Passive self-feedback magnetorheological elastomer end mill damping anti-crash handle

Abstract

The application relates to the technical field of milling cutters, in particular to a passive self-feedback magnetorheological elastomer plug milling vibration reduction and tool breakage prevention handle, which comprises a handle body, a floating spindle, a pre-tightening unit, a magnetorheological damping unit and a self-feedback magnetic circuit adjusting unit; the floating spindle is in circumferential synchronous torque transmission with the handle body through a spline pair and can axially slide relatively; the pre-tightening unit is arranged between the handle body and the floating spindle; the magnetorheological damping unit comprises magnetorheological elastomers, the magnetorheological elastomers are annular, the inner ring of the magnetorheological elastomers is fixed relative to the floating spindle, the outer ring of the magnetorheological elastomers is fixed relative to the handle body, and the magnetorheological damping unit is used for providing radial shear vibration reduction damping and axial retreat buffer damping; the self-feedback magnetic circuit adjusting unit comprises a fixed permanent magnet ring and a follow-up permanent magnet ring. The passive self-feedback magnetorheological elastomer plug milling vibration reduction and tool breakage prevention handle can inhibit tool axial rebound oscillation during plug milling, reduce tool breakage risk and prolong tool service life.

Description

Technical Field

[0001] This invention relates to the field of milling cutter technology, specifically to a self-sourced feedback magnetorheological elastomer milling tool holder with vibration reduction and anti-breakage properties. Background Technology

[0002] In the valve manufacturing field, deep cavity and narrow groove structures such as valve body flow channels, valve seat sealing grooves, and valve core guide grooves are mostly machined using plunge milling. These workpieces are mostly made of cast steel, stainless steel, nickel-based high-temperature alloys, etc. The blanks often have defects such as casting hard skin, uneven allowance, and internal inclusions. The axial cutting load fluctuates violently during plunge milling, which can easily cause tool breakage, resulting in poor surface quality and short tool life, which seriously restricts the machining efficiency and yield of key valve parts.

[0003] Currently, most conventional milling cutter holders are rigid, one-piece structures without overload protection. When encountering sudden changes in allowance or hard inclusions, they are prone to chipping or breakage. Some cutter holders with axial relief structures rely solely on disc springs for unloading, lacking adaptive damping buffers. After relief, they are prone to axial rebound oscillation, which exacerbates the alternating impact on the cutting edge, making it difficult to effectively control the risk of chipping. Existing magnetorheological vibration damping cutter holders are only designed for radial vibration, lacking axial overload relief protection. They also rely heavily on coil excitation, resulting in complex wiring, poor reliability, and difficulty in adapting to the harsh working conditions of valve processing sites with high levels of oil and strong cutting impacts.

[0004] Therefore, how to suppress axial springback oscillation of the tool during the plunge milling process, reduce the risk of tool breakage, and improve tool life is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned shortcomings in current plunge milling processes by providing a self-feedback magnetorheological elastomer plunge milling vibration damping and anti-breakage tool holder, thereby suppressing axial springback oscillation of the tool during plunge milling, reducing the risk of tool breakage, and improving tool life.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A self-feedback magnetorheological elastomer milling tool holder with vibration reduction and anti-breakage features includes a tool holder body, a floating spindle, a preload unit, a magnetorheological damping unit, and a self-feedback magnetic circuit adjustment unit. The floating spindle transmits torque synchronously with the tool holder body in the circumferential direction through a spline pair, and can slide relative to it in the axial direction. The preload unit is disposed between the tool holder body and the floating spindle, and is used to provide a preload force along the axial direction of the floating spindle and toward the milling part, and can set the force threshold for overload triggering. The magnetorheological damping unit includes a magnetorheological elastomer, which is ring-shaped. The inner ring of the magnetorheological elastomer is fixed relative to the floating spindle, and the outer ring of the magnetorheological elastomer is fixed relative to the tool holder body. The magnetorheological damping unit is used to provide radial shear damping and axial relief buffer damping. The self-feedback magnetic circuit adjustment unit includes a fixed permanent magnet ring and a follower permanent magnet ring. The fixed permanent magnet ring is disposed on the tool holder body, and the follower permanent magnet ring is disposed on the floating spindle. The fixed permanent magnet ring and the follower permanent magnet ring are arranged opposite each other with the same pole, and there is an air gap between the fixed permanent magnet ring and the follower permanent magnet ring. When the floating spindle is loaded and retracts upward, the follower permanent magnet ring moves axially synchronously, thereby reducing the air gap and increasing the magnetic flux density passing through the magnetorheological elastic body to achieve adaptive negative feedback adjustment of damping.

[0007] As the preferred technical solution of this application, the magnetorheological elastomer is an anisotropic magnetorheological elastomer, with the internal magnetic particles arranged radially.

[0008] As the preferred technical solution of this application, the tool holder body is provided with a hollow first cavity, and the tool holder body is arranged in the first cavity.

[0009] As the preferred technical solution of this application, the magnetorheological damping unit further includes an inner magnetic sleeve and an outer magnetic sleeve. The inner magnetic sleeve is interference-fitted onto the floating main shaft, and the outer ring of the inner magnetic sleeve is bonded to the inner ring of the magnetorheological elastomer. The outer ring of the outer magnetic sleeve is fixed to the inner wall of the first cavity, and the inner ring of the outer magnetic sleeve is bonded to the outer ring of the magnetorheological elastomer.

[0010] As the preferred technical solution of this application, the following permanent magnet ring, magnetorheological elastomer and fixed permanent magnet ring are coaxially distributed, and the magnetorheological elastomer is located in the region between the following permanent magnet ring and the fixed permanent magnet ring in the axial direction along the tool holder body. The fixed permanent magnet ring is axially magnetized with the N pole facing down and the S pole facing up. The servo permanent magnet ring is axially magnetized with the S pole facing down and the N pole facing up. The outer diameters of both the fixed permanent magnet ring and the follower permanent magnet ring are smaller than the inner diameter of the magnetorheological elastomer.

[0011] As the preferred technical solution of this application, the spline pair includes a spline shaft and a spline sleeve. The spline shaft is disposed on a floating spindle, and the spline sleeve is disposed on the tool holder body. The spline shaft and the spline sleeve cooperate with each other.

[0012] As the preferred technical solution of this application, the preload unit includes a spring and an adjusting member. The spring is elastic, and the adjusting member is threadedly connected to the tool holder body. One end of the spring abuts against the adjusting member, and the other end abuts against the floating spindle. Rotating the adjusting member can change the compression of the spring, thereby adjusting the force threshold for overload triggering.

[0013] As a preferred technical solution of this application, the tool holder body is also provided with a limiting end cap, which is screwed into the lower end of the tool holder body to limit the maximum downward extension stroke of the floating spindle.

[0014] As the preferred technical solution of this application, a sealing ring is provided on the inner wall of the limiting end cover. The sealing ring is used to fit against the outer wall of the floating spindle to prevent dust, cutting fluid or iron filings from entering the first cavity from between the limiting end cover and the floating spindle.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the solution of this application, when the self-feedback magnetorheological elastomer plunge milling vibration damping and anti-breakage tool holder is in normal cutting steady state and there is no overload, the axial cutting force of the plunge milling is less than the total threshold for triggering axial overload. The floating spindle has no axial displacement and remains in a fixed position. The radial vibration generated by the plunge milling is transmitted to the magnetorheological elastomer through the floating spindle, causing radial shear deformation of the magnetorheological elastomer. The magnetostrictive particle chains inside the magnetorheological elastomer provide additional damping, consume vibration energy, suppress radial vibration, and reduce the risk of chatter and tool breakage. 2. During the milling process, if the tool holder is slightly overloaded due to uneven allowance or hard spots in the material, the axial cutting force slightly exceeds the total threshold for axial overload triggering. The floating spindle drives the tool to retract slightly upwards, with a retraction distance of 0-1mm. During this retraction, the moving permanent magnet ring moves upwards synchronously with the spindle, reducing the air gap between it and the fixed permanent magnet ring. The radial magnetic field increases as the air gap decreases, increasing the magnetic flux through the magnetorheological elastomer. The axial shear damping and stiffness of the magnetorheological elastomer automatically increase. This increased damping, in turn, hinders the retraction speed, consumes impact energy, and prevents rebound after rapid retraction. After the floating spindle retracts to a certain extent, the sum of the preload provided by the preload unit, the axial shear resistance of the magnetorheological elastomer, and the axial repulsive force between the fixed permanent magnet ring and the moving permanent magnet ring reaches a new dynamic balance with the cutting force. The tool stabilizes at the current position, the cutting depth automatically decreases, and the load falls back to the safe range. This allows for stepless continuous adjustment throughout the entire process, effectively reducing the impact on the tool. 3. When the tool holder of this application is subjected to severe impact overload due to a sudden large allowance or hard inclusion during the milling process, the axial cutting force exceeds the total threshold for axial overload triggering. The follower permanent magnet ring can move rapidly with the floating spindle, so that the follower permanent magnet ring quickly approaches the fixed permanent magnet ring. At this time, the air gap between the follower permanent magnet ring and the fixed permanent magnet ring decreases sharply, the magnetic field strength of the magnetorheological elastomer increases nonlinearly, and the damping of the magnetorheological elastomer can be increased instantaneously and significantly, forming a hard buffer effect, absorbing most of the impact kinetic energy, and avoiding rigid collision and tool breakage between the tool and the workpiece. In this case, the retraction stroke of the floating spindle can be 1-5mm. 4. After the hard point is passed or the allowance returns to normal, when the axial cutting force is less than the total threshold for axial overload triggering, the preload unit provides thrust to reset the floating spindle downwards. During its reset process, the moving permanent magnet ring moves downwards synchronously, the air gap increases, and the magnetorheological elastic damping automatically decreases, which makes the reset speed smooth, greatly reduces the downward impact load, and further reduces the probability of the cutting edge penetrating the workpiece and causing breakage. At the same time, after the reset is completed, it automatically returns to the initial cutting position and can continue normal machining without manual intervention. In addition, during the plunge milling process, it can suppress the axial springback oscillation of the tool, reduce the risk of tool breakage, and improve the tool life. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of one embodiment of a self-feedback magnetorheological elastomer insert milling vibration reduction and anti-breakage tool holder according to this application; Figure 2 This is a schematic diagram of the structure located at the self-feedback magnetic circuit adjustment unit in one embodiment of the self-feedback magnetorheological elastomer milling vibration reduction and anti-breakage tool holder of this application. Figure 3 This is a schematic diagram of the structure located at the spline pair in one embodiment of the self-source-feedback magnetorheological elastomer plunge milling vibration reduction and anti-breakage tool holder of this application; The diagram shows: 1-tool holder body, 2-floating spindle, 3-preload unit, 4-magnetorheological damping unit, 5-self-feedback magnetic circuit adjustment unit, 6-spline pair, 7-magnetorheological elastomer, 8-fixed permanent magnet ring, 9-follower permanent magnet ring, 10-first cavity, 11-inner magnetic sleeve, 12-outer magnetic sleeve, 13-spline shaft, 14-spline sleeve, 15-spring, 16-adjusting component, 17-limiting end cap, 18-sealing ring. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0018] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely illustrates some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. These terms are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] Example 1: This example provides a self-feedback magnetorheological elastomer 7-piece plunge milling tool holder with vibration damping and anti-breakage function. See [link to example]. Figures 1-3 As shown, it includes a tool holder body 1, a floating spindle 2, a preload unit 3, a magnetorheological damping unit 4, and a self-feedback magnetic circuit adjustment unit 5; The floating spindle 2 transmits torque synchronously with the tool holder body 1 in the circumferential direction through the spline pair 6, and can slide relative to it in the axial direction. The preload unit 3 is disposed between the tool holder body 1 and the floating spindle 2, and is used to provide a preload force along the axial direction of the floating spindle 2 and toward the milling part, and can set the force threshold for overload triggering. The magnetorheological damping unit 4 includes a magnetorheological elastomer 7, which is annular. The inner ring of the magnetorheological elastomer 7 is fixed relative to the floating spindle 2, and the outer ring of the magnetorheological elastomer 7 is fixed relative to the tool holder body 1. The magnetorheological damping unit 4 is used to provide radial shear damping and axial relief buffer damping. The self-feedback magnetic circuit adjustment unit 5 includes a fixed permanent magnet ring 8 and a follower permanent magnet ring 9. The fixed permanent magnet ring 8 is disposed on the tool holder body 1, and the follower permanent magnet ring 9 is disposed on the floating spindle 2. The fixed permanent magnet ring 8 and the follower permanent magnet ring 9 are arranged opposite each other with the same pole, and there is an air gap between the fixed permanent magnet ring 8 and the follower permanent magnet ring 9. When the floating spindle 2 is loaded and moves upward, the follower permanent magnet ring 9 moves axially synchronously to reduce the air gap, thereby increasing the magnetic flux density passing through the magnetorheological elastic body 7, so as to realize the adaptive negative feedback adjustment of damping.

[0023] As a preferred embodiment, based on the above method, the magnetorheological elastomer 7 is further an anisotropic magnetorheological elastomer, with the internal magnetic particles arranged radially.

[0024] In this application, the tool holder body 1 is fixedly connected to the machine tool spindle, and the floating spindle 2 is driven to rotate synchronously in the axial direction through the spline pair 6. The main cutting torque is borne by the spline pair 6, and the magnetorheological damping unit 4 does not participate in the torque transmission. The direction from top to bottom is the direction from the tool holder body 1 to the floating spindle 2. The preload force provided by the preload unit 3, the initial axial shear resistance of the magnetorheological elastomer 7, and the initial axial repulsive force between the fixed permanent magnet ring 8 and the follower permanent magnet ring 9 are superimposed in the same direction, and together constitute the total threshold for axial overload triggering. When the self-feedback magnetorheological elastomer 7 is in a normal cutting steady state and there is no overload, the axial cutting force of the plunge milling is less than the total threshold for triggering axial overload. The floating spindle 2 has no axial displacement and remains in a fixed position. The radial vibration generated by the plunge milling is transmitted to the magnetorheological elastomer 7 through the floating spindle 2, causing radial shear deformation of the magnetorheological elastomer 7. The magnetostrictive particle chain inside the magnetorheological elastomer 7 provides additional damping, consumes vibration energy, suppresses radial vibration, and reduces the risk of chatter and tool breakage. When the tool holder of this application is slightly overloaded due to uneven allowance or hard spots in the material during the milling process, the axial cutting force slightly exceeds the total threshold for axial overload triggering. The floating spindle 2 drives the tool to retract slightly upwards, with a retraction distance of 0-1mm. During this retraction, the follower permanent magnet ring 9 moves upwards synchronously with the spindle, reducing the air gap between it and the fixed permanent magnet ring 8. The radial magnetic field increases as the air gap decreases, increasing the magnetic flux through the magnetorheological elastomer 7. The axial shear damping and stiffness of the magnetorheological elastomer 7 automatically increase. This increased damping, in turn, hinders the retraction speed, consumes impact energy, and avoids rebound after rapid retraction. After the floating spindle 2 retracts to a certain extent, the sum of the preload force provided by the preload unit 3, the axial shear resistance of the magnetorheological elastomer 7, and the axial repulsive force between the fixed permanent magnet ring 8 and the follower permanent magnet ring 9 reaches a new dynamic balance with the cutting force. The tool stabilizes at the current position, the cutting depth automatically decreases, and the load falls back to the safe range. This allows for stepless continuous adjustment throughout the entire process, effectively reducing the impact on the tool. When the tool holder of this application is subjected to severe impact overload due to a sudden large allowance or hard inclusion during the milling process, the axial cutting force exceeds the total threshold for axial overload triggering. The follower permanent magnet ring 9 can move rapidly with the floating spindle 2, so that the follower permanent magnet ring 9 quickly approaches the fixed permanent magnet ring 8. At this time, the air gap between the follower permanent magnet ring 9 and the fixed permanent magnet ring 8 decreases sharply, and the magnetic field strength of the magnetorheological elastomer 7 increases nonlinearly. The damping of the magnetorheological elastomer 7 can be increased instantaneously and significantly, forming a hard buffer effect, absorbing most of the impact kinetic energy, and avoiding rigid collision and tool breakage between the tool and the workpiece. In this case, the retraction stroke of the floating spindle 2 can be 1-5mm. After the hard point is passed or the allowance returns to normal, when the axial cutting force is less than the total threshold for axial overload triggering, the preload unit 3 provides thrust to reset the floating spindle 2 downwards. During its reset process, the follower permanent magnet ring 9 moves downwards synchronously, the air gap increases, and the magnetorheological elastic damping automatically decreases, which makes the reset speed smooth, greatly reduces the downward impact load, and further reduces the probability of the cutting edge penetrating the workpiece and causing breakage. At the same time, after the reset is completed, it automatically returns to the initial cutting position and can continue normal machining without manual intervention. In addition, during the plunge milling process, it can suppress the axial springback oscillation of the tool, reduce the risk of tool breakage, and improve the tool life.

[0025] As a preferred embodiment, based on the above method, the handle body 1 is further provided with a hollow first cavity 10, and the handle body 1 is arranged in the first cavity 10.

[0026] By setting a hollow first cavity 10, it is convenient to arrange the tool holder body 1 inside the first cavity 10; a number of blades are circumferentially arranged at the end of the floating spindle 2.

[0027] Example 2: Based on the technical solution of Example 1, further details are provided below. Figure 2 and Figure 3 As shown, the magnetorheological damping unit 4 also includes an inner magnetic sleeve 11 and an outer magnetic sleeve 12. The inner magnetic sleeve 11 is interference-fitted onto the floating main shaft 2, and the outer ring of the inner magnetic sleeve 11 is bonded to the inner ring of the magnetorheological elastomer 7. The outer ring of the outer magnetic sleeve 12 is fixed on the inner wall of the first cavity 10, and the inner ring of the outer magnetic sleeve 12 is bonded to the outer ring of the magnetorheological elastomer 7.

[0028] As a preferred embodiment, based on the above method, the following permanent magnet ring 9, magnetorheological elastomer 7 and fixed permanent magnet ring 8 are further distributed coaxially, and the magnetorheological elastomer 7 is located in the region between the following permanent magnet ring 9 and the fixed permanent magnet ring 8 in the axial direction along the tool holder body 1. The fixed permanent magnet ring is axially magnetized with the N pole facing down and the S pole facing up. The servo permanent magnet ring is axially magnetized with the S pole facing down and the N pole facing up. The outer diameters of both the fixed permanent magnet ring 8 and the follower permanent magnet ring 9 are smaller than the inner diameter of the magnetorheological elastomer 7.

[0029] Furthermore, the magnetic circuit direction of the fixed permanent magnet ring 8 is as follows: after entering the inner magnetic sleeve 11 from the N pole of the fixed permanent magnet ring 8, it penetrates the magnetorheological elastic body 7 radially outward and enters the outer magnetic sleeve 12, and then enters the S pole of the fixed permanent magnet ring 8. The magnetic circuit direction of the follower permanent magnet ring 9 is as follows: from the N pole of the follower permanent magnet ring 9, it enters the inner magnetic sleeve 11 outward, penetrates the magnetorheological elastic body 7 radially outward, enters the outer magnetic sleeve 12, and then enters the S pole of the follower permanent magnet ring 9. Its inner magnetic sleeve 11 and outer magnetic sleeve 12 can reduce magnetic resistance, which is more conducive to the magnetic field lines passing through the magnetorheological elastic body 7 radially. Among them, the inner and outer diameters and axial thicknesses of the moving permanent magnet ring 9 and the fixed permanent magnet ring 8 can be the same. Meanwhile, when the self-feedback magnetorheological elastomer 7 milling vibration damping and anti-breakage tool holder is in normal cutting steady state and there is no overload, the air gap length between the fixed permanent magnet ring 8 and the moving permanent magnet ring 9 is ≤ the axial thickness of the moving permanent magnet ring 9 or the fixed permanent magnet ring 8, and the air gap length is ≤ 1 / 3 of the outer diameter of the fixed permanent magnet ring 8 or the moving permanent magnet ring 9. This facilitates the nonlinear increase of the magnetic flux density passing through the magnetorheological elastomer 7 as the air gap between the moving permanent magnet ring 9 and the fixed permanent magnet ring 8 gradually decreases.

[0030] As a preferred embodiment, based on the above method, the spline pair 6 further includes a spline shaft 13 and a spline sleeve 14. The spline shaft 13 is disposed on the floating spindle 2, and the spline sleeve 14 is disposed on the tool holder body 1. The spline shaft 13 and the spline sleeve 14 cooperate with each other.

[0031] In a preferred embodiment, based on the above method, the preload unit 3 further includes a spring 15 and an adjusting member 16. The spring 15 is elastic, and the adjusting member 16 is threadedly connected to the tool holder body 1. One end of the spring 15 abuts against the adjusting member 16, and the other end abuts against the floating spindle 2. Rotating the adjusting member 16 can change the compression of the spring 15, thereby adjusting the force threshold for overload triggering.

[0032] When the adjusting member 16 is rotated relative to the tool holder body 1, the adjusting member 16 can be moved along its own axis, thereby changing the distance between the adjusting member 16 and the floating spindle 2, which makes it easier to adjust the compression of the spring 15, and thus makes it easier to adjust the force threshold of overload triggering. At the same time, the adjustment range of its force threshold is 500N-3000N. Meanwhile, in this application, when the self-feedback magnetorheological elastomer 7 milling vibration damping and anti-breakage tool holder is in normal cutting steady state and there is no overload, the axial repulsive force between the fixed permanent magnet ring 8 and the follower permanent magnet ring 9 is much smaller than the overload triggering force threshold corresponding to the preload unit 3, that is, the axial repulsive force between the fixed permanent magnet ring 8 and the follower permanent magnet ring 9 is ≤1 / 10 of the overload triggering force threshold corresponding to the preload unit 3.

[0033] Example 3: Based on the technical solution of Example 2, further details are provided below. Figure 3 As shown, the tool holder body 1 is also provided with a limiting end cap 17, which is screwed into the lower end of the tool holder body 1 to limit the maximum downward extension stroke of the floating spindle 2.

[0034] Furthermore, by setting a limiting end cap 17, during the assembly process, the limiting end cap 17 is screwed into the lower end of the tool holder body 1, and the lower end of the tool holder body 1 is the end of the tool holder body 1 facing the milling part. In this way, when the self-generated feedback magnetorheological elastomer 7 milling vibration damping and anti-breakage tool holder is in a normal cutting steady state and there is no overload, the end of the floating spindle 2 abuts against the limiting end cap 17, so as to limit the position of the floating spindle 2, thereby facilitating the limitation of the maximum downward extension stroke of the floating spindle 2.

[0035] As a preferred embodiment, based on the above method, a sealing ring 18 is further provided on the inner side wall of the limiting end cover 17. The sealing ring 18 is used to fit against the outer wall of the floating spindle 2 to prevent dust, cutting fluid or iron filings from entering the first cavity 10 from between the limiting end cover 17 and the floating spindle 2.

[0036] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described herein. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present invention, as well as all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present invention.

Claims

1. A self-feedback magnetorheological elastomer milling tool holder with vibration damping and anti-breakage properties, characterized in that: It includes the tool holder body, floating spindle, preload unit, magnetorheological damping unit, and self-feedback magnetic circuit adjustment unit; The floating spindle transmits torque synchronously with the tool holder body in the circumferential direction through a spline pair, and can slide relative to it in the axial direction. The preload unit is disposed between the tool holder body and the floating spindle, and is used to provide a preload force along the axial direction of the floating spindle and toward the milling part, and can set the force threshold for overload triggering. The magnetorheological damping unit includes a magnetorheological elastomer, which is ring-shaped. The inner ring of the magnetorheological elastomer is fixed relative to the floating spindle, and the outer ring of the magnetorheological elastomer is fixed relative to the tool holder body. The magnetorheological damping unit is used to provide radial shear damping and axial relief buffer damping. The self-feedback magnetic circuit adjustment unit includes a fixed permanent magnet ring and a follower permanent magnet ring. The fixed permanent magnet ring is disposed on the tool holder body, and the follower permanent magnet ring is disposed on the floating spindle. The fixed permanent magnet ring and the follower permanent magnet ring are arranged opposite each other with the same pole, and there is an air gap between the fixed permanent magnet ring and the follower permanent magnet ring. When the floating spindle is loaded and retracts upward, the follower permanent magnet ring moves axially synchronously, thereby reducing the air gap and increasing the magnetic flux density passing through the magnetorheological elastic body to achieve adaptive negative feedback adjustment of damping.

2. The self-feedback magnetorheological elastomer milling tool holder with vibration damping and anti-breakage as described in claim 1, characterized in that: The magnetorheological elastomer is an anisotropic magnetorheological elastomer with internal magnetic particles arranged radially.

3. The self-feedback magnetorheological elastomer milling tool holder for vibration reduction and anti-breakage as described in claim 2, characterized in that: The handle body has a hollow first cavity, and the handle body is arranged in the first cavity.

4. The self-feedback magnetorheological elastomer milling tool holder with vibration damping and anti-breakage as described in claim 3, characterized in that: The magnetorheological damping unit also includes an inner magnetic sleeve and an outer magnetic sleeve. The inner magnetic sleeve is interference-fitted onto the floating main shaft, and the outer ring of the inner magnetic sleeve is bonded to the inner ring of the magnetorheological elastomer. The outer ring of the outer magnetic sleeve is fixed to the inner wall of the first cavity, and the inner ring of the outer magnetic sleeve is bonded to the outer ring of the magnetorheological elastomer.

5. The self-feedback magnetorheological elastomer milling tool holder for vibration reduction and anti-breakage as described in claim 4, characterized in that: The following permanent magnet ring, magnetorheological elastomer and fixed permanent magnet ring are coaxially distributed, and the magnetorheological elastomer is located in the region between the following permanent magnet ring and the fixed permanent magnet ring along the axial direction of the tool holder body. The fixed permanent magnet ring is axially magnetized with the N pole facing down and the S pole facing up. The servo permanent magnet ring is axially magnetized with the S pole facing down and the N pole facing up. The outer diameters of both the fixed permanent magnet ring and the follower permanent magnet ring are smaller than the inner diameter of the magnetorheological elastomer.

6. The self-feedback magnetorheological elastomer milling tool holder for vibration reduction and anti-breakage as described in claim 5, characterized in that: The spline pair includes a spline shaft and a spline sleeve. The spline shaft is mounted on a floating spindle, and the spline sleeve is mounted on the tool holder body. The spline shaft and the spline sleeve cooperate with each other.

7. The self-feedback magnetorheological elastomer milling tool holder for vibration reduction and anti-breakage as described in claim 6, characterized in that: The preload unit includes a spring and an adjusting member. The spring is elastic, and the adjusting member is threaded onto the tool holder body. One end of the spring abuts against the adjusting member, and the other end abuts against the floating spindle. Rotating the adjusting member can change the compression of the spring, thereby adjusting the overload trigger force threshold.

8. The self-feedback magnetorheological elastomer milling tool holder for vibration reduction and anti-breakage as described in claim 7, characterized in that: The tool holder body is also provided with a limiting end cap, which is screwed into the lower end of the tool holder body to limit the maximum downward extension stroke of the floating spindle.

9. The self-feedback magnetorheological elastomer milling tool holder for vibration reduction and anti-breakage as described in claim 8, characterized in that: A sealing ring is provided on the inner wall of the limiting end cover. The sealing ring is used to fit against the outer wall of the floating spindle to prevent dust, cutting fluid or iron filings from entering the first cavity from between the limiting end cover and the floating spindle.

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