KR102568286B1 - Lightweight and vibration-free tool holder and machine tool including the same - Google Patents

Abstract

An embodiment of the present invention provides a tool holder capable of reducing weight and damping vibration. A tool holder capable of reducing weight and damping according to an embodiment of the present invention includes a tool fixing unit to which a tool is coupled; A spindle coupling unit connected to the tool fixing unit and coupled to the spindle; and a lightweight vibration damping unit provided by laminating metal between the tool fixing unit and the spindle coupling unit, wherein the lightweight vibration damping unit includes a plurality of first metal layers stacked and spaced apart from each other; and a second metal layer including a plurality of support bars connecting the plurality of first metal layers, wherein the lightweight vibration damping unit is formed by 3D printing.

Description

Light weight and damping tool holder and machine tool equipped with the same {LIGHTWEIGHT AND VIBRATION-FREE TOOL HOLDER AND MACHINE TOOL INCLUDING THE SAME}

The present invention relates to a tool holder capable of reducing weight and damping vibration, and more particularly, to a tool holder capable of reducing weight and damping vibration manufactured to reduce the weight of tool work and preventing vibration, and to a machine tool having the same.

In general, machine tools are used for the purpose of processing metal workpieces into desired shapes and dimensions using appropriate tools by various cutting or non-cutting processing methods, such as CNC (Computerized Numerical Control) lathes or semi-automatic machines. There are types such as NC machines or machining centers.

In such a machine tool, a tool holder, which is a device coupled to a spindle, connects the spindle and a tool, and fixes the tool, is provided.

Both precision machine tools and advanced cutting tools provide excellent metal cutting productivity. In this case, the connection between the cutting tool and the machine spindle (tool holder) is important to fully realize productivity.

Tool manufacturers offer a variety of toolholder styles, each designed for optimal performance in a specific machining application.

Therefore, machine shops must select toolholders according to the specific task and the production parts of the plant, but they are only looking to obtain state-of-the-art machine technology and cutting tool materials, and the task is to select, apply and maintain the optimal toolholder for specific production requirements. Work is often neglected.

For example, toolholders designed to perform high-speed finishing operations often lack the necessary rigidity and strength to effectively deep rough rough raw cast steel. Conversely, holders for roughing are generally inferior in terms of balancing smooth operation at high speeds in finishing operations.

Also, roughing holders are rugged in design and bulky, which can make it difficult to access delicate or deep parts. Robust workpiece materials require tool holders with high strength and rigidity. In addition, the function of damping vibration and delivering coolant is also an important selection criterion.

If an operator uses an unsuitable toolholder, it can lead to excessive wear on the machine tool spindle, shortened tool life, increased tool breakage, dimensional errors and scrapped parts. Of course, for non-critical jobs, economical tool holders can produce satisfactory results. However, in operations where repeatability is essential, the part yield is low, especially if expensive workpieces have to be discarded.

On the other hand, when a severe external force (eg, impact in the direction of the shaft center) is applied to the main shaft spindle to which the abrasive member is coupled during the polishing process, there is a problem in that the abrasive member having high hardness is damaged or fatigue accumulation is applied to the main shaft spindle. In addition, there is a problem in that the abrasive member is frequently replaced or equipment is frequently repaired, resulting in an increase in the tact time of the polishing process and a decrease in productivity.

In the case of conventional parts processing, milling cutter bodies cannot be applied to high-speed processing due to the heavy weight of metal materials, and cause productivity problems during various processes, such as non-production time during tool replacement and increased energy and load during spindle acceleration/deceleration.

In existing tool holders, the above problems occurred because it was difficult to reduce vibration during cutting and to reduce the weight of the structure.

Korea Patent Publication No. 10-2007-0012264

An object of the present invention to solve the above problems is to provide a structural response using 3D printing technology to reduce vibration occurring during cutting and to provide a lightweight structure, so that it can be applied to high-speed machining, cutting precision and stability And to provide a lightweight and vibration-removable tool holder capable of increasing productivity and a machine tool having the same.

The technical problem to be achieved by the present invention is not limited to the above-mentioned technical problem, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

Configuration of the present invention for achieving the above object, the tool fixing portion to which the tool is coupled; a spindle coupling unit connected to the tool fixing unit and coupled to a spindle; and a lightweight vibration damping part provided by being laminated with metal between the tool fixing part and the spindle coupling part, wherein the lightweight vibration damping part includes a plurality of first metal layers stacked and spaced apart from each other; and a second metal layer including a plurality of support bars connecting the plurality of first metal layers, wherein the lightweight vibration damping part is formed by 3D printing.

In an embodiment of the present invention, the plurality of support bars are formed upright between the plurality of first metal layers to connect the plurality of first metal layers, but have different numbers in one or more of the plurality of first metal layers. can be placed.

In an embodiment of the present invention, the plurality of support bars may include at least one of a rectangular cross section and a circular cross section.

In an embodiment of the present invention, a plurality of rubber layers disposed between the tool fixing unit and the lightweight vibration damping unit; and a ball bearing disposed between the plurality of rubber layers.

In an embodiment of the present invention, the tool fixing unit may include an oggetic structure.

In an embodiment of the present invention, the lightweight vibration damping unit may have a negative Poisson's ratio that contracts when compressed and expands when stretched.

Another configuration of the present invention, the tool fixing portion to which the tool is coupled; a spindle coupling unit connected to the tool fixing unit and coupled to a spindle; and a lightweight vibration damping part provided by being laminated with metal between the tool fixing part and the spindle coupling part. and a balanced metal layer coupled to at least one of an upper part and a lower part of the inclined metal layer, wherein the inclined metal layer and the balanced metal layer are alternately disposed, and the lightweight vibration damping part is formed by 3D printing.

In another embodiment of the present invention, the inclined metal layer includes a plurality of inclined bars disposed radially inclined at a central portion, and the balanced metal layer includes an edge bar interconnecting outer sides of the inclined bars, and An upper and lower connection bar vertically interconnecting the central portion and the balanced metal layers may be further included.

In another embodiment of the present invention, the lightweight vibration damping unit may be formed of a laminated organic structure.

In another embodiment of the present invention, the lightweight vibration damping unit may have a negative Poisson's ratio that contracts when compressed and expands when stretched.

In another embodiment of the present invention, the lightweight vibration damping unit may further include a plurality of vibration damping layers having different damping coefficients.

In another embodiment of the present invention, the plurality of vibration damping layer portion, the first vibration damping layer adjacent to the tool fixing portion; and a second vibration damping layer adjacent to the spindle coupling part, and a damping coefficient of the first vibration damping layer part may be greater than that of the second vibration damping layer part.

In another embodiment of the present invention, at least one of the plurality of vibration damping layer parts may include a non-metal layer.

In another embodiment of the present invention, the non-metal layer may include carbon nanotubes.

Another aspect of the present invention provides a machine tool including the tool holder.

The effect of the present invention according to the configuration as described above is applicable to high-speed machining by presenting a structural response using 3D printing technology to reduce vibration and lighten the structure that occurs during cutting, cutting precision, stability and productivity It is possible to provide a tool holder capable of reducing weight and damping vibration and a machine tool having the same.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a front view of tool installation of a tool holder capable of lightening and damping according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line I-I of FIG. 1 .
FIG. 3 is a II-II sectional view of FIG. 1 .
4 is a front view of tool installation of a tool holder capable of reducing weight and damping according to another embodiment of the present invention.
FIG. 5 is an organic structure applied to FIG. 4 .
FIG. 6 is a view in which a plurality of vibration damping layers are added to FIG. 4 .

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms, and therefore is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this is not only "directly connected", but also "indirectly connected" with another member in between. "Including cases where In addition, when a part "includes" a certain component, it means that it may further include other components without excluding other components unless otherwise stated.

Terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "include" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a front view of tool installation of a tool holder capable of reducing weight and damping dust according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line I-I of FIG. 1, and FIG. 3 is a cross-sectional view taken along line II-II of FIG.

1 to 3, a tool holder 100 capable of reducing weight and damping according to an embodiment of the present invention is connected to a tool fixing part 101 to which a tool 10 is coupled and a tool fixing part 101 And, it includes a spindle coupling portion 105 coupled to the spindle, and a lightweight vibration damping portion 110 provided by metal laminating between the tool fixing portion 101 and the spindle coupling portion 105.

The lightweight vibration damping unit 110 includes a plurality of first metal layers 111 stacked and spaced apart from each other, and a second metal layer including a plurality of support bars 116 connecting the plurality of first metal layers 111 ( 115).

The lightweight vibration damping unit 110 is formed by 3D printing and has a structure in which a second metal layer 115 for disposing support bars 116 is disposed between a plurality of first metal layers 111, thereby having a structure in which a plurality of first metal layers 111 are disposed. Vibration and shock transmission between the metal layers 111 may be damped by the plurality of support bars 116 constituting the second metal layer 115 .

The plurality of support bars 116 are formed upright between the plurality of first metal layers 111 to connect the plurality of first metal layers 111, but have different numbers in one or more of the plurality of first metal layers 111. can be placed.

For example, the plurality of support bars 116 disposed on the upper part of the lightweight vibration damping unit 110 may be composed of four, and the plurality of support bars 116 disposed above and below them may be provided with five. However, it is not limited thereto, and depending on the length and diameter of the lightweight vibration damping unit 110, fewer parts may be disposed that cause more vibration than other parts.

As shown, the plurality of support bars 116 may have a rectangular cross section, but are not limited thereto and may be provided with a circular cross section.

The arrangement structure and cross-sectional shape of the plurality of support bars 116 affect vibration damping, and are not necessarily limited to rectangular or circular cross sections, and practical axial and transverse vibration analysis of the lightweight vibration damping unit 110 can be appropriately selected according to

Meanwhile, a rubber layer 121 and a ball bearing 122 may be disposed under the lightweight vibration damping unit 110 .

That is, a plurality of rubber layers 121 may be disposed between the tool fixing part 101 and the lightweight vibration damping part 110 , and a ball bearing 122 may be disposed between the plurality of rubber layers 121 .

The outer surface of the lightweight vibration damping unit 110 in which the plurality of rubber layers 121 and the ball bearings 122 are disposed may be wrapped with metal or non-metal. In this case, the non-metal graphene-carbon nanotube structure may be used.

The plurality of rubber layers 121 block vibration or impact transmitted from the tool fixing part 101 to the upper part of the lightweight vibration damping part 110, and the ball bearing 122 is a microstructure of the plurality of rubber layers 121. It absorbs transverse vibration by allowing relative motion.

The rubber layer 121 may be replaced with a structural plate made of a graphene-carbon nanotube structure.

The structural plate of the graphene-carbon nanotube structure generates additional bending and shear stress in the structure where vibration occurs, and at the same time quickly transfers the heat generated in the structure to the outside to further improve the damping efficiency. do. Moreover, since the graphene-carbon nanotube structure forms a three-dimensional structure, it can provide more improved spring and damping.

On the other hand, the lightweight vibration damping unit 110 may include an organic structure.

As will be described later, such an organic structure is a structure in which bars capable of absorbing vibration are three-dimensionally connected, and can provide a negative Poisson's ratio that contracts when compressed and expands when stretched. This negative Poisson's ratio is used to increase the performance of vibration damping by providing elastic deformation opposite to the general structure.

4 is a front view of tool installation of a tool holder capable of reducing weight and damping vibration according to another embodiment of the present invention, FIG. 5 is an organic structure applied to FIG. 4, and FIG. 6 is a plurality of vibration damping layers added to FIG. it is a drawing

4 and 5, a tool holder 200 capable of reducing weight and damping according to another embodiment of the present invention is connected to a tool fixing part 201 to which a tool is coupled, a tool fixing part 201, and a spindle. It includes a spindle coupling portion 205 coupled to, and a lightweight vibration damping portion 210 provided by metal laminating between the tool fixing portion 201 and the spindle coupling portion 205.

The lightweight vibration damping unit 210 is formed by 3D printing, and includes an inclined metal layer 211 inclined outward from the central portion and a balanced metal layer 215 coupled to at least one of upper and lower portions of the inclined metal layer 211. Including, the inclined metal layer 211 and the balanced metal layer 215 are alternately disposed.

The inclined metal layer 211 includes a plurality of inclined bars 212 radially inclined at the center, and the balanced metal layer 215 includes an edge bar 216 interconnecting the outside of the inclined bars 212.

The inclined metal layers 211 and the balanced metal layers 215 are vertically interconnected by upper and lower connecting bars 217 .

For example, the structure of the lightweight vibration damping unit 210 is an organic structure that is laminated and connected, and is a structure that can sufficiently absorb impact energy while making local reinforcement by increasing the density of the compression region.

The lightweight vibration damping unit 210 has an organic laminated structure, and may have a negative Poisson's ratio that contracts when compressed and expands when stretched.

In the case of a general material with a positive Poisson's ratio, the material expands in the direction perpendicular to the load in the contraction state, and the opposite phenomenon is observed in the tension state.

On the other hand, a negative Poisson's ratio structure is a structure in which the material shrinks in the direction perpendicular to the load when placed in a contraction condition due to the characteristics of the structure shape, not the physical properties of the material, and expands in a tension condition. say Since this negative Poisson's ratio structure was proposed by Lakes (1987), it has been developed in various forms.

The Oggetic structure not only improves overall stiffness by increasing the amount of strain energy absorbed per unit mass, but also increases the area of the connection line to relieve stress concentration, which can be expected to increase durability.

Although not shown, the plurality of slanted bars 212, the rim bar 216, and the upper and lower connecting bars 217 may be bent in a “(”, “)” or “S” shape to increase elasticity.

The Oggetic structure not only improves the overall stiffness by increasing the amount of strain energy absorbed per unit mass, but also increases the area of the connection line to relieve stress concentration, thereby forming a three-dimensional structure. Further improved spring and damping can be provided.

Meanwhile, referring to FIG. 6 , the lightweight vibration damping unit 210 may further include a plurality of vibration damping layers 221 and 222 having different damping coefficients.

The plurality of vibration damping layer parts 221 and 222 may include a first vibration damping layer 221 adjacent to the tool fixing part 201 and a second vibration damping layer 222 adjacent to the spindle coupling part 205. can

The first vibration damping layer 221 may have a higher damping coefficient than the second vibration damping layer 222 .

The first vibration damping layer 221 blocks vibration transmitted from the tool fixing part 201 to the lightweight vibration damping part 210, and the second vibration damping layer 222 blocks vibration from the lightweight vibration damping part 210. Vibration toward the spindle coupling part 205 or vice versa is blocked.

At least one of the plurality of vibration damping layer parts 221 and 222 may include a non-metal layer.

For example, the first vibration damping layer 221 and the second vibration damping layer 222 may be provided with a plurality of love layers and ball bearings as described above, but are not limited thereto, and the second vibration damping layer 222 ball bearings can be omitted.

Meanwhile, the first vibration damping layer 221 and the second vibration damping layer 222 may include carbon nanotubes.

Since the first vibration damping layer 221 and the second vibration damping layer 222 are provided as a graphene-carbon nanotube structure, additional bending and shear stresses are generated in the structure in which vibration occurs, and at the same time in the structure. It is possible to further improve the attenuation efficiency by quickly transferring the generated heat to the outside. Moreover, since the graphene-carbon nanotube structure forms a three-dimensional structure, it can provide more improved spring and damping.

The graphene-carbon nanotube structure may be provided as a composition mixed with polyurethane and coated or adhered to a substrate in a viscoelastic manner.

Meanwhile, according to another embodiment of the present invention, a machine tool including the tool holders 100 and 200 may be provided.

The above description of the present invention is for illustrative purposes, and those skilled in the art can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the scope of the present invention.

100, 200: tool holder 101, 201: tool fixing part
105, 205: spindle coupling part 110, 210: lightweight vibration damping part
111: first metal layer 115: second metal layer
116: support bar 121: rubber layer
122: ball bearing
211: inclined metal layer 212: inclined bar
215 flat metal layer 216 rim bar
217: upper and lower connecting bars 221: first vibration damping layer
222: second vibration damping layer

Claims (15)

a tool fixing unit to which a tool is coupled;
a spindle coupling unit connected to the tool fixing unit and coupled to a spindle; and
It includes a lightweight vibration damping part provided by being metal laminated between the tool fixing part and the spindle coupling part,
The lightweight vibration damping unit,
a plurality of first metal layers stacked and spaced apart from each other; and
A second metal layer including a plurality of support bars connecting between the plurality of first metal layers;
The lightweight vibration damping unit is formed by 3D printing,
The plurality of support bars,
It is formed upright between the plurality of first metal layers to connect the plurality of first metal layers,
A tool holder capable of reducing weight and damping, characterized in that different numbers are arranged in one or more of the plurality of first metal layers.
delete The method of claim 1,
The plurality of support bars is a lightweight and damping tool holder, characterized in that it comprises at least one of a square and circular cross section.
The method of claim 1,
a plurality of rubber layers disposed between the tool fixing unit and the lightweight vibration damping unit; and
A lightweight and damping tool holder, characterized in that it further comprises a ball bearing disposed between the plurality of rubber layers.
The method of claim 1,
The tool holder is lightweight and dampable tool holder, characterized in that it comprises an oggetic structure.
The method of claim 1,
The lightweight vibration damping part has a negative Poisson's ratio that contracts during compression and expands during tension.
a tool fixing unit to which a tool is coupled;
a spindle coupling unit connected to the tool fixing unit and coupled to a spindle; and
It includes a lightweight vibration damping part provided by being metal laminated between the tool fixing part and the spindle coupling part,
The lightweight vibration damping unit,
an inclined metal layer inclined outward from the central portion;
a balanced metal layer coupled to at least one of an upper part and a lower part of the inclined metal layer; and
A plurality of vibration damping layers having different damping coefficients;
The inclined metal layer and the balanced metal layer are alternately disposed,
The lightweight vibration damping unit is a lightweight and damping tool holder, characterized in that formed by 3D printing.
The method of claim 7,
The inclined metal layer includes a plurality of inclined bars radially inclined from a central portion,
The balanced metal layer includes an edge bar interconnecting outer sides of the inclined bars,
A tool holder capable of reducing weight and damping damping, characterized in that it further comprises an upper and lower connecting bar vertically interconnecting the central portion of the inclined metal layers and the balanced metal layers.
The method of claim 8,
The lightweight vibration damping unit is a lightweight and damping tool holder, characterized in that formed of an organic structure connected to the stack.
The method of claim 7,
The lightweight vibration damping part has a negative Poisson's ratio that contracts during compression and expands during tension.
delete The method of claim 7,
The plurality of vibration damping layer parts,
a first vibration damping layer adjacent to the tool fixture; and
A second vibration damping layer adjacent to the spindle coupling portion,
A lightweight and damping tool holder, characterized in that the damping coefficient of the first vibration damping layer is greater than that of the second vibration damping layer.
The method of claim 7,
A lightweight and damping tool holder, characterized in that at least one of the plurality of vibration damping layer comprises a non-metallic layer.
The method of claim 13,
The non-metal layer is a lightweight and damping tool holder, characterized in that it comprises carbon nanotubes.
A machine tool comprising the tool holder according to any one of claims 1, 3 to 10 and 12 to 14.

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