CN114192855A

CN114192855A - Vibration reduction milling cutter

Info

Publication number: CN114192855A
Application number: CN202111464442.8A
Authority: CN
Inventors: 杨毅青; 申睿
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2021-12-02
Filing date: 2021-12-02
Publication date: 2022-03-18
Anticipated expiration: 2041-12-02
Also published as: CN114192855B

Abstract

The invention relates to a vibration reduction milling cutter, which belongs to the technical field of machining and manufacturing and comprises a milling cutter head, a cutter bar, a connecting frame and a damper, wherein a first connecting rod is coaxially arranged on the end surface of one end of the milling cutter head; a second connecting rod is coaxially arranged on the end face of one end of the cutter bar; a cavity is formed in the connecting frame, one end of the connecting frame is connected with the milling cutter head, the other end of the connecting frame is connected with the cutter bar, the first connecting rod and the second connecting rod are both positioned in the cavity, and the first connecting rod and the second connecting rod are oppositely arranged; the damper is installed in the cavity, and the damper includes quality piece and magnet group, and the magnet group is installed on the quality piece, and the relative tip of first connecting rod and second connecting rod respectively with the tip looks butt at the both ends of quality piece. The milling cutter provided by the invention has the effect of solving the problem of milling cutter chatter in high-speed milling of the milling cutter with a large length-diameter ratio.

Description

Vibration reduction milling cutter

Technical Field

The invention relates to the technical field of machining and manufacturing, in particular to a vibration reduction milling cutter.

Background

This section provides background information related to the present disclosure only and is not necessarily prior art.

A milling cutter is a rotary cutter used for milling and provided with one or more cutter teeth, and each cutter tooth cuts off the allowance of a workpiece intermittently in sequence during operation. When selecting the milling cutter, the cutter with the minimum length-diameter ratio meeting the processing requirement is selected to obtain the highest processing efficiency. Deep cavity parts are widely used in the industries of aviation, aerospace, automobiles and the like. When the inner surface of a deep cavity part is machined, a milling cutter with a large length-diameter ratio is needed. However, the large length-diameter ratio of the cutter is longer in overhang and poor in rigidity, and the chatter phenomenon often occurs in the cutting process. The chattering can cause chatter marks on the machined surface of the part, and the surface roughness of the part is poor. The vibration reduction tool can effectively inhibit vibration in the cutting process. At present, when a cutter bar with a vibration suppression frequency adjusting function is adjusted, an operator needs to have relevant theoretical knowledge. Therefore, in practical production and processing, a tool bar with a simple structure and capable of adjusting damping frequency through simple operation is needed.

The principles of the existing damping schemes are mainly divided into active damping and passive damping. The active vibration reduction scheme usually occupies a large volume, and the device is complex and difficult to control; the passive vibration reduction does not need an additional device, and the implementation is convenient and the effect is obvious. Passive vibration reduction can be divided into energy consumption vibration reduction and dynamic vibration absorption, the energy consumption vibration reduction absorbs vibration energy through collision of particle damping, friction of a friction rod and a cutter bar and the like to achieve the purpose of vibration reduction, but the working noise is high, and the vibration reduction effect is limited; the dynamic vibration absorption can accurately inhibit vibration in a working bandwidth, the vibration absorption effect is good, but most of the conventional dynamic vibration absorption cutters adopt rubber as a rigidity element, the aging of rubber materials seriously affects the vibration inhibition performance, and even eccentric mass can be generated in a milling cutter to cause the milling cutter to vibrate.

In addition, other types of rigid element implementations exist in the prior art, but the structure is complex, and when the parts are milled at high speed, the contact surface between the parts is too much, and unnecessary vibration is still introduced.

Disclosure of Invention

The invention aims to at least solve the problem of chatter of a milling cutter with a large length-diameter ratio in high-speed milling. The purpose is realized by the following technical scheme:

a first aspect of the invention provides a vibration-damping milling cutter comprising

The end face of one end of the milling head is coaxially provided with a first connecting rod, and the first connecting rod and the milling head are integrally formed;

a cutter bar; a second connecting rod is coaxially arranged on the end face of one end of the cutter bar, and the second connecting rod and the cutter bar are integrally formed;

the connecting frame is internally provided with a cavity, one end of the connecting frame is connected with the milling cutter head, the other end of the connecting frame is connected with the cutter bar, the first connecting rod and the second connecting rod are both positioned in the cavity, and the first connecting rod and the second connecting rod are oppositely arranged;

the damper is installed in the cavity and comprises a mass block and a magnet group, the magnet group is installed on the mass block, and the end parts, opposite to the first connecting rod and the second connecting rod, of the first connecting rod are respectively abutted to the end parts of the two ends of the mass block.

According to the vibration reduction milling cutter, the first connecting rod and the second connecting rod which are integrally formed with the milling cutter head and the cutter bar are arranged on the milling cutter head and the cutter bar, so that the eccentric mass of a milling cutter revolving body is greatly reduced, and the eccentric mass generated when the milling cutter mills at high speed is smaller; meanwhile, the damper, the first connecting rod and the second connecting rod jointly form the dynamic vibration absorber, wherein the damping effect is realized by generating an eddy current through the connecting frame cutting magnet group. The cutter bar is matched with the damper, so that the milling vibration of the milling cutter is attenuated, and the problem of milling cutter chatter in high-speed milling of the milling cutter with a large length-diameter ratio is solved.

In addition, the vibration reduction milling cutter according to the invention can also have the following additional technical features:

in some embodiments of the present invention, the magnet assembly includes a magnet ring and a multi-stage magnetic ring, and the magnet ring and the multi-stage magnetic ring are stacked in layers.

In some embodiments of the present invention, at least two sets of the magnet sets are provided, and at least two sets of the magnet sets are respectively installed at two ends of the mass block.

In some embodiments of the present invention, the end portions of the two ends of the mass block are respectively provided with a step, and at least two sets of the magnet sets are respectively sleeved on the mass block and abut against the steps.

In some embodiments of the present invention, an end of the first connecting rod abutting against the mass block is provided with a first pointed top end, and an end of the second connecting rod abutting against the mass block is provided with a second pointed top end.

In some embodiments of the present invention, a first mounting seat and a second mounting seat are coaxially and respectively formed on end surfaces of two ends of the mass block, and the first pointed end is inserted into the first mounting seat and the second pointed end is inserted into the second mounting seat.

In some embodiments of the present invention, a connection position of the first link and the first pointed top end and a connection position of the first link and the milling head are provided with a first round angle; and a second round angle is arranged at the connecting position of the second connecting rod and the second pointed top end and the connecting position of the second connecting rod and the cutter rod.

In some embodiments of the invention, the milling head is threadably connected to the attachment frame.

In some embodiments of the invention, the tool bar is threadedly coupled to the coupling frame.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like parts are designated by like reference numerals throughout the drawings. In the drawings:

FIG. 1 is a schematic overall sectional structure of a vibration reduction milling cutter;

FIG. 2 is a schematic view of an overall cross-sectional structure of the second connecting rod of FIG. 1 after replacing the tool bars with different length-diameter ratios;

FIG. 3 is a schematic view of the overall structure of the magnet assembly of FIG. 1;

FIG. 4 is a schematic view of the magnet ring of FIG. 3;

fig. 5 is a schematic view of the overall structure of the multi-stage magnetic ring shown in fig. 3.

Reference numerals:

1. a milling head; 10. a first link; 11. a first pointed tip; 2. a cutter bar; 20. a second link; 21. a second pointed tip; 3. a connecting frame; 30. a cavity; 4. a damper; 40. a mass block; 400. a step; 401. a first mounting seat; 402. a second mounting seat; 41. a magnet group; 410. a magnet ring; 411. a multi-stage magnetic ring; 5. a first rounded corner; 6. a second rounded corner.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless specifically identified as an order of performance. It should also be understood that additional or alternative steps may be used.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For convenience of description, spatially relative terms, such as "inner", "outer", "lower", "below", "upper", "above", and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" can include both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

As shown in fig. 1 to 5, the vibration damping milling cutter of the present embodiment includes

The end face of one end of the milling cutter head 1 is coaxially provided with a first connecting rod 10, and the first connecting rod 10 and the milling cutter head 1 are integrally formed;

a cutter bar 2; a second connecting rod 20 is coaxially arranged on the end face of one end of the cutter bar 2, and the second connecting rod 20 and the cutter bar 2 are integrally formed;

the milling cutter comprises a connecting frame 3, wherein a cavity 30 is formed in the connecting frame 3, one end of the connecting frame 3 is connected with a milling cutter head 1, the other end of the connecting frame 3 is connected with a cutter bar 2, a first connecting rod 10 and a second connecting rod 20 are both positioned in the cavity 30, and the first connecting rod 10 and the second connecting rod 20 are arranged oppositely;

the damper 4 is installed in the cavity 30, the damper 4 comprises a mass block 40 and a

magnet group

41, 41 the magnet group is installed on the mass block 40, and the opposite ends of the first connecting rod 10 and the second connecting rod 20 are respectively abutted to the ends of the two ends of the mass block 40.

Specifically, in this embodiment, the vibration reduction milling cutter includes a milling cutter head 1, a connecting frame 3, a cutter bar 2 and a damper 4 installed inside the connecting frame 3, which are coaxially connected in sequence, a cavity 30 coaxial with the connecting frame 3 is opened inside the connecting frame 3, and the damper 4 is coaxially installed inside the cavity 30. The material of the connecting frame 3 and the cutter bar 2 is tool steel H15, which has high rigidity, and the connecting frame 3 has ferromagnetism. The mass block 40 is made of a tungsten block, which is environment-friendly, has light pollution to production environment, has high density, is easy to control weight distribution, and has good corrosion resistance and long service life. The magnet set 41 is fixed on the mass block 40 and generates a magnetic field. The damper 4, together with the first link 10 and the second link 20, constitutes a dynamic vibration absorber that absorbs vibrations of the tool. When the damper 4 vibrates, the connecting frame 3 cuts the axial magnetic field generated by the magnet group 41, and generates an eddy current, thereby achieving a damping effect.

The non-blade end of the milling cutter head 1 is provided with a first connecting rod 10 fixedly arranged on the milling cutter head 1, the first connecting rod 10 is obtained by processing a blank of the milling cutter head 1 through a forming turning tool, the coaxiality of the first connecting rod 10 and the milling cutter head 1 is high, and the diameter of the first connecting rod 10 is fixed. The end face of the cutter bar 2 facing the connecting frame 3 is provided with a second connecting rod 20, the second connecting rod 20 is obtained by processing a blank of the cutter bar 2 through a forming lathe tool, and the coaxiality of the second connecting rod 20 and the cutter bar 2 is high. It should be noted that, the first connecting rod 10 and the second connecting rod 20 are both rigid rods, and compared with the conventional dynamic vibration absorption tool that uses rubber as a rigid element, the first connecting rod 10 and the second connecting rod 20 have the advantages of being not easy to age and deform, the eccentric mass generated during high-speed milling is smaller, the limit rotation speed of the milling cutter is higher, and the vibration and noise during milling are also greatly reduced.

According to the vibration reduction milling cutter, the first connecting rod 10 and the second connecting rod 20 which are integrally formed with the milling cutter head 1 and the cutter bar 2 are arranged on the milling cutter head, so that the eccentric mass of a milling cutter revolving body is greatly reduced, and the eccentric mass generated during high-speed milling of the milling cutter is smaller; meanwhile, the damper 4, the first link 10, and the second link 20 together constitute a dynamic vibration absorber, wherein damping is achieved by generating eddy currents by cutting the magnet group 41 through the link 3. The cutter bar 2 is matched with the damper 4, so that the milling vibration of the milling cutter is attenuated, and the problem of milling cutter chatter in high-speed milling of the milling cutter with a large length-diameter ratio is solved.

In some embodiments of the present invention, the magnet assembly 41 includes a magnet ring 410 and a multi-stage magnetic ring 411, and the magnet ring 410 and the multi-stage magnetic ring 411 are stacked in layers.

In some embodiments of the present invention, at least two sets of the magnet sets 41 are provided, and at least two sets of the magnet sets 41 are respectively installed at two ends of the mass block 40.

Furthermore, steps 400 are respectively disposed at the end portions of the two ends of the mass block 40, and at least two groups of magnet groups 41 are respectively sleeved on the mass block 40 and abutted against the steps 400.

Specifically, the magnet ring 410 is a general ring magnet, the magnet ring 410 and the multi-stage magnetic ring 411 are stacked to form the magnet group 41, the magnetic induction lines along the axial direction are arranged inside the magnet ring 410, the magnetic induction lines along the radial direction are arranged inside the multi-stage magnetic ring 411, the two magnetic induction lines are perpendicular to each other, and high external magnetic field strength is generated after the two magnetic induction lines are staggered (as shown in fig. 3). In this embodiment, four sets of magnet sets 41 are provided, and two sets of magnet sets are respectively sleeved at two end portions of the mass block 40, wherein the magnet set 41 at a position of each set close to the step 400 of the mass block 40 is attached to the step 400 in a sticking manner. The remaining magnet groups 41 are attracted strongly to the adjacent magnet groups 41, and combined to form the damper 4. When the vibration reduction milling cutter vibrates, the connecting frame 3 cuts the axial magnetic field generated by the magnet group 41 to generate an eddy current, so that the damping effect is achieved. The magnetic ring laminated structure arranged in this way greatly enhances the axial magnetic field intensity of the magnet group 41, greatly improves the number of magnetic induction lines cut by the ferromagnetic connecting frame 3 when the milling cutter is used, and greatly improves the damping efficiency.

It is worth mentioning that, since the length-diameter ratio of the tool bar 2 is determined according to the hole depth requirement of the processed part, the length-diameter ratio is as small as possible under the condition of meeting the processing requirement. For the cutter bars 2 with different specifications and length-diameter ratios, when the length-diameter ratio of the cutter bar 2 is changed, the dynamic characteristic of the cutter is changed, and the diameter of the second connecting rod 20 fixedly arranged on the cutter bar 2 is calculated according to the dynamic vibration absorption principle, so that the diameters of the second connecting rods 20 fixedly connected with the cutter bars 2 with different specifications are different. The diameter of the second connecting rod 20 determines the vibration frequency of the damper 4, the milling cutter integrates the frequency modulation device on the replaced cutter bar 2, the replaced cutter bar 2 can directly obtain the precisely tuned vibration reduction milling cutter, additional tuning on the damper 4 is not needed, and the steps of dynamic testing and tuning on the cutter are omitted; and the number of parts constituting the frequency-tunable milling cutter is greatly reduced. When the length-diameter ratio of the milling cutter is changed by replacing the cutter bar 2, the diameter of the second connecting rod 20 fixedly connected with the cutter bar 2 is changed along with the replacement of the cutter bar 2, but the size of the first connecting rod 10 fixedly connected with the milling cutter head 1 does not need to be changed, so that the milling cutter head 1 does not need to be replaced, and the cost of the cutter is saved.

In some embodiments of the present invention, the end of the first connecting rod 10 abutting the mass 40 is provided with a first pointed tip 11, and the end of the second connecting rod 20 abutting the mass 40 is provided with a second pointed tip 21. Specifically, the first pointed top end 11 and the second pointed top end 21 are both provided at opposite ends of the first connecting rod 10 and the second connecting rod 20 in a tapered shape, and the tip portions of the first pointed top end 11 and the second pointed top end 21 are both abutted on end surfaces of both ends of the mass block 40. The arrangement of the first sharp top end 11 and the second sharp top end 21 enables the damper 4 to be higher in coaxiality with the milling cutter head 1 and the cutter bar 2, reduces eccentric mass, further reduces vibration and noise during milling cutter machining, and improves reliability of the device.

In some embodiments of the present invention, the end surfaces of the two ends of the mass block 40 are coaxially provided with a first mounting seat 401 and a second mounting seat 402, and the first pointed top end 11 is inserted into the first mounting seat 401 and the second pointed top end 21 is inserted into the second mounting seat 402. Specifically, the end surfaces of the two ends of the mass block 40 are respectively provided with a first mounting seat 401 and a second mounting seat 402 which are matched with the first pointed top end 11 and the second pointed top end 21, the first mounting seat is a conical mounting seat matched with the first pointed top end, and the second mounting seat is a conical mounting seat matched with the second pointed top end. When the tool is mounted, the tip portion of the first pointed tip 11 is inserted into the first mounting seat 401, and the tip portion of the second pointed tip 21 is inserted into the second mounting seat 402. When the milling cutter works, the first mounting seat 401 and the second mounting seat 402 always keep the high coaxiality of the first sharp top end 11 and the second sharp top end 21, the phenomena of eccentric mass increase, noise and vibration caused by relative dislocation of the first sharp top end 11 and the second sharp top end 21 are avoided, the surface quality of parts is improved, and the reliability of the device is further improved.

In some embodiments of the present invention, the connection position of the first link 10 and the first pointed top end 11 and the connection position of the first link 10 and the milling head 1 are provided with the first rounded corner 5; the connecting position of the second connecting rod 20 and the second sharp top end 21 and the connecting position of the second connecting rod 20 and the cutter bar 2 are provided with second round corners 6. Specifically, because there is the diameter sudden change between first link 10 and first sharp top end 11, first link 10 and milling cutter head 1, set up first fillet 5 at the junction between first link 10 and first sharp top end 11, first link 10 and milling cutter head 1 to reduce stress concentration, avoid the device to be damaged, reduce economic cost. Similarly, the second round angle 6 is arranged at the connecting position between the second connecting rod 20 and the second sharp top end 21 and between the second connecting rod 20 and the cutter bar 2, so that stress concentration is reduced, the device is prevented from being damaged, and the economic cost is reduced.

In some embodiments of the invention, milling head 1 is threadedly coupled to attachment frame 3.

In some embodiments of the invention, the tool shank 2 is threadedly coupled to the coupling frame 3.

Specifically, the inner peripheral surface of link 3 both ends tip all is provided with the internal thread, and milling cutter head 1 and cutter arbor 2 all are provided with the external screw thread with the internal thread adaptation towards the outer peripheral surface of link 3 one end. During installation, the milling head 1 and the cutter bar 2 are screwed into the connecting frame 3 to complete assembly. The arrangement of threaded connection is convenient for mounting and dismounting the milling cutter head 1 and the cutter bar 2, and the working efficiency is improved; meanwhile, when the device is maintained and replaced, only part of parts can be replaced independently, and the economic cost is reduced.

Further, the direction of the thread on the milling head 1 is the same as the direction of rotation of the milling cutter. Specifically, when milling cutter is milling process, the moment of torsion that milling cutter received can make threaded connection self-tightening, has avoided milling cutter head 1 to break away from the device in the course of working, causes the injury to near staff, has further improved the reliability of device.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A vibration damping milling cutter is characterized by comprising

the end face of one end of the cutter bar is coaxially provided with a second connecting rod, and the second connecting rod and the cutter bar are integrally formed;

2. The vibration reducing milling cutter according to claim 1, wherein the magnet assembly includes a magnet ring and a plurality of stages of magnet rings, the magnet ring and the plurality of stages of magnet rings being arranged in a layered stack.

3. The vibration-damping milling cutter according to claim 2, wherein the magnet groups are provided in at least two groups, and the at least two groups of magnet groups are respectively mounted on both ends of the mass.

4. The vibration-damping milling cutter according to claim 3, wherein steps are provided at ends of both ends of the mass, and at least two sets of the magnet sets are provided to be fitted over the mass and abutted against the steps, respectively.

5. The vibration reducing milling cutter according to claim 1, wherein an end of the first link abutting the mass is provided with a first pointed tip, and an end of the second link abutting the mass is provided with a second pointed tip.

6. The vibration damping milling cutter according to claim 5, wherein the end surfaces of the two ends of the mass block are coaxially provided with a first mounting seat and a second mounting seat, respectively, and the first pointed end is inserted into the first mounting seat and the second pointed end is inserted into the second mounting seat.

7. The vibration reducing milling cutter according to claim 5, wherein a connecting position of the first link to the first pointed tip end and a connecting position of the first link to the milling head are each provided with a first rounded corner; and a second round angle is arranged at the connecting position of the second connecting rod and the second pointed top end and the connecting position of the second connecting rod and the cutter rod.

8. The vibration reducing milling cutter according to claim 1, wherein the milling head is threadedly connected to the connecting frame.

9. The vibration reducing milling cutter according to claim 1, wherein the cutter bar is threadedly connected to the connecting bracket.