JPH11300518A - Brooch cutter, and brooch machining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the brooch cutting high in efficiency, low in cost and considerate in environment. SOLUTION: The brooch cutting capable of achieving the dry cut to achieve the cutting without using any cutting oil, unnecessary in use (purchase) of the cutting oil and maintenance, high in efficiency, low in cost and considerate in environment is realized by using a brooch cutter 11 in which a large number of cutting teeth 13 are arranged on an outer circumference of a body 12 in the axial direction, and using the broach cutter 11 in which at least one layer of a film of the composition of (Ti(1-x) Alx )(Ny C(1-y) ), to satisfy the inequalities of 0.2<=x<=0.9, and 0.2<=y<=1.0 is coated on at least a flank 14 of the cutting teeth 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broach cutter used for broaching and a broaching method using the same.

[0002]

2. Description of the Related Art A general broaching situation will be described with reference to FIG. FIG. 8 shows a schematic configuration of a processing section in the broaching machine.

In a broaching machine 1, a work 2 is fixed to a table 4 by a fixture 3, and a broach cutter 5, which is a tool involved in machining, is attached to a cutter head 6. The material of the broach cutter 5 is a high-speed tool steel, and the broach cutter 5 is provided with a large number of cutting edges whose dimensions sequentially increase in the axial direction.

[0004] By providing a linear motion to a broach cutter 5 having a large number of cutting edges of sequentially increasing dimensions, the cutting edges are cut into the work 2 and the work 2 is processed. The feed speed of the broach cutter 5 is usually about several m / min to several tens m / min, and a cutting oil 7 is supplied from a nozzle 8 to a cutting portion during processing. By supplying the cutting oil 7 to the cutting portion, lubrication and cooling of the cutting portion are performed.

In recent years, there has been a strong demand for environmental measures. Cutting oils not only deteriorate the working environment, such as foul odors, fouling due to splashing, and generation of oil smoke, but also cause air pollution when processing waste oil. Causes environmental degradation.
For this reason, in the field of machining, there is an increasing need for so-called dry cutting in which cutting is performed without using a cutting oil from the viewpoint of the environment.

[0006]

In the field of the broaching machine 1, as an environmental measure, there has been a demand for dry cutting in which cutting is performed without using a cutting oil. However, with the current broach cutter 5, if cutting is performed by dry cutting without using a cutting fluid, the wear of the cutting edge becomes severe and the finished surface roughness is greatly deteriorated. Further, the intended processing accuracy cannot be obtained due to the cutting heat at the time of processing. Therefore, in the field of broaching, dry cutting cannot be performed without using a cutting fluid at present.

The present invention has been made in view of the above circumstances, and has as its object to provide a broach cutter and a broaching method capable of performing broaching by dry cutting.

[0008]

In order to achieve the above object, a broach cutter according to the present invention is a broach cutter in which a number of cutting edges are arranged along an axial direction. _(1-x) Al _x ) (N _y C _(1-y) ) 0.2 ≦ x ≦ 0.9 0.2 ≦ y ≦ 1.0 At least one film is coated.

In order to achieve the above object, the broaching method of the present invention is directed to a broaching method for performing cutting using a broach cutter having a large number of cutting edges arranged in an axial direction. at least flank, using a _{(Ti (1-x) Al} x) broach cutter _{(N y C (1-y} )) 0.2 ≦ x ≦ 0.9 0.2 ≦ y ≦ 1.0 a composition of the membrane is at least one layer coated In addition, cutting is performed by dry cutting in which cutting is performed without using a cutting oil. Further, the cutting part is characterized in that cutting is performed by blowing air.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of a broaching machine for carrying out a broaching cutter and a broaching method according to the present invention will be described with reference to FIGS. FIG. 1 shows a cross section of a main part of a broach cutter according to an embodiment of the present invention, and FIG. 2 shows a schematic configuration of a broaching machine for performing a broaching method according to an embodiment of the present invention.

As shown in FIG. 1, the broach cutter 11
Are a number of cutting edges 1 along the axis on the outer periphery of the rod-shaped main body 12.
3 are arranged in dimensional order. The material of the broach cutter 11 is SKH51, and the cutting edge 13 including the flank 14 is Ti
A film of Al nitride or TiAl carbonitride is coated.

As shown in FIG. 2, in the broaching machine 21,
The work 22 is fixed to the table 24 by the fixture 23, and the broach cutter 11 is attached to the cutter head 25. By providing a linear motion to the broach cutter 11 in which a large number of cutting edges 13 are arranged in the axial direction, the cutting edges 1
3 is cut into the work 22, and the work 22 is processed. The broaching machine 21 is provided with an air nozzle 26,
Cooling air 27 is blown from the air nozzle 26 toward the cutting portion being processed.

A first embodiment of the broaching method of the present invention using the above-described broach cutter 11 will be described. In the first embodiment, the relationship between the x value of the coating film having the composition of (Ti _(1-x) Al _x ) N and the finished surface roughness is examined by variously changing the value of x. It is an example for grasping the range. As the broach cutter 11, one having a coating thickness of 1.7 μm and one or more materials coated in a single-layer or multi-layer coating is used. The material of the work 22 is carburized steel (HB120 to HB250),
The tooth profile to be machined is an involute tooth profile with module 2.5, 40 teeth and a pressure angle of 20 degrees. The cutting length is 20mm, the cutting speed is 3.0m / min, the value of x of the coating film is 0.1,
Seven types of 0.2, 0.3, 0.5, 0.8, 0.9, 1.0 were prepared. The result of the cutting is shown in FIG.

In FIG. 3, the work finished surface roughness is
This is the worst value when 100 workpieces 22 are cut at a cutting speed of 3.0 m / min. As shown in the figure, general TiN (x = 0)
As compared with the case of cutting by wet cutting using a cutting oil with a broach cutter coated with the above film (indicated by ● in the figure), the same degree of finished surface roughness was obtained for all compositions.

In particular, (Ti _(1-x) Al _x ) N where _x is 0.5
The best value was obtained for the finished surface roughness when a film having the following composition was coated. This is because when the value of x increases, the film softens, and when the value of x decreases, the oxidation resistance of the film decreases. Is estimated to be stable, and the finished surface roughness of the workpiece has a minimum value.

Therefore, as the broach cutter 11, (Ti
By coating a film with the composition of _(1-x) Al _x ) N and the value of x being 0.2 ≦ x ≦ 0.9, it is possible to obtain the same finished surface roughness as before without using cutting oil. It turns out that it is possible.

A second embodiment of the broaching method according to the present invention will be described. In the second embodiment, (Ti _0.5 Al _0.5 ) (N _y
This is an example for variously changing the value of y of the coating film having the composition of C _(1-y) ), examining the relationship with the finished surface roughness, and grasping the optimum range of y value. As the broach cutter 11, a single layer coating of a film having the composition of (Ti _0.5 Al _0.5 ) (N _y C _(1-y) ) or at least one layer of the multilayer coating is made of (Ti _0.5 Al _0.5 ) (N _y C
_A coating of a film having the composition of _(1-y) ) is used. The material of the work 22 is carburized steel (HB120 to HB240), and the tooth shape to be machined is a module 2.5, the number of teeth is 40, the pressure angle is
It has a 20-degree involute tooth profile. The cutting length is 20mm,
The cutting speed is 3.0m / min, and the value of x of the coating film is
Six types of 0.1, 0.2, 0.3, 0.5, 0.7 and 1.0 were prepared. The result of the cutting is shown in FIG.

In FIG. 4, the work finished surface roughness is
This is the worst value when 100 workpieces 22 are cut at a cutting speed of 3.0 m / min. As shown in the figure, in the case of 0.2 ≤ y ≤ 1.0, a conventional (typical broach cutter coated with a TiN (x = 0) film was used for cutting by wet cutting using a cutting fluid (indicated by ● in the figure). )), The same degree of finished surface roughness was obtained. It is considered that the reason why the finished surface roughness deteriorates as the value of y decreases is that the oxidation resistance decreases due to the increase of C instead of N, and the wear of the cutting edge is accelerated.

Therefore, as the broach cutter 11, (Ti
_In the composition of _0.5 Al _0.5 ) (N _y C _(1-y) ), the value of y is 0.2 ≦ y
It can be seen that by coating a film with ≦ 1.0, it is possible to perform processing to obtain the same finished surface roughness as before without using a cutting oil.

A third embodiment of the broaching method according to the present invention will be described. The third embodiment is an example in which the thickness of a coating film composed of a composition of (Ti _0.5 Al _0.5 ) N is changed, the relationship with the finished surface roughness is examined, and an appropriate value of the film thickness is grasped. It is. As a broach cutter 11 (Ti _0.5 A
l _0.5) obtained by single-layer or multi-layer coating film having a composition of N is used. The material of the work 22 is carburized steel
(HB120-HB240), and the tooth profile to be processed is module 2.5
It has an involute tooth profile with 40 teeth and a pressure angle of 20 degrees.
Cutting length is 20mm, cutting speed is 3.0m / min, coating film thickness (μm) is 0.2, 0.5, 1.7, 2.5, 4.
Nine types of 0, 6.0, 8.0, 10.0, 11.0 were prepared. The result of the cutting is shown in FIG. Here, the film thickness indicates the thickness of a single layer in the case of a single layer, and indicates the total thickness of a plurality of layers in the case of a multilayer.

In FIG. 5, the work finished surface roughness is
This is the worst value when 100 workpieces 22 are cut at a cutting speed of 3.0 m / min. In the figure, ○ indicates the relationship between the film thickness and the finished surface roughness of the workpiece when a single layer of the film composed of (Ti _0.5 Al _0.5 ) N is coated.
The relationship between the film thickness and the finished surface roughness of the workpiece when five layers of coating of 05 μm TiN are sandwiched between (Ti _0.5 Al _0.5 ) N is shown.

In the case of a single layer, when the film thickness is 0.5 μm, the thickness is 1.7 μm.
The surface roughness is reduced by about 20% compared to m
From 1.7 μm to 8.0 μm, the finished surface roughness is constant irrespective of the film thickness, and when the film thickness is 10.0 μm, it deteriorates to about 1.5 times that of 1.7 μm. However, when the film thickness is reduced to 0.2 μm, the finished surface roughness deteriorates about 4.4 times compared to the case of 1.7 μm and deteriorates rapidly. On the other hand, when the film thickness is 11.0 μm, peeling of the film occurs, and the finished surface roughness rapidly deteriorates. In the case of the multilayer, a slightly better finished surface roughness was obtained than in the case of the single layer.

Accordingly, it is understood that the thickness of the coating film of the broach cutter 11 is preferably 0.5 μm or more and 10.0 μm or less, and it may be a single layer or a multilayer.

A fourth embodiment of the broaching method according to the present invention will be described. In the fourth embodiment, a broach cutter 11 coated with a film composed of (Ti _0.5 Al _0.5 ) N 2 is used.
This is an example for ascertaining the dry cut performance exerted on the finished surface roughness of various workpiece materials in cutting by the method. As the broach cutter 11, a single layer (1.7 μm thick) of a film having a composition of (Ti _0.5 Al _0.5 ) N was used. The material of the work 22 is A: carburized steel and case hardened steel (HB120 ~
HB250), B: Carbon steel (HB150-HB250) and C: Cast iron (HB150
~ HB250), and the tooth profile to be processed is module 2.
5, Involute tooth profile with 40 teeth and 20 degree pressure angle.
The cutting length was 20 mm, and the cutting speed was 3.0 m / min. The result of the cutting is shown in FIG.

In FIG. 6, the work finished surface roughness is
This is the worst value when 100 workpieces 22 are cut at a cutting speed of 3.0 m / min. As can be seen from the figure, (Ti _0.5 Al _0.5 ) N
Broach cutter 1 coated with a film consisting of
When dry cutting is performed using
In all cases, it was confirmed that the finished surface roughness of the workpiece was about 4 to 8 μmRmax, which was almost the same as wet cut.

A fifth embodiment of the broaching method according to the present invention will be described. In the fifth embodiment, a broach cutter 11 coated with a film composed of (Ti _0.5 Al _0.5 ) N 2 is used.
This is an example for grasping the tool life in cutting by cutting. Using a single layer (1.7 μm thick) of a film composed of (Ti _0.5 Al _0.5 ) N (product of the present invention) as the broach cutter 11, the flank wear was examined by performing dry cutting. For comparison, a single layer (1.9 μm film thickness) of a general TiN film coated as a broach cutter (conventional product) was used, and the flank wear was examined by performing a wet cut using a cutting oil. The material of the work 22 is carburized steel (HB120 to HB250), and the tooth profile to be machined is an involute tooth profile having a module 2.5, 40 teeth, and a pressure angle of 20 degrees. The cutting length was 20 mm, and the cutting speed was 3.0 m / min.
The result of the cutting is shown in FIG.

FIG. 7 shows a comparison of the maximum wear amount on the flank of the cutting edge portion when the same number (6000) of workpieces are cut by the product of the present invention and the conventional product. As can be seen from the figure, even if dry cutting is performed with the product of the present invention,
The flank wear was equivalent to that of the conventional wet cut, and it was confirmed that the tool life was equivalent to that of the conventional wet cut.

[0028]

The broach cutter according to the present invention is a broach cutter having a large number of cutting edges arranged along the axial direction.
At least the flank face of the cutting edge is at least more coating _{(Ti (1-x) Al} x) (N y C (1-y)) 0.2 ≦ x ≦ 0.9 0.2 ≦ y ≦ 1.0 a composition of film Therefore, even if dry cutting is performed without using a cutting oil, the wear of the cutting edge does not become severe and the finished surface roughness does not deteriorate. As a result, broaching can be performed without using a cutting fluid.

Further, the broaching method of the present invention is a broaching method for performing cutting using a broach cutter in which a number of cutting edges are arranged along the axial direction. _(1-x) Al _x ) (N _y C _(1-y) ) 0.2 ≦ x ≦ 0.9 0.2 ≦ y ≦ 1.0 Using a broach cutter coated with at least one layer of a film, without using a cutting oil. Since the cutting process is performed by dry cutting, the use of a cutting fluid (purchase) and broaching without maintenance can be performed. As a result, high efficiency, low cost and environmentally friendly broaching can be realized.

Further, since cutting is performed by blowing air to the cutting portion, a high efficiency and low cost broaching process can be realized without causing the chips to be caught and without causing the cutting portion to be heated to a high temperature.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a broach cutter according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a broaching machine that performs a broaching method according to an embodiment of the present invention.

FIG. 3 is a graph showing a state of a work finished surface roughness.

FIG. 4 is a graph showing a state of a work finished surface roughness.

FIG. 5 is a graph showing a relationship between a film thickness and a work finished surface roughness.

FIG. 6 is a graph showing a relationship between a work material and a work finished surface roughness.

FIG. 7 is a graph showing a state of a flank wear amount.

FIG. 8 is a schematic configuration diagram of a processing unit in the broaching machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Broach cutter 12 Main body 13 Cutting edge 14 Flank 21 Broaching machine 22 Work 23 Attachment 24 Table 25 Cutter head 26 Air nozzle 27 Air

Claims (3)

[Claims] 1. A broach cutter having a large number of cutting edges arranged along an axial direction, wherein at least a flank of the cutting edges includes (Ti _(1-x) Al _x ) (N _y C _(1-y) ) A broach cutter characterized in that at least one layer of a film having a composition of 0.2 ≦ x ≦ 0.9 0.2 ≦ y ≦ 1.0 is coated. 2. A broaching method for performing a cutting process using a broach cutter having a large number of cutting edges arranged along an axial direction, wherein at least a flank of the cutting blade has (Ti _(1-x) Al _x ) ( N _y C _(1-y) ) 0.2 ≤ x ≤ 0.9 0.2 ≤ y ≤ 1.0 Use a broach cutter coated with at least one layer of a film, and perform cutting by dry cutting without using a cutting oil. A broaching method characterized by the above-mentioned. 3. The broaching method according to claim 2, wherein air is blown to the cutting portion to perform cutting.