JP2016083712A - Vibration damping material for machine tool, structure and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration damping material for a machine tool high in mechanical strength and rigidity and improved in processing accuracy by suppressing chattering vibration, and to provide a structure and a manufacturing method thereof.SOLUTION: The vibration damping material 2 for the machine tool formed by filling the gaps of tightly packed aggregates 20, 21, and 22 with binding materials 23 is characterized in that the aggregates 20, 21, and 22 include a coarse aggregate 20 of 50 to 70 vol%, an intermediate aggregate 21 of 20 to 28 vol% having a particle diameter Rset to 1/7 or less for the particle diameter Rof the coarse aggregate 20, and a fine aggregate 22 of 5 to 15 vol% having a particle diameter Rset to 1/49 or less for the particle diameter Rof the coarse aggregate 20. The vibration damping material for the machine tool is also characterized in that at least one of the coarse aggregate 20, the intermediate aggregate 21, and the fine aggregate 22 is made of magnesium, and the others are made of sintered alumina.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a machine tool vibration damping material, a structure, and a manufacturing method thereof, and more particularly, a machine tool vibration damping material formed by filling a gap in a densely filled aggregate with a binder, The present invention relates to a structure and a manufacturing method thereof.

  In a machine tool such as a lathe for cutting by rotating a workpiece or a milling machine for cutting by rotating a tool, unnecessary vibration called chatter vibration is generated during cutting. Chatter vibration not only reduces quality due to deterioration of the finish surface properties, but also causes abnormal wear of tools and damage to the machine structure. Actions to avoid are required.

  In general, “chatter vibration” is roughly classified into forced chatter due to forced vibration and self-excited chatter due to self-excited vibration. Forced chatter is vibration that occurs when machining is performed while machine tools, tools, and workpieces vibrate. Force disturbance type forced chatter, in which the machining itself, such as the machining method and chip generation, is the source of vibration. And displacement disturbance type chatter in which vibrations from the outside such as the main shaft vibration of the machine tool and the vibration of a nearby machine become a vibration source. On the other hand, self-excited chatter is vibration that occurs when the vibration generated by fluctuations in cutting resistance during the cutting process is not converged. It is classified as friction type chatter.

  Conventionally, as a vibration damping material for suppressing chatter vibration generated in the above-described machine tool, for example, as disclosed in Patent Document 1, strong ceramics, engineering plastic having a lower density than iron, and lightweight aggregate A resin concrete structure has been proposed which is formed by filling a binder made of a thermosetting resin together with an aggregate such as the above. According to such a vibration damping material, vibration damping characteristics can be improved, and thus the above-described chatter vibration can be suppressed by using it as a tool post or a bed of a machine tool instead of a conventional steel material.

  However, the vibration damping material of a machine tool disclosed in Patent Document 1 described above has a problem that mechanical strength and rigidity are inferior to steel materials and the like, as is known as a defect of resin concrete. Further, in Patent Document 1, it is disclosed that it is preferable to use a known substance having strength and rigidity as an aggregate to ensure mechanical strength and rigidity. Where vibration damping characteristics and mechanical properties as a material (composite) depend on the selection and filling state of aggregates, in combination with other aggregates to maintain and improve vibration damping characteristics along with mechanical characteristics, The blending ratio (volume ratio) that affects the filling state was not taken into consideration, and there was enough room for improvement.

JP 7-68403 A

  Therefore, the present invention relates to a vibration damping material, a structure, and a manufacturing method thereof for machine tools, which solves the above-described conventional problems, and is excellent in mechanical strength and rigidity, suppressing chatter vibration and improving machining accuracy. Another object of the present invention is to provide a vibration damping material and structure for a machine tool, and a method for manufacturing the same.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, in Claim 1, in the vibration damping material of a machine tool that is formed by filling a gap in a densely filled aggregate with a binder, the aggregate is 50 to 70 vol% of coarse aggregate, 20 to 28 vol% of the medium aggregate whose particle size is 1/7 or less of the particle size of the coarse aggregate, and 5 to 5 of fine aggregate whose particle size is 1/49 or less of the particle size of the coarse aggregate 15 vol%, and at least one of the coarse aggregate, medium aggregate, and fine aggregate is made of magnesium, and the other is made of calcined alumina.

  In the present invention, the coarse aggregate is made of calcined alumina.

  In the present invention, the coarse aggregate and the fine aggregate are made of calcined alumina.

  According to a fourth aspect of the present invention, there is provided a machine tool structure using the vibration damping material according to any one of the first to third aspects.

  According to a fifth aspect of the present invention, there is provided a metal member which is formed in a shape connectable to a predetermined machine tool and is provided with an anchor bolt for preventing peeling, and the vibration damping material is connected to the metal via the anchor bolt. It is molded integrally with the member.

  According to a sixth aspect of the present invention, there is provided a method of manufacturing a vibration damping material for a machine tool that is formed by filling a gap in a densely filled aggregate with a binder, and 50 to 70 vol of coarse aggregate in a predetermined mold. 20% to 28% by volume of the medium aggregate whose particle size is 1/7 or less of the particle size of the coarse aggregate, and the fine aggregate whose particle size is 1/49 or less of the particle size of the coarse aggregate 5 to 15 vol%, and at least one of the coarse aggregate, medium aggregate, and fine aggregate is made of magnesium, and the other is made of sintered alumina, and a binder. It comprises a stirring and filling step for stirring and filling, a vibration step for vibrating the mold, and a pressure curing step for curing the binder in a state where the mold is pressurized.

  According to a seventh aspect of the present invention, there is provided a method of manufacturing a structure using a vibration damping material of a machine tool that is formed by filling a gap in a densely filled aggregate with a binder, and a shape that can be connected to a predetermined machine tool. The coarse aggregate is 50 to 70 vol% and the particle diameter is 1 of the particle diameter of the coarse aggregate in a mold in which a metal member provided with an anchor bolt for preventing peeling is installed. / 7-7 or less of the medium aggregate containing 20 to 28 vol%, and the fine aggregate having a particle size of 1/49 or less of the particle size of the coarse aggregate is 5 to 15 vol%. At least one of aggregate, medium aggregate, and fine aggregate is made of magnesium, the other is made of calcined alumina, and an agitation and filling step of agitation and filling the binder, and the mold is vibrated. Exciting step and curing the binder in a state where the mold is pressed And and cured step is made a.

  As an effect of the present invention, it is excellent in mechanical strength and rigidity, can suppress chatter vibration, and improve machining accuracy.

It is a perspective view of the tool post using the vibration damping material which concerns on one Example of this invention. It is the figure which showed typically the filling state of the vibration damping material. It is a flowchart which shows the manufacturing method of the tool post using a vibration damping material. It is the figure which showed the result of having measured the density of the vibration damping material. It is the figure which showed the result of having measured the Young's modulus of the vibration damping material. It is the figure which showed the result of having measured the damping ratio of the vibration damping material. It is the figure which showed the result of having measured the surface roughness after the cutting process by a round chip. It is the figure which showed the result of having measured the chatter vibration incidence after the cutting process by a round chip. It is the figure which showed the result of having measured the surface roughness after the cutting process by the shaving tip. It is a photograph of the processed surface after cutting with a shaving tip. It is the figure which showed the result of having measured the vibration amplitude at the time of the cutting process by a shaving tip.

  Next, modes for carrying out the invention will be described.

  In the following embodiments, as an example of a structure of a machine tool such as a lathe for rotating a workpiece to cut and a milling machine for cutting by rotating a tool, the tool post 1 using the vibration damping material 2 of the present embodiment is used. Is described. However, as will be described later, the structure of the machine tool using the vibration damping material 2 is not limited to the tool post 1.

<Tool post>
As shown in FIG. 1, the tool post 1 is attached to a predetermined machine tool and is configured to be able to fix a tool holder (not shown). Specifically, anchor bolts 31 and 41 for preventing peeling are provided. The metal members 3 and 4 are provided, and the vibration damping material 2 is formed integrally with the metal members 3 and 4 via the anchor bolts 31 and 41. The vibration damping material 2 is formed in a substantially rectangular parallelepiped shape, and a steel metal member 3 formed in a substantially U shape is disposed on the upper edge (upward direction in FIG. 1) of the vibration damping material 2 to vibrate. A pair of steel metal members 4, 4 are disposed at opposite edges of the damping material 2 (downward in FIG. 1).

  The metal member 3 is configured as a fixing member for a tool holder (not shown), and the tool holder is mounted sideways in a mounting groove 30 a that is recessed along the longitudinal direction of the metal body 30. It is fixed by fasteners such as bolts (not shown) through the drilled bolt holes 30b, 30b. Further, the metal member 3 is provided with anchor bolts 31, 31... Projecting from a side surface of the metal body 30 and joined to the vibration damping material 2, and the anchor bolts 31, 31. By being embedded in 2, the vibration damping material 2 and the metal member 3 are configured to be prevented from peeling off.

  The metal member 4 is configured as an attachment member to a carriage (not shown) of a machine tool (not shown), and in a state where the tool post 1 is installed, bolt holes 40a, 40a,. Is attached to the machine tool by a fastener such as a bolt (not shown). Similarly, the metal member 4 is also provided with anchor bolts 41, 41... Projecting from one side of the metal body 40 and on the joint surface with the vibration damping material 2, and the anchor bolts 41, 41. By being embedded in the damping material 2, the vibration damping material 2 and the metal member 4 are configured to be prevented from peeling off.

<Vibration damping material>
The vibration damping material 2 is configured as a composite material (composite) formed by filling a gap between densely filled aggregates 20, 21, and 22 with a binder 23, and the aggregates 20, 21, and 22 are rough. Aggregate 20 is 50 to 70 vol%, and particle size R ₂ is 20 to 28 vol% of medium aggregate 21 whose particle size R ₂ is 1/7 or less of particle diameter R ₁ of coarse aggregate 20 (R ₁ > R ₂ ). The fine aggregate 22 having a diameter R ₃ of 1/49 or less (R ₁ > R ₂ > R ₃ ) of the particle diameter R ₁ of the coarse aggregate 20 is contained in an amount of 5 to 15 vol%.

The vibration damping material 2 is filled so that the aggregates 20, 21, 22 and the bonding material 23 are in the most filled state, and the volume ratio of each component is described as follows. As shown in FIG. 2, first, in a state where only coarse aggregate 20 having a particle diameter R ₁ in a predetermined container 10 is filled, about 60 vol% of the container 10 is filled with coarse aggregate 20 ( (See FIG. 2 (a)). The filling form at this time is orthorhombic filling. At this stage, the space of the coarse aggregate 20 in the container 10 is 40 (= 100−60) vol%.

Next, in a state where the medium aggregate 21 is filled between the coarse aggregates 20, the medium aggregate 21 having a particle diameter R _{2 that} is 1/7 or less of the particle diameter R ₁ of the coarse aggregate 20 is between the coarse aggregates 20. It passes through the gap and fills approximately 24 (= 40 × 0.6) vol% of the space (see FIG. 2B). At this time, the filling form of the medium aggregate 21 is also orthorhombic filling. At this stage, the space of the coarse aggregate 20 and the medium aggregate 21 in the container 10 is 16 (= 100-60-24) vol%.

Then, in a state where the fine aggregate 22 between coarse aggregate 20 and the medium aggregate 21 is filled, fine aggregate 22 of 1/49 or less the particle size _{R 1} particle size _{R 3} is coarse aggregate 20 is rough It passes through the gap between the aggregate 20 and the middle aggregate 21 and is filled to approximately 10 (= 16 × 0.6) vol% of the space (see FIG. 2C). The filling form of the fine aggregate 22 is also orthorhombic filling. Finally, the binder 23 is filled in the space 6 (= 100-60-24-10) vol% between the coarse aggregate 20, the medium aggregate 21, and the fine aggregate 22 (FIG. 2 (d). )reference).

  Thus, the theoretical values of the volume ratios of the constituent components in the state where the aggregates 20, 21, 22 and the binder 23 are densely filled are 60 vol% for the coarse aggregate 20 and 24 vol% for the middle aggregate 21. The fine aggregate 22 is 10 vol%, and the binder 23 is 6 vol%. However, in actual molding, since the most filled state changes under the influence of the shape and surface state of the aggregates 20, 21, and 22, the viscosity of the binder 23, and the like, the vibration damping material 2 is a coarse aggregate. It is preferable that 20 is 50 to 70 vol%, the middle aggregate 21 is 20 to 28 vol%, and the fine aggregate 22 is 5 to 15 vol%. The blending amount of the binder 23 is appropriately adjusted so that the surplus space is filled in accordance with the blending amounts of the aggregates 20, 21, and 22.

  As the type of aggregate, at least one of coarse aggregate 20, medium aggregate 21, and fine aggregate 22 is made of magnesium and the others are made of calcined alumina. Preferably, coarse aggregate 20 is calcined alumina. More preferably, the coarse aggregate 20 and the fine aggregate 22 are made of calcined alumina. In the vibration damping material 2, magnesium is used together with calcined alumina as a constituent component of the aggregate, so that desired vibration damping characteristics are achieved with magnesium, and desired mechanical strength and rigidity are achieved with calcined alumina.

  Firing alumina and magnesium are materials that are relatively light and excellent in strength and rigidity among practical metals, and in particular, magnesium has a vibration damping characteristic that has a greater damping ratio than fired alumina. Table 1 shows the mechanical characteristics (physical property data) of materials generally used as machine tool structures and the like, together with the calcined alumina and magnesium used in this example.

  As the type of the binder 23, a known thermosetting resin such as an epoxy resin or a phenol resin is used.

  As an example of the constituent components of the vibration damping material 2, for example, an aggregate containing a coarse aggregate 20 made of calcined alumina, a medium aggregate 21 made of magnesium, and a fine aggregate 22 made of calcined alumina in a predetermined volume ratio, respectively. And the binder 23 (epoxy resin or the like), the sintered alumina (coarse aggregate 20 / fine aggregate 22) functions as a structure having mechanical strength and rigidity, and magnesium (medium aggregate 21). ) Can be the vibration damping material 2 in which the functions of the vibration damping characteristics are balanced.

  Also, for example, an aggregate and a binder 23 (epoxy resin or the like) containing a coarse aggregate 20 made of calcined alumina, a medium aggregate 21 made of magnesium, and a fine aggregate 22 made of magnesium in a predetermined volume ratio, respectively. When configured, the vibration damping material 2 that exhibits superior vibration damping characteristics as compared with the above while maintaining predetermined mechanical strength and rigidity with magnesium (medium aggregate 21 and fine aggregate 22); can do.

  Further, for example, an aggregate and a binder 23 (epoxy resin or the like) containing a coarse aggregate 20 made of magnesium, a medium aggregate 21 made of baked alumina, and a fine aggregate 22 made of baked alumina in a predetermined volume ratio, respectively. However, the mechanical strength / rigidity can be suppressed, but the vibration damping material 2 that exhibits more excellent vibration damping characteristics can be obtained. In such a case, since mechanical strength and rigidity are limited, it is not suitable for use as a structure (for example, a spacer or a floor board) that requires mechanical strength and rigidity.

<Method of manufacturing the tool post>
As shown in FIG. 3, as a method of manufacturing the tool post 1 using the vibration damping material 2, it is formed in a shape connectable to a predetermined machine tool, and anchor bolts 31 and 41 for preventing peeling are provided. In a molding die (not shown) where the metal members 3 and 4 are installed, the coarse aggregate 20 is 50 to 70 vol%, the middle aggregate 21 is 20 to 28 vol%, and the fine aggregate 22 is 5 to 15 vol%. And at least one of the coarse aggregate 20, the medium aggregate 21, and the fine aggregate 22 is made of magnesium and the other is made of sintered alumina, and the binder 23 is stirred and filled. The stirring and filling step S100, the vibration step S101 for vibrating the mold, the pressure curing step S102 for curing the binder 23 in a state where the mold is pressurized, and the like are included.

  In the stirring and filling step S100, first, the metal members 3 and 4 constituting the tool post 1 are arranged at predetermined positions in the mold. The metal members 3 and 4 are preliminarily positioned so as to be in a relative position with respect to the vibration damping material 2. The mold is made of a material such as a wooden mold or a plaster mold, and the remaining space is filled with the aggregates 20, 21, 22 and the bonding material 23 in a state where the metal members 3 and 4 are arranged. The vibration damping material 2 having a predetermined shape, in which the metal members 3 and 4 are integrally formed, is obtained. Next, the aggregates 20, 21, 22 and the binder 23 are prepared so as to have a predetermined volume ratio, and after stirring in another place in advance, the aggregate is supplied and filled in the above-described mold.

  In the vibration process S101, the mold 20, in which the aggregates 20, 21, 22 and the binder 23 are stirred and filled is vibrated using a vibrator. In this way, the mold 20 is vibrated before the binder 23 hardens, thereby excluding the air contained in the aggregates 20, 21, 22 and the binder 23, and instantaneously the aggregates 20, 21, 22. It is possible to create a gap therebetween and fill the bonding material 23 therewith, and evenly fill the bonding material 23 to increase the packing density of the aggregates 20, 21, 22 and the bonding material 23 in the mold. it can.

  In the pressure curing step S102, the bonding material 23 is cured in a state in which prestress (preliminary load) is applied to the aggregates 20, 21, 22 and the bonding material 23 filled in the mold and is pressed. By curing the bonding material 23 in a pressurized state, the bonding material 23 (film) interposed between the coarse aggregates 20 can be thinned, and the mechanical strength of the vibration damping material 2 can be improved. In this way, the tool post 1 in which the vibration damping material 2 is integrally formed with the metal members 3 and 4 via the anchor bolts 31 and 41 is obtained.

  In addition, as a manufacturing method of the vibration attenuating material 2 or another structure (such as a spacer or a base plate) using the vibration attenuating material 2, in accordance with the manufacturing method of the tool post 1 described above, for example, in a mold What is necessary is just to shape | mold by filling the component of the vibration damping material 2 without installing another metal member or installing another metal member.

<Measurement of mechanical properties of vibration damping material>
Vibration damping material is formed using aggregate (coarse aggregate, medium aggregate, fine aggregate) and binder made of calcined alumina and magnesium, and mechanical properties of density, Young's modulus, and damping ratio (physical property data) ) Was measured.

  The vibration damping material used for the measurement was aggregate (coarse aggregate / medium aggregate / fine aggregate) composed of calcined alumina and magnesium shown in Table 2, coarse aggregate 60 vol%, and medium aggregate 24 vol%. The mixture was mixed so that the fine aggregate was 10 vol%, and the binder (epoxy resin) was 6 vol%, and the mixture was stirred and filled in a predetermined mold, and after pressurizing, each sample was molded by pressing and curing ( Example: Sample Nos. 1-3). Similarly, each sample for comparison was shape | molded using each material shown in Table 2 (comparative example: sample No. 4-15).

  Physical properties data of density, Young's modulus, and damping ratio were measured for each sample obtained, and the results are shown in Table 2. FIGS. 4 to 6 sequentially show the samples with the highest measured values of density, Young's modulus, and damping ratio (ten).

  Thus, in the case of using an aggregate containing a coarse aggregate made of calcined alumina, a medium aggregate made of magnesium, and a fine aggregate made of calcined alumina in a predetermined volume ratio (sample No. 3), Thus, a well-balanced vibration damping material excellent in mechanical characteristics and vibration damping characteristics can be obtained.

  In addition, when using an aggregate containing a coarse aggregate made of calcined alumina, a medium aggregate made of magnesium, and a fine aggregate made of magnesium in a predetermined volume ratio (sample No. 2), Compared with the case (sample No. 3), the vibration damping characteristics are excellent, and the aggregate contains a coarse aggregate made of magnesium, a medium aggregate made of calcined alumina, and a fine aggregate made of calcined alumina in a predetermined volume ratio. (Sample No. 1) can exhibit more excellent vibration damping characteristics, although mechanical strength and rigidity are suppressed compared to the above case (Sample No. 3 etc.). .

<Effectiveness evaluation 1 by actual cutting 1>
A tool post using a vibration-damping material was formed, and a semi-finished cutting with a round tip on a machine tool (NC lathe) was performed to evaluate the chatter vibration suppression effect. The round insert has a large nose radius, so good surface roughness is obtained, and the cutting edge strength is high, so it is used for medium-heavy cutting. However, as the cutting depth increases, the cutting width of the tool increases. The feature is that chatter vibration is likely to occur.

  The tool post used for the measurement is 60 vol% of coarse aggregate made of calcined alumina, 24 vol% of medium aggregate made of magnesium, and 10 vol% of fine aggregate made of calcined alumina as components of the vibration damping material. The material (epoxy resin) is blended so as to be 6 vol% (see sample No. 3 in Table 2), and the material is stirred and filled in a predetermined mold in which a metal member having a predetermined shape is previously set, and subjected to vibration. Thereafter, the sample was cured by pressure to obtain a sample in which the vibration damping material and the metal member were integrally formed (Example). For comparison, a conventional steel tool post was used (comparative example).

  The evaluation method uses a tool post (Example) using a vibration damping material and a conventional steel tool post (Comparative Example) to perform cutting by changing the cutting amount under the cutting conditions shown in Table 3 (5 Times), and the surface roughness and chatter vibration occurrence rate at that time were measured. The “chatter vibration occurrence rate” represents the ratio (%) of chatter vibration generated when cutting is performed. Judgment of occurrence of chatter vibration was evaluated by both auditory judgment during machining and mark judgment of the machined surface after machining.

  FIG. 7 shows the measurement result of the surface roughness at a predetermined depth of cut, and FIG. 8 shows the measurement result of the chatter vibration occurrence rate. In the tool post (Example) using the vibration damping material, the surface roughness is improved as compared with the conventional tool post (Comparative Example), and chatter vibration occurs when the cutting depth is 0.8 mm and 1.0 mm. Suppressed. In addition, in the tool post using the vibration damping material (Example), the suppression of chatter vibration is not seen when the depth of cut is 1.5 mm because the contact length between the tool and the workpiece is increased. Conceivable. In this way, by using the tool post (Example) using the vibration damping material, the occurrence of chatter vibration can be delayed in the semi-finished cutting with a round insert having a large cutting width of the tool. It was confirmed that normal machining was possible under cutting conditions.

<Effectiveness evaluation by actual cutting 2>
Next, a tool post using a vibration damping material was formed, and finish cutting of the outer circumference of the cylinder with a shaving tip in a machine tool (NC lathe) was performed to compare the surface roughness of the processed surface and evaluate the effect. The shaving tip has a feature that the nose radius is very large (300 mm in this experiment) and an extremely high-quality machining surface can be obtained, while the cutting width of the tool becomes large and chatter vibration is likely to occur. .

  In addition, since the shaving tip is mounted and processed with the cutting edge of the tool tilted at an angle (45 degrees) rather than parallel to the feed direction, instead of the nose radius, as shown in the following equation (1) The feature is that the radius of the workpiece is one of the determinants of the surface roughness. In equation (1), Ry is the maximum height (μm), Ra is the arithmetic average roughness (μm), F is the feed rate (mm / rev), r is the workpiece radius (mm), and θ is the cutting edge. And an angle (rad) formed by the feed direction.

  The tool post used for the measurement is 60 vol% of coarse aggregate made of calcined alumina, 24 vol% of medium aggregate made of magnesium, and 10 vol% of fine aggregate made of calcined alumina as components of the vibration damping material. The material (epoxy resin) is blended so as to be 6 vol% (see sample No. 3 in Table 2), and the material is stirred and filled in a predetermined mold in which a metal member having a predetermined shape is previously set, and subjected to vibration. Thereafter, the sample was cured by pressure to obtain a sample in which the vibration damping material and the metal member were integrally formed (Example). For comparison, a conventional steel tool post was used (comparative example).

  The evaluation method uses a tool post (Example) using a vibration damping material and a conventional steel tool post (Comparative Example) to change the feed rate under the cutting conditions shown in Table 4 and perform cutting (every five times). ) And the surface roughness at that time was measured.

  FIG. 9 shows the measurement results of the surface roughness at a predetermined feed rate, and FIG. 10 is a comparative photograph of the processed surfaces. The conventional steel tool post (comparative example) has a surface roughness Ra of about 2.4 μm, whereas the tool post using the vibration damping material (example) has a surface roughness Ra of 1.6 μm. It was confirmed that it can be made smaller than (finishing) and a high-quality surface roughness can be obtained.

  FIG. 11 shows the results of measuring the vibration amplitude during cutting (feed rate 0.05 mm / rev). In this example, an acceleration pickup is attached in the X direction at the end of the shank, and the vibration in the cutting direction considered to have the most influence on the surface roughness is measured. Note that the peak intensity is shown as a relative displacement obtained by subtracting a vibration that is simply applied without cutting from the vibration during shaving. This result shows that the turret (Example) using the vibration damping material has a smaller peak intensity in the vicinity of 20 to 30 Hz, and this difference affects the measurement result of the surface roughness of the machined surface. Is shown.

As described above, the vibration damping material 2 according to the present embodiment is the bone damping material 2 of a machine tool that is formed by filling the gaps of the aggregates 20, 21, and 22 that are densely filled with the binder 23. material 20, 21, 22, and 50 to 70 vol-% of coarse aggregate 20, and 20～28Vol% of Chukotsu material 21 is the particle diameter _{R 2} is less 1/7 of the particle diameter _{R 1} of the coarse aggregate 20 , becomes the particle size _{R 3} is contained, and 5～15Vol% fine aggregate 22 is 1/49 or less of a particle diameter _{R 1} of the coarse aggregate 20, coarse aggregate 20, the medium aggregate 21 and, Since at least one of the fine aggregates 22 is made of magnesium and the other is made of calcined alumina, the mechanical strength and rigidity are excellent, and chatter vibration can be suppressed to improve processing accuracy.

  That is, according to the vibration damping material 2 of the present embodiment, the coarse aggregate 20, the medium aggregate 21, and the fine aggregate 22 contain calcined alumina and magnesium, and the coarse aggregate 20 and the medium bone having a predetermined particle diameter are included. By setting it as the material 21 and the fine aggregate 22, it can be set as the composite material (composite) with which the aggregate was filled most. Therefore, by recruiting magnesium together with calcined alumina as a component of the aggregate, the desired vibration damping characteristics are achieved with magnesium, and the desired mechanical strength and rigidity are achieved with calcined alumina. The vibration damping characteristics can be enhanced, and the vibration damping performance of the structural material (tool post 1) using the vibration damping material 2 is suppressed, thereby suppressing chatter vibration and high quality and high addition due to improved machining accuracy. Value processing becomes possible.

  The vibration damping material 2, the structure using the vibration damping material 2 and the manufacturing method thereof are not limited to the above-described embodiments, and various modifications can be made without departing from the object of the present invention.

  That is, in the above-described embodiment, the case where the tool post 1 is configured as a structure using the vibration damping material 2 has been described. However, the structure is not limited to this, and the mechanical characteristics of the vibration damping material 2 are determined. For example, you may make it comprise as a spacer or a floor board using the vibration damping material 2.

  Moreover, in the manufacturing method of the vibration damping material 2 and the tool rest 1 according to the above-described embodiment, when the constituent material of the vibration damping material 2 is filled in the mold in the stirring and filling step (see FIG. 3), stirring is separately performed in advance. However, the filling method into the mold is not limited to this. For example, the coarse aggregate 20 → the medium aggregate 21 → the coarse aggregate 22 → the binder in a state where the mold is vibrated. 23 may be filled in order. Alternatively, the mold may be decompressed with a vacuum pump or the like after filling with the binder 23.

DESCRIPTION OF SYMBOLS 1 Tool post 2 Vibration damping material 3 Metal member 4 Metal member 20 Coarse aggregate 21 Medium aggregate 22 Fine aggregate 23 Binding material 30 Metal main body 31 Anchor bolt 40 Metal main body 41 Anchor bolt

Claims (7)

In the vibration damping material of a machine tool that is molded by filling a gap in the densely filled aggregate with a binder,
The aggregate is
Coarse aggregate 50-70 vol%,
20-28 vol% medium aggregate whose particle size is 1/7 or less of the particle size of the coarse aggregate,
Fine aggregate having a particle size of 1/49 or less of the particle size of the coarse aggregate is 5 to 15 vol%,
Containing
A vibration damping material for a machine tool, wherein at least one of the coarse aggregate, the medium aggregate, and the fine aggregate is made of magnesium and the other is made of calcined alumina.   The vibration damping material for a machine tool according to claim 1, wherein the coarse aggregate is made of calcined alumina.   The vibration damping material for a machine tool according to claim 1, wherein the coarse aggregate and the fine aggregate are made of calcined alumina.   A machine tool structure using the vibration damping material according to claim 1. It is formed in a shape that can be connected to a predetermined machine tool, and a metal member is provided with an anchor bolt for preventing peeling,
The machine tool structure according to claim 4, wherein the vibration damping material is formed integrally with the metal member via an anchor bolt. In a manufacturing method of a vibration damping material for a machine tool that is formed by filling a gap in a densely filled aggregate with a binder,
In a predetermined mold, the coarse aggregate is 50 to 70 vol%, the medium aggregate whose particle diameter is 1/7 or less of the particle diameter of the coarse aggregate is 20 to 28 vol%, and the particle diameter is the coarse bone. 5-15 vol% fine aggregate having a particle size of 1/49 or less of the particle size, and at least one of the coarse aggregate, medium aggregate, and fine aggregate is made of magnesium, A stirring and filling step of stirring and filling an aggregate made of calcined alumina and a binder;
An oscillating step of oscillating the mold;
A pressure curing step of curing the binder in a state where the mold is pressurized;
A method of manufacturing a vibration damping material for a machine tool comprising: In a method of manufacturing a structure using a vibration damping material of a machine tool that is molded by filling a gap in a densely filled aggregate with a binder,
The shape of the coarse aggregate is 50 to 70 vol% and the particle size is formed in a mold in which a metal member is provided with an anchor bolt for preventing peeling while being formed into a shape connectable to a predetermined machine tool. 20-28 vol% of medium aggregate that is 1/7 or less of the particle size of the coarse aggregate, and 5-15 vol% of fine aggregate that has a particle size of 1/49 or less of the particle size of the coarse aggregate Agitation and filling step in which at least one of the coarse aggregate, the medium aggregate, and the fine aggregate is made of magnesium and the other is made of calcined alumina and the binder is stirred and filled. When,
An oscillating step of oscillating the mold;
A pressure curing step of curing the binder in a state where the mold is pressurized;
A method for manufacturing a structure of a machine tool comprising: