement each other, enabling the entire vibration absorption base to reach a quasi-zero stiffness state, strongly reducing the vibration transmission, and effectively ensuring the machining accuracy and surface quality of the thin-walled parts during milling.

[0040] In order to further dissipate the vibration energy and achieve vibration reduction, a plurality of hollow channels 7 are provided 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 length direction of the negative Poisson's ratio structure and the bending beam. A plurality of damping particles are provided inside the hollow channel. In this embodiment, the damping particles adopt steel balls 8.

[0041] When adopting the metal 3D printing process, both ends of the hollow channel 7 can only be arranged in an open manner. In order to prevent the damping particles from flowing out of the hollow channel 7, blocking members are arranged at both ends of the hollow channel 7 to block both ends of the hollow channel.

[0042] In this embodiment, the blocking members adopt blocking bolts. Thread tapping is performed at both ends of the hollow channel 7, and the blocking bolts are threadedly connected to both ends of the hollow channel to achieve the blocking of the hollow channel.

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

[0044] The length of the bottom plate 2 is greater than the length of the workpiece support plate 1. Clamp fixing holes 9 are arranged on both sides of the projection area of the workpiece support plate 1 on the bottom plate 2. Preferably, two clamp fixing holes 9 are provided on each side. The bottom plate 2 can be installed with clamps through the clamp fixing holes 9, and the clamps are used to clamp the thin-walled part from both sides, playing a role in positioning the thin-walled part.

[0045] Adopting the negative Poisson's ratio vibration absorption base for milling thin-walled parts in this embodiment, combining the negative Poisson's ratio structure 3 with the bending beam 4, and utilizing their unique positive and negative stiffness characteristics, the vibration energy can be accurately offset during the milling process of thin-walled parts. When the milling cutter 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 the 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 processed surface of the thin-walled part can be effectively reduced, the machining accuracy can be significantly improved, and the processing requirements of high-precision thin-walled parts can be met.

[0046] Moreover, the vibration absorption base of this embodiment is integrally formed by the metal 3D printing process. Compared with the current vibration absorption base that requires complex structures such as magnetorheological fluid, permanent magnet, and coil, the structure is simpler, the processing and manufacturing are more convenient, it is made of nickel-titanium memory alloy, has a light weight, and the workpiece support plate 1 adopts a flat plate, which is more convenient to cooperate with the thin-walled part. The bottom plate 2 also adopts a flat plate, which is convenient to be directly fixed on the milling machine and has a light weight, and will not have a negative impact on the dynamic characteristics of the thin-walled part processing system, neither affecting the original processing operation of the thin-walled part nor maximizing the vibration reduction effect and reducing the interference to the overall performance of the processing system.

[0047] The vibration absorption base of this embodiment realizes the vibration reduction function by using its own structural and material characteristics during use, without the need to additionally use electric energy or other energy sources, reducing energy consumption and not increasing the milling processing cost additionally.

[0048] Embodiment 2

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

[0050] The foregoing are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A negative Poisson's ratio vibration absorption base for milling thin-walled parts, characterized in that It includes a bottom plate and a workpiece support plate arranged in parallel. There are multiple vibration damping units between the bottom 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 on the first vertical plate. The top end of the first vertical plate is fixed to the workpiece support plate, and the bottom end is fixed to the bottom plate. Bending beams are provided on both sides of the part of the first vertical plate 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 on the bottom plate. Both the bending beam and the negative Poisson's ratio structure are made of shape memory alloy materials; The distance between the connection position of the bending beam and the first vertical plate and the bottom plate is greater than the distance between the connection position of the bending beam and the second vertical plate and the bottom plate; The bending beam adopts an S-shaped beam.

2. The negative Poisson's ratio vibration absorption base for milling thin-walled parts according to 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 materials.

3. The negative Poisson's ratio vibration absorption base for milling thin-walled parts according to claim 2, characterized in that, The shape memory alloy material adopts a nickel-titanium memory alloy material. 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 materials.

4. The negative Poisson's ratio vibration absorption base for milling thin-walled parts according to claim 2, characterized in that, The negative Poisson's ratio vibration absorption base for thin-walled part milling 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.

5. The negative Poisson's ratio vibration absorption base for milling thin-walled parts according to claim 1, characterized in that, A plurality of hollow channels are arranged inside the workpiece support plate, and damping particles are arranged inside the hollow channels.

6. The negative Poisson's ratio vibration absorption base for milling thin-walled parts according to claim 5, characterized in that, The damping particles adopt steel balls.

7. The negative Poisson's ratio vibration absorption base for milling thin-walled parts according to claim 1, characterized in that, The negative Poisson's ratio structure adopts a four-pointed star structure.

8. The negative Poisson's ratio vibration absorption base for milling thin-walled parts according to claim 1, characterized in that, The bottom plate is provided with fixture fixing holes, and the bottom plate can be fixed to the workpiece fixture through the fixture fixing holes.

9. A thin-walled part milling device, characterized in that, There is provided a negative Poisson's ratio vibration absorption base for thin-walled part milling according to any one of claims 1-8.

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