JPH0325861Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a throw-away type face milling cutter for cutting stainless steel, and aims to improve cutting performance by paying particular attention to the cutting blade configuration, chip evacuation performance, and tool rigidity. be.

Conventionally, this type of throw-away type face milling cutter generally has a corner angle of 45°, and there is also a corner angle of 75° for cutting stainless steel.

However, the former cannot achieve a long tool life due to chip welding during cutting, and the latter has high cutting resistance even if it achieves a long tool life. However, the maximum depth of cut was small.

For this reason, there is a demand for the development of a throw-away type face milling cutter that has improved overall aspects such as cutting edge configuration, chip evacuation, and tool rigidity so that it can have a long life when cutting stainless steel and also reduce cutting resistance. has been done.

The present invention was developed in view of the above points, and provides a high-performance indexable face mill for cutting stainless steel by considering the cutting blade configuration, chip evacuation performance, and tool rigidity. be.

Hereinafter, an embodiment of the indexable face milling cutter for cutting stainless steel according to the present invention will be described with reference to the drawings.

In FIGS. 1 and 2, 1 is a tool body forming an annular body with a center mounting hole 2,
A locator 4, an approximately square plate-shaped throwaway tip 5, and a front wedge 6 are disposed within the mounting groove 3 provided on the outer peripheral edge. In this case, the mounting groove 3 is a groove portion 4 that receives the locator 4.
A and a groove 6a for receiving the front wedge 6 are arranged in parallel. The groove bottom surfaces 4b and 6b are inclined toward the rear outer periphery with respect to the axial direction of the tool body 1, and furthermore, on the outer periphery side, side walls 4c,
6c are respectively formed to constitute a stop groove. The locator 4 has a fixing screw 7, for example, as shown in the figure.
is fixed by the throw-away tip 5.
is disposed within the tip seat 8 of the locator 4 and is pressed and fixed by the front wedge 6 provided with a tightening screw 9.

When the throwaway tip 5 is assembled into the tip seat 8 of the locator 4, the corner angle CA is 54° to 66°, the axial rake angle AR is 5° to 20°, and the radial rake angle R.
R is set within the range of 0° to -15°. Further, a chamfer 12 is formed at the apex portion of the throw-away tip 5, and this chamfer 12 is located substantially perpendicular to the axial direction of the tool body 1 and participates in cutting. As a result of this configuration, in stainless steel milling operations, conventional CA=
Compared to a 45° face mill, the cutting life is approximately twice as long, and cutting performance is improved.

The angle ranges of the corner angle CA, axial rake angle AR, and radial rake angle mentioned above are shown in Figures 6 and 7.
This was set based on the data shown in the figure. In this case, Figs. 6 and 7 show the work material
Using 6-blade SUS304 with an outer diameter of 160 mm, we created an axial rake angle.
This figure shows the change in cutting length depending on the range of AR and radial rake angle RR. The cutting conditions were as follows: cutting width W was 100 mm, face milling cutter was centered, depth of cut was 2 mm, feed f was
0.22mm/blade.

In other words, Fig. 6 shows the corner angle CA.
60°, set the radial rake angle RR to -9°, and change the axial rake angle AR (-
6°, -3°, 5°, 9°, 10°, 15°, 20°, 24°). As a result, the axial rake angle AR was found to be good in the range of 5° to 20°. In this case, when the AR was -3° and -6°, the throw-away tip 5 was damaged due to increased vibration, and at 24°, the strength of the cutting edge was weak due to a decrease in the cutting tool angle, and the tip was damaged. On the other hand, at 5° to 20°, normal wear and minute chipping occurred and the life span was reached. Also, CA=
A similar cutting test was conducted using a face milling cutter with an angle of 50° and RR = -3°, and a similar trend was observed. However, the cutting distance decreased because CA was outside the lower limit range. This is because CA is a heavy burden on the depth of cut because it affects the length of the cutting edge 11 that is actually involved in cutting.

Furthermore, Figure 7 shows the corner angle CA.
60°, and the axial rake angle AR was set to 10°, and the cutting distance was observed as the radial rake angle RR changed. As a result, the radial rake angle RR was good in the range of 0° to −15°. Note that when RR is 5°, the cutting distance has increased, but chip clogging has occurred, which is a problem.
When the angle was 18°, the cutting force increased, which was a problem.

Furthermore, in relation to chip evacuation, the outer circumferential diameter of the tool body 1 is approximately equal to the outermost circumferential edge of the throw-away tip 5 incorporated into the tool body 1. This is to improve chip evacuation when stainless steel is cut with the throw-away tip 5, and along with this, the concave tip pocket 10 also has a locator 4.
By expanding to the rear of the tool body 1 and penetrating to the outer peripheral side of the tool body 1, a space for outflow of chips is secured.
That is, the tip pocket 10 is formed around the side walls 6c and 6d of the groove 6a so as to be continuous with the outer circumferential surface of the front wedge 6, and moreover, in the direction of the groove bottom surface 6b of the groove 6a, the tip pocket 10 is formed on the front side facing the workpiece. It penetrates toward the outer periphery. As a result, the removal of cutting material is improved, and damage to the cutting edge 11 of the throw-away tip 5 due to chips is prevented.

Next, cutting examples using the throw-away type face milling cutter for cutting stainless steel according to the present invention and a comparative product will be described.

For face milling specifications, the cutting edge diameter is 160
mmφ and the number of blades is 6. As shown in FIGS. 4 and 5, the throw-away tip 5 has a chamfer 12 formed at the apex portion of the cutting edge 11, and has a substantially square plate shape with a reference inscribed circle of 15.875 mm. This is a positive chip.

Also, move the throwaway tip 5 to the locator 4.
Regarding the angular relationship when installed in the chip seat 8, the corner angle CA = 60°, the axial rake angle AR = 15°, and the radial rake angle RA = -9°. From this angular relationship, the true rake angle is calculated to be 8.69°, and the incline angle IA is 15.17°.

As a work material, Brinell hardness H _B = 166 is used.
SUS304 was selected and cut using a vertical milling machine (7.5kw) with low rigidity. In this case, the cutting conditions are: cutting speed V = 150 m/min, depth of cut d = 2
mm, feed f = 0.22 mm/tooth, and 0.30 mm/tooth were set. As a result, as shown in Figure 8, the conventional product with corner angle CA = 45° (AR = 15°, RR = -
3°) and 75° comparative product (AR=15°, RR=-15°)
It showed excellent cutting performance and good chip evacuation.

The comparative product with a corner angle of 75° was sometimes better than the inventive product when cutting with a highly rigid vertical milling machine, but the maximum depth of cut was limited to approximately 2.5 mm, so the inventive product was better than the inventive product. The results were better in terms of overall evaluation.

As explained above, the present invention takes into account the cutting edge configuration, chip evacuation performance, and tool rigidity.
Since it is particularly suitable for cutting stainless steel, improvements in work efficiency and cutting performance can be expected.

[Brief explanation of the drawing]

Fig. 1 is a partial front view of the throw-away type face milling cutter for cutting stainless steel according to the present invention, and Fig. 2 is a partial front view of the present invention.
3 is a sectional view taken along the - line in FIG. 1, FIG. 4 is a front view showing the throwaway tip, FIG. 5 is a side view thereof, and FIG. The figure is an explanatory diagram showing the change in cutting distance due to change in the axial rake angle.
FIG. 8 is an explanatory diagram showing changes in cutting distance due to changes in radial rake angle, and FIG. 8 is an explanatory diagram showing characteristics of the product of the present invention and a comparative product. 1... Tool body, 3... Mounting groove, 4... Locator, 5... Throwaway tip, 6 Front wedge,
8... Chippocket, 10... Chippocket.

Claims (1)

[Claims for Utility Model Registration] A mounting groove 3 and a tip pocket 10 are provided on the front outer periphery of the tool body 1, and within the mounting groove 3, a throw-away tip 5 having a substantially square plate shape is inserted into the locator 4. and a throw-away type face milling cutter for cutting stainless steel which is fixed by a front wedge 6, in which the mounting groove 3 has a groove 4a for receiving the locator 4 and a groove 6a for receiving the front wedge 6 arranged in parallel. Moreover, the groove bottom surfaces 4b and 6b are inclined toward the rear outer circumference with respect to the axial direction of the tool body 1, and the side walls 4c, 6b are provided on the outer circumference side.
6c are respectively formed to constitute a stop groove, and the locator 4 is connected to the groove portion 4 of the mounting groove 3.
fixed so as to be located on the a side, and in addition, the groove portion 4a
A chip seat 8 for receiving the throw-away chip 5 is formed on the side, and the throw-away chip 5 is formed with a chamfer 12 that cuts off its apex portion, and the chip seat 8 of the locator 4 is formed thereon. 8, the chamfer 12 is located substantially perpendicular to the axial direction of the tool body 1, and its corner angle CA is 54° to 66°, and the axial rake angle is
AR is 5°~20°, radial rake angle RR is 0°
The front wedge 6 is located on the groove 6a side of the mounting groove 3 and presses the throwaway tip 5 in cooperation with the tightening screw 9. The tip pocket 10 is formed around the side walls 6c, 6d of the groove 6a so as to be continuous with the outer peripheral surface of the front wedge 6, and furthermore, the tip pocket 10 is formed around the side walls 6c, 6d of the groove 6a.
In the direction, the tool body 1 penetrates from the front side facing the workpiece toward the outer circumferential side, and the outer circumferential diameter of the tool body 1 is formed by the locator 4 and the throw incorporated in the groove 4a of the mounting groove 3, respectively. A throw-away type face milling cutter for cutting stainless steel, characterized in that the cutter is set to be approximately equal to the outermost periphery of the away tip 5.