A new type of magnetic spring quasi-zero stiffness damping vibration reduction tool

Abstract

The present application belongs to the field of metal cutting, and aims to provide a new type of magnetic spring quasi-zero stiffness damping vibration reduction tool, which has the characteristics of good vibration reduction effect and wide vibration reduction frequency range. The technical scheme is a new type of magnetic spring quasi-zero stiffness damping vibration reduction tool, which comprises a tool bar; characterized in that: it further comprises an inner magnetic ring unit, an outer magnetic ring unit, a torsional spring mechanism and an eccentric block; the inner magnetic ring unit is rotatably positioned between the tool bar and the outer magnetic ring unit, the torsional spring mechanism connects the inner magnetic ring unit and the outer magnetic ring unit, and the eccentric block is arranged in the inner magnetic ring unit.

Description

Technical Field

[0001] This invention belongs to the field of metal cutting and machining, and in particular relates to a novel magnetic spring quasi-zero stiffness damping vibration reduction tool. Background Technology

[0002] With the development of mechanical manufacturing technology, deep-hole parts are widely used in military and civilian fields. Boring is a relatively effective method for deep-hole machining, but an excessively large length-to-diameter ratio of the boring bar can lead to a decrease in overall stiffness, exacerbate cutting chatter, and seriously affect cutting stability and machining accuracy. Therefore, the development of damping and vibration-reducing tools has always been a research hotspot in the field of deep-hole machining.

[0003] Traditional damping vibration reduction tools utilize rubber damping to dissipate energy and reduce tool vibration. However, the damping energy dissipation mechanism of this method is unclear, making it difficult to guide rubber damping parameters and structural design, and hindering further improvement in damping vibration reduction effects. In recent years, vibration reduction methods based on dynamic vibration absorbers have been widely researched and applied in various engineering fields. Developing vibration-damping boring bars with dynamic vibration absorbers is an emerging research direction for reducing cutting chatter. Currently, research on damping vibration reduction tools mainly focuses on the structural design of dynamic vibration absorbers.

[0004] Damped cutting tools with dynamic vibration absorbers primarily utilize the principle of linear vibration absorption to reduce tool vibration. By setting appropriate absorber parameters, the cutting stability range of the damped boring bar can be significantly improved. Even with increased cutting parameters, the tool can still maintain cutting stability. This technology is nearing perfection and has been used to develop damped boring bars with better stability.

[0005] However, due to the limited internal space of the boring bar, the vibration absorption mass of the dynamic vibration absorber is small, the vibration amplitude is low, and the vibration reduction effect is not obvious. In addition, the damping vibration reduction tool uses the linear vibration absorption principle to realize the tool vibration reduction, which results in a narrow vibration reduction frequency range of the dynamic vibration absorber, which is not conducive to the tool working under complex working conditions. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings in the above-mentioned background technology and provide a novel magnetic spring quasi-zero stiffness damping vibration reduction tool, which should have the characteristics of good vibration reduction effect and wide vibration reduction frequency range.

[0007] The technical solution of this invention is:

[0008] A novel magnetic spring quasi-zero stiffness damping vibration reduction tool includes a tool holder; characterized in that it further includes an inner magnetic ring unit, an outer magnetic ring unit, a torsion spring mechanism, and an eccentric block; the inner magnetic ring unit is rotatably positioned between the tool holder and the outer magnetic ring unit, the torsion spring mechanism connects the inner magnetic ring unit and the outer magnetic ring unit, and the eccentric block is disposed in the inner magnetic ring unit.

[0009] The inner magnetic ring unit includes an inner housing rotatably positioned on the tool holder and a plurality of inner magnets disposed within the inner housing; the outer magnetic ring unit includes an outer housing and a plurality of outer magnets disposed within the outer housing; the inner and outer magnets are uniformly arranged around the tool holder; the magnetic field lines of the inner and outer magnets are both radial.

[0010] In the inner magnetic ring unit, the magnetic field lines of the inner magnets are in the same direction; in the outer magnetic ring unit, the magnetic field lines of two adjacent outer magnets are in opposite directions; the number of outer magnets is twice the number of inner magnets.

[0011] The eccentric block is positioned between two adjacent inner magnets.

[0012] The torsion spring mechanism includes several springs evenly arranged around the tool holder; the two ends of the springs are fixed to the inner magnetic ring unit and the outer magnetic ring unit, respectively.

[0013] The length direction of the spring maintains a certain angle with the radial direction, and the spring is rotationally symmetrical about the tool holder.

[0014] The inner housing is fixed to the sleeve, and the sleeve is rotatably positioned on the tool holder via bearings.

[0015] The inner shell is fixed in the middle of the sleeve, and the two ends of the sleeve are rotatably positioned on the tool holder by bearings.

[0016] A connecting frame is fixed to the outer shell, and a connecting ring is fixed to the sleeve; the two ends of the spring are respectively fixed to the connecting frame and the connecting ring.

[0017] The beneficial effects of this invention are:

[0018] This invention can adjust the vibration absorption frequency by changing the torsional stiffness, and can also broaden the vibration absorption frequency band by utilizing nonlinear torsional stiffness and damping to ensure efficient and stable cutting. The nonlinear torsional stiffness can be adjusted by changing the structural parameters of the torsional spring mechanism to achieve better vibration absorption. The vibration absorption capacity and vibration absorption frequency range can be adjusted by changing the position and number of magnets, the spring connection position, and the mass of the eccentric block. During cutting, the eccentric block twists, which increases the vibration range and improves the vibration absorption effect compared to linear vibration. Moreover, the overall structure is simple, compact, safe, and reliable. Attached Figure Description

[0019] Figure 1 This is one of the three-dimensional structural schematic diagrams of the present invention.

[0020] Figure 2 This is the second three-dimensional structural schematic diagram of the present invention.

[0021] Figure 3 This is a schematic diagram of the main structure of the present invention.

[0022] Figure 4 This is one of the cross-sectional structural schematic diagrams of the present invention.

[0023] Figure 5 This is the second cross-sectional structural schematic diagram of the present invention.

[0024] Figure 6 This is a three-dimensional structural diagram of the inner magnetic ring unit and the outer magnetic ring unit of the present invention.

[0025] Figure 7 This is a front view structural diagram of the inner magnetic ring unit and the outer magnetic ring unit of the present invention.

[0026] Figure 8 This is a three-dimensional structural schematic diagram of the torsion spring mechanism of the present invention.

[0027] Figure 9 This is a schematic diagram showing the connection relationship between the inner magnetic ring unit and the tool holder of the present invention.

[0028] Figure label:

[0029] 1. Tool holder, 2. Inner magnetic ring unit, 2-1. Inner housing, 2-2. Inner magnet, 2-3. Inner magnetic groove, 3. Outer magnetic ring unit, 3-1. Outer housing, 3-2. Outer magnet, 3-3. Eccentric block, 4. Spring, 5. Sleeve, 6. Bearing, 7. Connecting frame, 8. Connecting ring, 9. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the 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 and not intended to limit the invention.

[0031] like Figure 1 As shown, a novel magnetic spring quasi-zero stiffness damping vibration reduction tool includes a tool holder 1, an inner magnetic ring unit 2, an outer magnetic ring unit 3, a torsion spring mechanism, and an eccentric block 4.

[0032] The tool holder, inner magnetic ring unit, and outer magnetic ring unit are arranged coaxially from the inside out. Both the inner and outer magnetic ring units are annular structures. The tool holder axially passes through the outer magnetic ring unit, and the inner magnetic ring unit is rotatably positioned between the tool holder and the outer magnetic ring unit. During tool operation, the positions of the tool holder and the outer magnetic ring unit are fixed, while the inner magnetic ring unit rotates around the axis of the tool holder, with torsional stiffness provided by the outer magnetic ring unit.

[0033] The inner magnetic ring unit includes an inner housing 2-1 and a plurality of inner magnets 2-2. The inner housing is rotatably positioned on the tool holder, and the plurality of inner magnets are disposed within the inner housing and evenly arranged around the tool holder. The outer magnetic ring unit includes an outer shell 3-1 and a plurality of outer magnets 3-2. The outer shell surrounds the inner housing, and the plurality of outer magnets are disposed within the outer shell and evenly arranged around the tool holder.

[0034] The number of outer magnets is twice the number of inner magnets. For example... Figure 7 As shown, there are 4 inner magnets and 8 outer magnets. The inner shell has 8 circumferentially arranged inner magnetic slots 2-3, of which 4 slots contain inner magnets, with the slots containing inner magnets and those not containing inner magnets arranged alternately. The outer shell has 8 circumferentially arranged outer magnetic slots 3-3, and all outer magnetic slots contain outer magnets.

[0035] The magnetic field lines of both the outer and inner magnets are radial. In the inner magnetic ring unit, the magnetic field lines of the inner magnets are in the same direction. In the outer magnetic ring unit, the magnetic field lines of adjacent outer magnets are in opposite directions.

[0036] like Figure 7 As shown, in the inner magnetic ring unit, the magnetic field lines of the inner magnets are all radially converging (from the periphery to the center). In the outer magnetic ring unit, the magnetic field lines of two adjacent outer magnets are in opposite directions, namely radially converging (from the periphery to the center) and radially diverging (from the center to the periphery), respectively. Figure 7 As shown, in the natural state, the magnetic field lines of the inner and outer magnets arranged in the same radial direction are in the same direction.

[0037] like Figure 9 As shown, a sleeve 6 is provided on the outside of the tool holder. The two ends of the sleeve are rotatably positioned on the tool holder by bearings 7. The inner magnetic ring unit is arranged between the bearings on both sides, and the inner shell is fixed in the middle of the sleeve.

[0038] The torsion spring mechanism and the eccentric block are used for vibration absorption. The torsion spring mechanism is located between the inner magnetic ring unit and the outer magnetic ring unit, and the eccentric block is located in the inner magnetic ring unit.

[0039] The eccentric block is installed in one of the inner magnetic slots and is located between two adjacent inner magnets. The vibration absorption effect can be optimized by adjusting the mass of the eccentric block.

[0040] The torsion spring mechanism includes springs 5, which are evenly arranged around the cutter bar. The two ends of each spring are fixed to the inner magnetic ring unit and the outer magnetic ring unit, respectively. A connecting frame 8 is fixed to the outer casing, and a connecting ring 9 is fixed to the sleeve. The two ends of the springs are fixed to the connecting frame and the connecting ring, respectively, by bolts and self-locking nuts. The springs are rotationally symmetrical about the cutter bar, and the length direction of the springs maintains a certain angle with the radial direction of the cutter bar. When the inner and outer magnetic ring units twist relative to each other, the springs provide torsional negative stiffness to the inner magnetic ring unit. Simultaneously, the torsional stiffness of the springs can be adjusted by changing the positions of the connection points at both ends. To ensure that the springs can rotate flexibly during torsion, a certain gap needs to be maintained on both sides of the springs.

[0041] Working principle of this invention:

[0042] The invention also includes a boring tool housing (omitted in the figure). The tool holder, inner magnetic ring unit, outer magnetic ring unit, and torsion spring mechanism are all located in the boring tool housing. The tool holder and the boring tool housing are fixed to the machine tool. When the tool cuts metal, the tool holder vibrates radially (up and down) under the action of cutting force. The eccentric block vibrates torsionally due to inertia, and drives the inner magnetic ring unit to rotate simultaneously. Due to the torsion of the inner magnetic ring unit, the spring is deformed, providing torsional negative stiffness for the inner magnetic ring unit, while the outer magnetic ring unit provides torsional positive stiffness to ensure the return of the inner magnetic ring unit to its original position. The vibration absorption capacity and vibration absorption working range can be adjusted by adjusting the connection position of the spring, changing the mass of the eccentric block, and the number of inner and outer magnets.

[0043] Finally, it should be noted that the above examples are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of this invention should be considered within the scope of protection of this invention.

Claims

1. A novel magnetic spring-driven quasi-zero stiffness damping vibration reduction tool, comprising a tool holder (1); characterized in that: It also includes an inner magnetic ring unit (2), an outer magnetic ring unit (3), a torsion spring mechanism, and an eccentric block (4); the inner magnetic ring unit is rotatably positioned between the tool bar and the outer magnetic ring unit, the torsion spring mechanism connects the inner magnetic ring unit and the outer magnetic ring unit, and the eccentric block is set in the inner magnetic ring unit; The inner magnetic ring unit includes an inner housing (2-1) rotatably positioned on the tool holder and a plurality of inner magnets (2-2) disposed within the inner housing; the outer magnetic ring unit includes an outer housing (3-1) and a plurality of outer magnets (3-2) disposed within the outer housing; the inner and outer magnets are uniformly arranged around the tool holder; the magnetic field lines of the inner and outer magnets are both radial. In the inner magnetic ring unit, the magnetic field lines of the inner magnets are in the same direction; in the outer magnetic ring unit, the magnetic field lines of two adjacent outer magnets are in opposite directions; the number of outer magnets is twice the number of inner magnets. The eccentric block is positioned between two adjacent inner magnets; The torsion spring mechanism includes a plurality of springs (5) evenly arranged around the tool bar; the two ends of the springs are respectively fixed to the inner magnetic ring unit and the outer magnetic ring unit; The length direction of the spring maintains an angle with the radial direction, and the spring is rotationally symmetrical about the tool holder; The inner shell is fixed on the sleeve (6), and the sleeve is rotatably positioned on the tool holder by the bearing (7).

2. The novel magnetic spring quasi-zero stiffness damping vibration reduction tool according to claim 1, characterized in that: The inner shell is fixed in the middle of the sleeve, and the two ends of the sleeve are rotatably positioned on the tool holder by bearings.

3. The novel magnetic spring quasi-zero stiffness damping vibration reduction tool according to claim 2, characterized in that: A connecting frame (8) is fixed on the outer shell, and a connecting ring (9) is fixed on the sleeve; the two ends of the spring are respectively fixed to the connecting frame and the connecting ring.

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