JPS63278706A - Cutting tool - Google Patents

Abstract

PURPOSE:To facilitate combination and removal of a cutting edge part and to absorb vibration exerted on a cutting edge, by a method wherein a damping bond layer formed by an epoxy amide series adhesive consisting mainly of epoxy is formed between a base part and the cutting edge part to bond them together. CONSTITUTION:A mounting recessed part 3 is formed on the one side of the tip part of a base part 1, and a cutting edge part 2 is bonded thereto by means of a damping bond layer 4. A high speed steel, carbide, ceramic, etc. are used for a cutting edge part 2, a mechanical structural carbon steel, a carbon steel, a bearing steel, a high speed steel, and cast iron are used for the base part 1, and especially a vibration damping material consisting of 0.8-3.0% C, 1.0-3.0 Si, 25-40% Ni, 4.0-6.0% Co, 0-2.0% Mn, 0-1.0% S, 0-1.5% P, and remaining Fe is preferable. The damping bond layer 4 is epoxy polyamide series resin, and has tensile shear strength of 10-20 MPa, viscosity before curing (ordinary temperature) of 30-40 Pa.S, a volume coefficient of contraction during curing of approximate 2.4%, a lateral modulus of elasticity of 0.05-0.2 Gpa of a cured substance, a damping factor of 3-5MPa.S, a sprig constant of 70-130 GN/m of a bond layer part, and thickness of preferably 30-3mum.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cutting tool that is mounted on a machine tool and is fixed or rotated to cut a workpiece.

(Conventional technology) Lathes, machining centers, shaping machines, automatic lathes, shapers,
A cutting tool mounted on a tool rest or spindle of a machine tool such as a gear cutting machine or a drilling machine generally includes a base portion and a cutting edge portion fixed to the base portion. For this cutting edge portion, an optimal material is selected that corresponds to the physical and chemical properties of the workpiece and is excellent in terms of cutting accuracy and tool life.

In addition, the base part is made of a material with excellent dynamic characteristics of the tool, especially one with good vibration absorption, high one-frequency response, and little mechanical and thermal deformation, which satisfies the cutting accuracy. The material has been selected to have a long tool life.

The reality is that the so-called cutting edge and base parts are developed separately and independently, and the cutting edge is usually connected to the base part by silver brazing or the like.

(Problems to be Solved by the Invention) By the way, as mentioned above, brazing tools in which the cutting edge is joined to the base by silver brazing requires a high degree of skill and a long working time. However, when the cutting edge breaks or wears out, it takes a lot of time and skill to remove the brazing one by one. In addition, if silver brazing is simply done using a metal with good bonding properties and heat resistance, as in the case of tools, the physical and chemical properties of the material of the cutting edge and base will be damaged. It could become a problem.

This invention has been made in view of the above-mentioned circumstances, and its purpose is to easily connect the cutting edge to the base, and to prevent the cutting edge from breaking or wearing out. To provide a cutting tool whose cutting edge part can be easily removed from a base part and regenerated, and which can absorb vibrations applied to the cutting edge part during cutting.

(Means and effects for solving the problem) This invention has the following features:
A vibration-damping bonding layer made of an epoxy polyamide adhesive containing epoxy as a main component is interposed between the base portion and the cutting edge portion, and the vibration-damping bonding layer absorbs vibrations applied during machining. It's because I did it.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows a cutting tool that is mounted on a tool rest of a machine tool such as a lathe, and is composed of a base part 1 and a cutting edge part 2. That is, a mounting recess 3 is provided on one side of the tip of the base portion 1, and the cutting edge portion 2 is coupled to this mounting recess 3 by a vibration damping coupling layer 4, which will be described later. Therefore, the vibration-damping coupling layer 4 is interposed between the base portion 1 and the cutting edge portion 2, so that the two do not come into direct contact with each other.

The base part 1 and the cutting edge part 2 may be made of the same material,
In many cases, it is a combination of different materials.

The cutting edge portion 2 is made of high speed steel, carbide, ceramics,
Cermet, CBN, diamond, etc. are used. Further, the base portion 1 is generally made of carbon steel for mechanical structure.
Carbon steel, bearing steel, high speed steel.

Cast iron is used, especially FCIO1FC30,
Austenitic N1-Go alloy pig iron super invar alloy, FCD45, SK5, AQ-(5-55)%Z
n, AA standard 4032, A390. Ni alloy, CU
Gold alloy AQ Gold alloy vibration damping material can be arbitrarily selected and used. Also, according to experiments.

In particular, C; 0.8-3.0%, Si; 1.0-3
．． 0%, Ni; 25-40%, Co; 4.0-6.
0%, Mn; O~2.0%, S; O~1.
It is preferable to use an austenitic Ni-Go alloy cast iron consisting of 0%, P;
) X 10-@/℃, energy loss rate → 25-30
Particularly preferred are those having physical properties of %.

In addition, the damping bonding layer 4 described above can generally be made of a polymeric material having adhesive properties, but in particular an epoxy polyamide resin whose main component is epoxy, and which exhibits the following physical properties. is preferred.

Tensile shear strength τt → 10 to 20 MPa Viscosity before curing (
Room temperature) → 30-40 Pa-8 Volume shrinkage rate during curing → Approx. 2
．． 4% Transverse elastic modulus of cured product → G = 0.05 to 0.20 Pa Damping coefficient → C = 3 to 5 MPa-8 Spring constant of bonding layer → to = 70 to 130 ON/m And this vibration damping bonding layer The thickness of 4 is preferably 200 μm
1 to 1 μm, particularly preferably 30 to 3 μm
It is.

Next, the characteristics of the dissimilar material composite cutting tool configured as described above will be explained based on experimental results.

That is, 10 cutting tools (hereinafter referred to as Do-H) having the base part of the structure shown in Fig. 1 were manufactured using materials in the range shown below, and the actual workpiece (JIS S
US 304) was cut, and the maximum wear width Vc and average wear width VB of flank wear were determined.

[Material of base part]

Composition: C; 2.0-3.0%, Si; 2.0
~3.0%, Ni; 25~40%, Co; 5.0~
6.0% Physical properties: Coefficient of thermal expansion (0-20°C) → (2-3)XIO-”/'
C Energy loss rate → 27% Tensile shear strength → 10 to 20 kgf/no” Brinell hardness HB → 150 to 170 Longitudinal modulus of elasticity -+8000 to 9000 kgf/ff11
1" elongation → 8% or less Specific gravity → 7.8 [Material of vibration damping bonding layer] - Composition: Epoxy polyamide resin whose main component is epoxy Physical properties: Tensile shear strength t -410 to 15 MPa Viscosity before curing (room temperature) → 30 to 40 Pa-8 Volume shrinkage rate during curing → approximately 2.4% Transverse elastic modulus of cured product → G = 0.IGPa Damping coefficient - * C = 4.5M Pa-8 Bonding Spring constant of layer part → K = 100ON/m For comparison, the following cutting tool A (hereinafter referred to as DO-20H, bonding layer thickness 20 μm) and cutting tool B (hereinafter referred to as DO-100H, bonding layer thickness 10 μm) are used. and cutting tool Nor
Prepare a commercially available tool and cut the same workpiece (J I SS US 304) in the same way.
Flank wear was measured in the same manner. The cutting tool used at this time was a JIS P2O carbide tip, and the cutting edge shape was for JIS 33-2 type.

Cutting tool A (Do-20H): A cutting tool in which the above-mentioned base material is used and the cutting edge is bonded to the base with a vibration damping bonding layer of 20 μm.

Cutting tool B (DO-100H): A cutting tool is made with the same configuration as cutting tool A, but the thickness of the vibration damping coupling layer is 1
00μm and the same cutting edge as above (JIS P2O
) are combined.

Cutting tool N o r m a l: Commercially available product that uses JIS standard carbon steel as the base part (JIS33
-2 type), and the cutting edge (JIS P2O) is silver-brazed.

FIG. 2 shows the measurement results.

This cutting experiment was carried out using the cutting tools A, B and -Nor.
Maximum flank wear width V vs. cutting time for mal
c and the average flank wear width VB.

The Vc and VB of the cutting tool N o r m a l rapidly increase when the cutting time is between 10 m1n and 15 m1n, and when the cutting time reaches around 20 m1n, Do-20H, DO-
The amount of wear becomes larger from 100H, and the ranking does not change with the passage of time thereafter, with the cutting tool Normal showing the largest flank wear.

Additionally, depending on the type of adhesive used, there were concerns that the adhesive layer would repeatedly fatigue during cutting due to cutting resistance and cutting temperature, or that it would peel off or break due to thermal fatigue. The phenomenon never occurred. In addition, a fatigue test was conducted on the cutting tool, and the fatigue stress S and the number of repeated fractures N were investigated by applying the tensile shear road force that acts during cutting to the vibration damping composite layer, and an S-N curve was drawn. The results showed that there was no problem under the resistance and cutting temperature conditions.

Figure 3 shows the cutting tool Norma 1. Figure 4 shows DO-
The damping curves of free vibration of the 20H cutting tool are shown.

The evaluation characteristic value λ that determines the conditions in which the cutting tool is likely to cause chipping or chatter vibration due to cutting vibration is λ = k.
Until this invention, it has been shown through theoretical analysis that it can be determined by t(δ+δ2), but its characteristic value λ
is as follows.

However, δ is the damping ratio, which can be found from FIGS. 3 and 4. Further, kt is cutting rigidity.

Cutting tool Normal λ=5.84D○-20H
Cutting tool λ = 8.52DO-20H cutting tool is theoretically recognized to be about 50% less likely to cause chipping or chatter vibration. Also, cutting tool no.
If the damping ratio of rma l is averaged over a damping time of about 5 ms, it will be about 2.2%, whereas the Do-20H cutting tool will be about 3.2%. As is clear from this comparison, vibrations are attenuated about 50% faster in the different material composite cutting tool Do-20H than in the commercially available silver-brazed cutting tool.

FIG. 5 shows the finished surface roughness of the cut surface when the cutting time T=7 min. We investigated the progress until T = 30m1n, and found that Do-100H showed a relatively large change, and the value of the finished surface roughness sometimes increased and sometimes decreased at 1 o'clock, but the value was 5μ! 11-12 μm
It was a change in range. The cutting tool Normal or Do-20H has a variation in the range of 8 to 12 μm,
Compared to Do-100H, the geometrically finished surface shape is regular and changes with more stable values. In any case, the cutting tools Normal and Do-20H show equivalent values, and stable cutting accuracy can be obtained.

Figure 6 shows the cutting tool N or m a l, Do-2.
Cutting time 28m1n for 0H and Do-100H
It shows the change in cutting resistance of the principal force Ft and the feed force Ft up to.

The cutting tool Do-20H shows the smallest value, and its fluctuation is also small. Next, Do-100H has a cutting time of 14 m.
Up to about 1n, it is the second lowest after Do-20H, but after this time the fluctuation becomes large, and especially in the principal force Ft, it becomes the largest among the three types of cutting tools. In other words, among the three types of cutting tools, DO-100H exhibits the largest variation.

As described above, according to this embodiment, the machining resistance is reduced by using a vibration damping material for the base portion 1 of the cutting tool, and by interposing an adhesive made of a polymeric material with high damping properties as the vibration damping coupling M4. Ensure absorption and attenuation. This allows the machining vibrations that act on the cutting tool to be kept to a minimum.
In addition to improving accuracy, tool life can be extended. In addition, the cutting edge can be easily attached to the base in a short time using an adhesive, which previously relied on brazing, and the adhesive can be chemically removed. , regrinding can be used effectively until the cutting edge has the ability to participate in cutting, leading to significant cost reductions.

In the above-mentioned embodiment, a cutting tool, that is, a fixed tool installed in a lathe was described, but the present invention can also be applied to a rotary tool installed in a drilling machine or the like.

〔Effect of the invention〕

As explained above, according to the present invention, vibrations generated during cutting and impacts generated during intermittent cutting can be absorbed by the vibration damping bonding layer, and cutting accuracy and cutting efficiency can be improved. In addition, by bonding the cutting edge to the base via the vibration-damping bonding layer, unlike conventional silver brazing, no skill is required for bonding, and attachment and detachment are easy. The cutting edge can be easily regenerated, resulting in significant cost reductions.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the cutting tool of the present invention;
Figure 2 is a diagram showing the maximum flank wear width and average flank wear width with respect to cutting time, and Figure 3 is a diagram showing the cutting tool No.
rma l vibration damping diagram, Fig. 4 is a vibration damping diagram of Do-20H cutting tool, Fig. 5 is a diagram showing the finished surface roughness of different cutting tools at different cutting times, and Fig. 6 is a diagram of different cutting tools. FIG. 3 is a diagram showing the main component force and feed component force of the cutting resistance. 1... Base part 2... Cutting edge part 3... Mounting recessed part 4... Vibration damping coupling layer patent applicant
1) Hongan 1 Figure 5 Figure 3 Figure 4 Procedural amendment June 9, 1988 1. Indication of case 1988 Patent Application No. 111440 2゜ Title of invention Cutting tool 3. Amendment Patent applicant 4, agent address: Iwatsuki Building 6, 6-7-16 Ginza, Chuo-ku, Tokyo
, subject to correction

Claims (4)

[Claims] (1) A cutting tool comprising a cutting edge portion and a base portion, characterized in that a vibration-damping bonding layer is interposed between the base portion and the cutting edge portion to couple the two. (2) Base portion: C; 0.8 to 3.0%; Si; 1.
0-3.0%, Ni; 25-40%, Co; 4.0-6
．． 0%, Mn; 0-2.0%, S; 0-1.0%, P;
The cutting tool according to claim 1, characterized in that the cutting tool is made of a vibration damping material containing 0 to 1.5% residual Fe as a component. (3) The vibration damping bonding layer has a tensile shear strength τt=10 to 20
MPa, viscosity η before curing is η = 30 to 40 Pa at room temperature
S, transverse elastic modulus of cured product G = 0.05 to 0.2 GPa, damping coefficient C = 3 to 5 MPa・S, spring constant of bonding layer portion 7
The cutting tool according to claim 1, characterized in that the cutting tool has a power of 0 to 130 GN/m. (4) The cutting tool according to claim 1, wherein the vibration damping bonding layer is an epoxy polyamide adhesive containing epoxy as a main component.