JPS6171909A - Processing blade tool - Google Patents

Abstract

PURPOSE:To prevent the tip of a blade tool from being damaged in processing of a highly hard workpiece by directing a vertical component to a rake surface of cutting resistance of the cutting blade parallely to a relief surface or in a direction of going away from the relief surface. CONSTITUTION:A processing blade tool 12 comprising a carbide material (BRM20) includes a relief surface 16 having a relief angle beta to a cutting rear surface 14 of a workpiece, and it furthermore includes a rake surface 18 having a rake angle alpha in a direction of advancement of the processing blade tool 12 from a vertical axis 1 with respect to the cutting rear surface 14 at the tip end P of the relief surface 16. These rake angles satisfy alpha>beta, and a vertical component N of cutting resistance R to the rake surface 18 is directed parallely to the relief surface 16 or a direction of going away from the relief surface 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a machining tool, and is effective for use in, for example, an end mill cutter or a wedge force cutter in milling.

(Prior Art) Conventionally, a generally used machining tool 100 has a shape as shown in FIG. This machining tool 100 has a flank 106 having a clearance angle β0 with respect to the cutting surface 104 of the workpiece 102, and the machining tool It has a rake face 108 having a rake angle α0 in the direction of travel.

(Problems that the invention attempts to resolve) However, with such a machining tool, the rake angle α0 is set to the vertical axis of the surface after cutting, and is set in the opposite direction of the machining tool progress. , the rake face 10B vertical component force N of the cutting resistance R is oriented in a direction intersecting the flank face 106. Therefore,
When cutting high-hardness materials with a large cutting resistance R, there is a problem in that the tip of the machining tool 100 is damaged (referred to as chipping) due to the vertical component N.

(Means for Solving the Problems) In view of the above-mentioned problems, the present invention aims to perform good cutting without causing chipping even when cutting high-hardness materials, and has the following configuration. . That is, in the process of cutting the surface of a workpiece by a predetermined amount of 11, the surface of the workpiece is J i'ii i
gt surface a: 2y+ A rake face having a rake angle in the cutting tool advancing direction from the vertical axis when the vertical axis to the cutting surface is taken at the forefront end of this flank surface. and the rake angle: r
Addition 7 [cutting tool], which is a value larger than the relief angle, was used.

(Example) Next, embodiments of the present invention will be described based on the drawings.

Fig. 3 cL is a diagram showing the case where the present invention is used in a four-blade end mill cutter, and Fig. 4 is a perspective view of the case where it is used in a one-blade carbide cutter. Both of these cutting edges have shapes as shown in FIG. 1, and the surface of the workpiece 10 is cut with a depth of cut t.

The machining blade p, , 1.2 is made of carbide +tlRM2o) and has a flank 16 having a clearance angle β with respect to the cut surface 14 of the workpiece 10, and further has a tip P of this flank 6. Considering the vertical axis e with respect to the surface 14 after cutting in
It has a rake face 18 having an angle α. This rake angle α is greater than the clearance angle β, and the component force N perpendicular to the rake face 18 of the cutting force R is parallel to the clearance face 16 or in a direction away from the clearance face 16. Zunaka F ``.

The force indicated by Fc indicates the vertical component force and horizontal component force of the cutting resistance R, and the machining force is 12 and 1 is -U.
It acts as a shearing force. Generally speaking, a clearance angle of 6" to 8° is required for highly advanced workpieces (A), so if the clearance angle is set to 7° (the clearance angle α is 7°).
The above is necessary.

FIG. 5 is a diagram showing the relationship between the Lk degree (93 cut) and the shear stress exerted on the workpiece and the processing force υ. As can be seen from this figure, the shear stress of the workpiece decreases rapidly from around 60Q 'C in both cases of 5KDII and 5KD6 j, but compared to this, the shear stress of the processing tool decreases only slightly. be. FIG. 6 shows the shear stress difference between the cutting tool and the workpiece shown in FIG. Stable sharpness! To perform ill, the stress difference of 11i is 18
0kg/mm2 or more -1- is required, and from this figure 5KD
61 has a machinable range between low temperature (low cutting speed) and high 1 grade (high cutting speed). Well, if S l < D 11, the shear stress difference required for stable cutting can be obtained in the high temperature range.

The seventh is the experimental results of the cutting life versus cutting speed of the workpiece 5KD11 using the rake angle α as a parameter.
The Rockwell hardness of the work material 5KI)-11 is HRC-6.
1. The machining tool used was a 4-wedge carbide engraver with a diameter of ψ12. The cutting was carried out by dry cutting with a depth of cut of 0.2 mm and a feed rate of 0.1 mm/blade. The cutting speed at which the cutting life reaches its peak is approximately 60 m at all levels.
/min.

The MAX cutting life achieved in the high temperature range is considered to be due to the effect of increasing the shear surface temperature of the workpiece through high-speed cutting and lowering the shear temperature. Furthermore, when life promotion and the It shift (of the stress difference) are made to correspond, the trends are almost the same. From this, it can be seen that the difference in shear stress is also a factor that determines the cutting life, and as can be seen from FIG. 6, cutting can be carried out at a high cutting temperature (800° C. or higher). Furthermore, it can be seen from FIG. 7 that the cutting life is the longest when the rake angle α is set to α-15°. The example shown in FIG. 7 is an example when α0-4° is used when a cutting tool having a shape as shown in FIG. 2 is used.

Figure 9 shows a workpiece of 5KDII and a cutting speed of 60m/
The graph shows the relationship between the cutting length and the amount of wear of the cutting tool when the cutting depth Q is 2 mm, the feed is 0.1 mm/blade, and the rake angle is α-15°.

Moreover, FIG. 10 shows the relationship between the cutting length and the surface roughness after cutting under the same conditions as in FIG. 9.

According to the study by the present inventors, when the workpieces are 5KDll and 5KD61, the optimal cutting speed is 60m/m respectively.
It was found that the speed was 50m/min. It has also been found that the optimum rake angle α is 15°, and that chipping does not occur if the rake angle is greater than that, but an upward slipping phenomenon occurs.

(Results of the Invention) As explained above, when the machining tool of the present invention is used, the component of cutting force perpendicular to the rake face is parallel to the flank face or in a direction away from the flank face. Even when machining highly hard workpiece materials, it is possible to perform the machining satisfactorily without the chipping phenomenon of the cutting tool.

[Brief explanation of the drawing]

Figure 1: 1 shows an embodiment of the present invention, Figure 2 shows a conventional example, Figure 3 shows the present invention applied to a four-way en 1-mill cutter, and Figure 4 shows the present invention applied to a 1-mil cutter. Figure 5 is a diagram showing the relationship between cutting temperature and shear stress. Figure 6 is a diagram showing the relationship between shear stress difference between the workpiece and the cutting tool depending on cutting temperature. Figure 7 shows the relationship between cutting speed and cutting life using the rake angle as a parameter, Figure 8 shows the relationship between cutting length and amount of wear on the cutting tool, and Figure 9 shows the relationship between cutting length and surface roughness. FIG. 10... Workpiece, 12... Machining tool, 14...
Surface after cutting, 16... flank surface, 18... cutout surface,
α: Relief angle, β: Relief angle.

Claims (1)

[Claims] In a machining tool made of a carbide material that cuts the surface of a workpiece by a predetermined width, a flank surface having a relief angle with respect to the surface after cutting of the workpiece is provided, and a clearance angle is formed at the front end of the flank surface with respect to the surface after cutting. A machining tool comprising: a rake surface having a rake angle in a direction in which the machining tool advances from the vertical axis when the vertical axis is taken, the rake angle having a value larger than the clearance angle.