Novel semi-active electromagnetic vibration reduction cutter bar

Abstract

The invention relates to a metal machining cutter bar, in particular to a novel semi-active electromagnetic vibration reduction cutter bar. The invention aims to provide a novel semi-active electromagnetic vibration reduction cutter bar. The cutter bar has the characteristics of good vibration reduction effect and adjustable vibration reduction frequency range. According to the technical scheme, the novel semi-active electromagnetic vibration reduction cutter bar comprises an inner magnetic ring unit, an outer magnetic ring unit and a balancing weight, wherein the inner magnetic ring unit, the outer magnetic ring unit and the balancing weight are rotatably positioned on a center rod; the inner magnetic ring unit and the eccentric balancing weight can deflect relative to the axis of the cutter; the outer magnetic ring unit comprises an electromagnet and is fixed to the center rod, and an external power source supplies power to an electromagnet coil.

Description

Technical Field

[0001] The invention relates to a metal processing tool arbor, in particular to a novel semi-active electromagnetic vibration reduction tool arbor. Background Art

[0002] With the development of manufacturing technology, deep hole processing and deep cavity processing are increasingly widely used in both civilian and military fields. Boring is the main method for deep hole and deep cavity processing, so a boring tool with a large aspect ratio is required; but when the aspect ratio of the boring tool is greater than 4, chatter will occur during cutting, seriously affecting the processing accuracy and stability, and even affecting the safety of workers; therefore, the research and development of vibration-reducing tools has always been a hot topic in the industry.

[0003] At present, the commonly used vibration reduction tools are mainly carbide vibration reduction tools and damping vibration reduction tools with vibration absorbers. Carbide vibration reduction tools use carbide to increase the hardness of the tool and increase its rigidity, so as to reduce the chatter generated by the tool during cutting; this kind of tool has a certain vibration reduction effect, but when the aspect ratio is too large, it will still produce large cutting chatter and reduce the processing accuracy. Another damping vibration reduction tool with a vibration absorber is the mainstream damping vibration reduction tool on the market. A cavity is designed at the front end of the tool, a counterweight is added to the cavity, and a rubber ring is used to provide support; the counterweight vibrates up and down during cutting, and the rubber damping energy consumption is used to reduce the vibration of the tool. By reasonably designing the counterweight mass and adjusting the rubber preload, the vibration of the tool can be greatly reduced and the cutting stability of the tool can be improved. However, this vibration reduction tool uses rubber to provide rigidity and damping, and the relevant parameters are not easy to adjust. The mechanism is unclear, and it is difficult to further improve the vibration absorption effect.

[0004] In recent years, cutting chatter suppression technology based on the principle of dynamic vibration absorption has become the mainstream research direction of vibration-reducing tools. However, when the excitation frequency of the dynamic vibration absorber is within the vibration absorption range, the vibration absorption effect is better and the machining accuracy of the vibration-reducing tool is higher; but when the vibration absorber does not work within the vibration absorption frequency band, the vibration of the vibration-reducing tool is obvious; therefore, this type of vibration-reducing tool is not conducive to working under complex working conditions. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the above-mentioned background technology and to provide a novel semi-active electromagnetic vibration-damping tool arbor, which should have the characteristics of good vibration-damping effect and adjustable vibration-damping frequency range.

[0006] The technical solution provided by the present invention is:

[0007] A novel semi-active electromagnetic vibration-damping tool arbor comprises an inner magnetic ring unit, an outer magnetic ring unit and a counterweight block rotatably positioned on a center rod; the inner magnetic ring unit and the eccentric counterweight block can be deflected relative to the tool axis; the outer magnetic ring unit comprises an electromagnet, the outer magnetic ring unit is fixed to the center rod, and an external power supply supplies power to the electromagnet coil.

[0008] The inner magnetic ring unit includes an inner shell fixed on the counterweight rod and a plurality of inner magnets arranged on the wall of the inner shell; the outer magnetic ring unit includes an outer shell, a plurality of outer magnets installed on the wall of the outer shell and a plurality of coils wound one by one on the plurality of outer magnets; the inner magnet and the outer magnet are both permanent magnets.

[0009] In the inner magnetic ring unit, the direction of the magnetic flux lines of the inner magnet is radial, and the magnetization directions of adjacent inner magnets are opposite; in the outer magnetic ring unit, the direction of the magnetic flux lines of the outer magnet is also radial, and the directions of the magnetic flux lines of two adjacent outer magnets are also opposite, and the direction of the magnetic flux lines generated by the coil is the same as the direction of the magnetic flux lines of the outer magnet around which it is wound; in the non-powered state, the directions of the magnetic flux lines of the inner magnet and the outer magnet at the same radial position are the same.

[0010] The counterweight rod is rotatably positioned on the center rod through a bearing, and the inner magnetic ring is fixedly connected to the counterweight rod; the counterweight block is fixedly connected to the counterweight rod and can rotate around the center rod; the counterweight block is a semi-circular ring structure and is locked on the counterweight rod by screws.

[0011] The inner shell is respectively fixed to the axial ends of the counterweight rod, and the counterweight block is fixed to the middle part of the counterweight rod.

[0012] The central rod is hollow, and a coolant flows through the interior of the central rod.

[0013] The beneficial effects of the present invention are:

[0014] The present invention can change the torsional stiffness by changing the current size, thereby adjusting the vibration absorption frequency in real time and widening the vibration absorption frequency band. When the anti-resonance point is close to the excitation frequency, the vibration absorption effect is best. The coil and the permanent magnet jointly provide an outer magnetic ring magnetic field, the permanent magnet provides a basic magnetic field, and the coil provides an adjustment magnetic field. The magnetic field strength is increased or decreased by changing the direction and size of the current, thereby changing the torque and torsional stiffness of the internal magnetic ring. The vibration absorption capacity can be changed by changing the length and number of magnets, the angle of the counterweight block, the number of coil turns, etc., so that the tool rod can be used in more types of tools and is suitable for more usage environments. During cutting, the counterweight block undergoes torsional vibration. Compared with linear vibration, its vibration range is increased and the vibration absorption effect is better. In addition, the overall structure is simple, compact, safe and reliable, and the tool rod can be adjusted in real time as the excitation environment changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is one of the three-dimensional structural schematic diagrams of an embodiment of the present invention.

[0016] Figure 2 This is the second schematic diagram of the three-dimensional structure of the embodiment of the present invention.

[0017] Figure 3 It is a schematic diagram of the main structure of an embodiment of the present invention.

[0018] Figure 4 1 is a schematic diagram of a cross-sectional structure of an embodiment of the present invention ( Figure 3 sectional view of the ).

[0019] Figure 5 yes Figure 4 AA cross-sectional structure diagram in.

[0020] Figure 6 yes Figure 5 Schematic diagram of the structure of the inner shell.

[0021] Figure 7 yes Figure 5 Schematic diagram of the structure of the middle and outer shell.

[0022] Reference numerals:

[0023] Counterweight block 1, plane 1-1, inner magnetic ring unit 2, inner shell 2-1, inner magnet through hole 2-11, inner magnet 2-2, outer magnetic ring unit 3, outer shell 3-1, outer magnet through slot 3-11, coil mounting slot 3-12, outer magnet 3-2, coil 3-3, connecting ring 4, center rod 5, counterweight rod 6, end cover 7, rubber ring 8, bearing 9, locking screw 10. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] Figure 1 The new electromagnetic semi-active vibration-damping tool arbor shown includes a counterweight block 1, an inner magnetic ring unit 2, an outer magnetic ring unit 3 and a center rod 5.

[0026] like Figure 4 As shown, a hollow counterweight rod 6 is coaxially mounted on the center rod, and the two ends of the counterweight rod are rotatably positioned on the outer circumference of the center rod through bearings 9, respectively. An inner and outer magnetic ring assembly is respectively mounted on the outside of the two axial ends of the counterweight rod, and a counterweight block 1 is fixed to the counterweight rod portion between the two inner and outer magnetic ring assemblies. The inner and outer magnetic ring assembly consists of an inner magnetic ring unit fixed on the outer circumference of the counterweight rod and an outer magnetic ring unit coaxially coated on the outer circumference of the inner magnetic ring unit. The counterweight block and the inner magnetic ring unit are both arranged on the counterweight rod, and the outer magnetic ring unit is fixed on the center rod; the inner and outer magnetic ring units are both annular structures and are coaxially arranged, and the inner magnetic ring unit is rotatably positioned between the counterweight rod and the outer magnetic ring unit; when the tool is working, the inner magnetic ring unit rotates around the axis of the center rod, and the outer magnetic ring unit provides torsional stiffness.

[0027] like Figure 5 As shown, the inner magnetic ring unit includes an inner shell 2-1 and a plurality of inner magnets 2-2. The inner shell is coaxially arranged on the counterweight rod, and the plurality of inner magnets are fixed to the wall of the inner shell and are evenly arranged around the axis of the inner shell. The outer magnetic ring unit includes an outer shell 3-1, a plurality of outer magnets 3-2, and a coil 3-3. The outer shell coaxially covers the inner shell and maintains a gap with the inner shell, and a plurality of outer magnets are arranged on the wall of the outer shell and are evenly arranged around the axis of the outer shell; each external magnet is wound around a coil to form a plurality of electromagnets. Furthermore, the coils on the plurality of external magnets are connected in sequence and then connected to the external power supply (preferably AC power).

[0028] The number of the inner magnets and the number of the outer magnets are both eight, and they are permanent magnets respectively; the outer magnets are wound around the coils to form eight electromagnets.

[0029] like Figure 7 As shown, the outer shell is a toroidal body, and its wall is provided with eight external magnet slots 3-11 symmetrical to the axis for mounting eight external magnets one by one; each external magnet slot through hole is parallel to the inner shell busbar and passes through the two end faces of the outer shell. A coil mounting slot 3-12 is provided between two adjacent external magnet slots for winding the coil, and each coil mounting slot passes through the inner wall of the outer shell through a notch to facilitate the winding of the coil.

[0030] like Figure 6 As shown, the inner shell is a circular ring, and its wall is provided with eight inner magnet through slots 2-11 symmetrical to the axis for mounting eight inner magnets one by one, and each inner magnet through slot is parallel to the inner shell busbar and passes through the two end faces of the inner shell.

[0031] The inner shell and the outer shell can be made of non-magnetic steel, aluminum or plastic.

[0032] like Figure 5 As shown, the directions of the magnetic flux lines of the outer magnet and the inner magnet are both radial to the tool; in the inner magnetic ring unit, the directions of the magnetic flux lines of two adjacent inner magnets are opposite.

[0033] In the outer magnetic ring unit, the magnetic flux lines of two adjacent outer magnets are in opposite directions, namely radial convergence (from the surroundings to the axis of the central rod) and radial divergence (from the axis of the central rod to the surroundings). In the natural state (non-powered state), the inner and outer magnets arranged in the same radial direction are aligned with each other and have the same magnetic flux lines. In the outer magnetic ring unit, each outer magnet is wrapped with a coil, and the winding directions of the two adjacent coils are opposite; after power is turned on, the magnetic field generated by the coil is in the same direction as the magnetic field of the wrapped outer magnet.

[0034] like Figure 4As shown, the counterweight block, the counterweight rod, and the inner magnetic ring unit can rotate together around the center rod; the outer magnetic ring unit is tightly fitted and fixed to the outer circumference of the end cover 7, and the end cover is fastened to the end of the center rod through the end nut (by Figure 4 It can be seen that: the end nuts at both ends respectively press the end covers, and the end covers press the inner ring of the bearing through the pads; the counterweight rod is tightly fixed with the outer rings of the bearings at both ends). The counterweight block is a semi-circular ring structure, which is fixed to the counterweight rod by locking screws 10 and connecting rings 4. The vibration absorption effect can be optimized by changing the angle of the counterweight block. The connecting ring is in the shape of a semi-circular ring sheet, and its inner ring surface fits on the counterweight rod. The two ends are fixed to the rectangular plane 1-1 (the plane parallel to the axis) of the counterweight block by locking screws.

[0035] Before processing, the boring tool housing needs to be coaxially installed on the outside of the counterweight rod; therefore, a rubber ring 8 is also installed on the end cover to seal between the boring tool housing and the end cover to prevent cutting fluid from entering the inside of the tool rod.

[0036] Working principle of the present invention:

[0037] The present invention is also provided with a tool housing on the outside, and the counterweight blocks are all located in the tool housing (such as a boring tool housing), and the center rod and the end cover are fixed to the machine tool with the tool housing; when the tool cuts metal, radial vibration (up and down vibration) occurs under the action of the cutting force, and the counterweight block undergoes torsional vibration due to inertia, and drives the inner magnetic ring unit to rotate at the same time; due to the torsion of the inner magnetic ring unit, the outer magnetic ring unit provides torsional rigidity for it to ensure the return of the inner magnetic ring unit; by adjusting the current of the coil, the torsional magnetic rigidity of the outer magnetic ring to the inner magnetic ring can be changed, thereby changing the natural frequency of the vibration absorber (counterweight block-counterweight rod-inner magnetic ring unit), so that the anti-resonance point of the amplitude-frequency response curve of the tool rod moves left and right, so that it has a good vibration absorption effect under different working environments (different excitation frequencies). The vibration absorption capacity and the vibration absorption working range can also be adjusted by changing the angle of the counterweight block, the number and length of the inner and outer magnets.

[0038] Finally, it should be noted that the above examples are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above examples, and many variations are possible. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A novel semi-active electromagnetic vibration-damping tool bar, comprising a center bar (5), characterized in that: The knife bar also includes a counterweight rod (6) which is rotatably sleeved and positioned on the center rod and has a counterweight block (1), and two inner and outer magnetic ring assemblies respectively mounted on two axial ends of the counterweight rod; the inner and outer magnetic ring assemblies include an inner magnetic ring unit (2) coaxially fixed on the counterweight rod and an outer magnetic ring unit (3) fixed on the center rod and coaxially sleeved outside the inner magnetic ring unit; The inner magnetic ring unit comprises an inner shell (2-1) coaxially fixed on the counterweight rod, and a plurality of inner magnets (2-2) uniformly arranged on the wall of the inner shell along the circumferential direction; the outer magnetic ring unit comprises an outer shell (3-1) coaxially arranged outside the inner shell and fixed to the center rod, and a plurality of outer magnets (3-2) uniformly arranged on the inner wall of the outer shell along the circumferential direction and respectively wound with coils (3-3); The directions of the magnetic flux lines of the inner magnet and the outer magnet are both radial, the directions of the magnetic flux lines of adjacent inner magnets are opposite, and the directions of the magnetic flux lines of adjacent outer magnets are also opposite.

2. The novel semi-active electromagnetic vibration damping tool bar according to claim 1 is characterized in that: The inner shell is a circular ring, and its wall is provided with a plurality of inner magnet through grooves (2-11) symmetrical to the axis and passing through the two end surfaces of the inner shell for mounting the inner magnets one by one; the outer shell is a circular ring, and its wall is provided with a plurality of outer magnet through grooves (3-11) symmetrical to the axis and passing through the two end surfaces of the outer shell for mounting the outer magnets one by one; a coil mounting groove (3-12) is provided between two adjacent outer magnet through grooves for winding the coil.

3. The novel semi-active electromagnetic vibration damping tool bar according to claim 2 is characterized in that: The coils on the plurality of external magnets are connected in sequence and then connected to the external power source.

4. The novel semi-active electromagnetic vibration damping tool bar according to claim 3 is characterized in that: In the non-powered state, the inner magnet and the outer magnet in the same radial direction are aligned with each other and the directions of the magnetic flux lines are the same.

5. The novel semi-active electromagnetic vibration damping tool bar according to claim 4 is characterized in that: The counterweight rod is rotatably positioned on the center rod through a bearing.

6. The novel semi-active electromagnetic vibration damping tool bar according to claim 5 is characterized in that: End covers (7) are fixed to both ends of the central rod, and the outer shell is tightly connected to the outer circumferential surface of the end cover.

7. The novel semi-active electromagnetic vibration damping tool bar according to claim 6 is characterized in that: The counterweight block is arranged on the counterweight rod and is located between two inner and outer magnetic ring assemblies.

8. The novel semi-active electromagnetic vibration damping tool bar according to claim 7 is characterized in that: The counterweight block is a semicircular ring body and is engaged on the counterweight rod through a plurality of connecting rings (4) connected thereto.

9. The novel semi-active electromagnetic vibration damping tool bar according to claim 8 is characterized in that: The connecting ring is a semicircular ring piece that is compatible with the arc surface of the counterweight rod, and the ends at both ends are respectively connected to the plane (1-1) of the counterweight block through locking screws.

10. The novel semi-active electromagnetic vibration-damping tool bar according to claim 9 is characterized in that: The central rod is a hollow rod through which coolant flows.

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