JPH088011Y2 - Throwaway type rolling tool - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a throwaway type milling tool such as an end mill, and more specifically, it is suitable for use in grooving or side machining of a work material. Related to a way-type rolling tool.

[Prior Art] Conventionally, as a throwaway type rolling tool of this type, as shown in, for example, FIGS. 7 to 9, a plurality of chips 1 each having a triangular flat plate shape are mounted on a chip mounting seat 3 of a supporter 2. After being inserted, it is inserted into the groove 5 of the tool body 4 together with the supporter 2, and the chip 1 and the supporter 2 are inserted into the groove 5 and the wedge members 6 and 7 are pressed to press the tool body 4.
An end mill having a configuration integrated with is known. Then, in the end mill having such a configuration, by rotating the tool main body 4 around its axis O,
The main cutting edge 8 of the chip 1 projecting from the outer circumference of the tool and the sub cutting edge 9 projecting at the tip of the tool are cut into the work material to perform a predetermined cutting process.

By the way, in order to process a work material into a flat surface by the end mill having such a configuration, the main cutting edge 8 draws a cylindrical surface-shaped rotation trajectory around the tool axis O, in other words,
Positioning the chip 1 so that the one main cutting edge 8 is equidistant from the tool axis O from the front end P ₁ to the rear end P ₂ of the chip 1 mounted on the tool body 4. After that, it is necessary to mount it on the tool body 4.

Therefore, in the tool body 4, the side surface 2a of the supporter 2 and the wall surface 5a of the groove portion 5 are brought into close contact with each other and the chip 1
Side 1a, restraint surface 3a of 1b and chip mounting seat 3, being in contact with and 3b, both ends P ₁ of the main cutting edge 8 of the chip 1, P ₂
From the tool axis O to r ₁ , r ₂ (hereinafter, turning radius r
₁ and r ₂ . ) Are matched so that the wall surface 5a and the restraint surface
The shapes of 3a and 3b have been determined.

However, such matching of the turning radii r ₁ and r ₂ of the chip 1 as described above may not be sufficient to improve the flatness of the machined surface of the work material.

That is, as shown in FIGS. 9 and 10, when the chip 1 is mounted so as to be inclined with respect to the tool axis direction at a predetermined rake face θ, as long as the main cutting edge 8 of the chip 1 is linear, The central portion of the main cutting edge 8 is retracted to the tool center side with respect to the rotation locus R drawn by both ends P ₁ and P ₂ according to the surface θ. Therefore,
In such a case, the rotation path drawn by the main cutting edge 8 around the tool axis forms a drum shape, and the machined surface cut at the center of the main cutting edge 8 projects beyond the machined surfaces formed by the ends P ₁ and P _2. The flatness of the machined surface may be deteriorated.

Therefore, when the chip 1 is mounted in a tilted manner in this way, as shown in FIG. 11, a chip 10 in which the main cutting edge 8 has a convex arc shape is used, and the central portion of the main cutting edge 8 is relatively moved. By projecting to the outer peripheral side of the tool, the rotation trajectory of the main cutting edge 8 is changed from the front end P ₁ to the rear end P _2.
Had been matched up to.

[Problems to be Solved by the Invention] By the way, according to the throwaway type rolling tool using the chip 10 having the above-mentioned convex arc-shaped main cutting edge 8, the tool body 4 is idled around the tool axis O. Main cutting edge 8
Draws a locus in the shape of a cylindrical surface, so when the workpiece 11 is grooved as shown in FIG.
It is theoretically possible to process it into a plane orthogonal to 1b.

However, in actual cutting, due to the cutting resistance applied to the main cutting edge 8, the tip side of the tool body 4 is placed on the wall surface 11 of the work material 11.
Since it is flexibly deformed in the direction away from a, the cutting amount of the front end P ₁ of the main cutting edge 8 becomes smaller than that of the rear end P ₂ as shown in FIG. Therefore, the groove wall surface 11a may not be processed into a plane orthogonal to the bottom surface 11b.

Further, as shown in FIG. 14, in particular, when the tool body 4 is fed in stages in the axial direction to cut the wall surface 11a in multiple steps, the wall surface 1a formed in the previous cutting process is used.
However, in the next cutting, the secondary cutting edge 9 on the rear end side of the main cutting edge 8 was scraped off, and as a result, the wall surface 11a was formed in a saw-tooth shape, and the flatness was sometimes significantly deteriorated.

This invention was made under such a background,
An object of the present invention is to provide a throwaway type rolling tool capable of accurately processing a work material into a flat surface even when the tool body is flexibly deformed by cutting resistance.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a restraining surface of a chip mounting seat that abuts a side surface of a chip with a rear end of the one main cutting edge facing the tool base end side. , Radius 0.03mm ~ 0.09mm around the tool axis line from the tip of the one main cutting edge facing the tool tip side
It is tilted to draw a small arc locus.

In this case, the chip mounting seat may be integrally formed on the outer peripheral portion of the tip of the tool body, or may be formed on a supporter detachably mounted in the groove of the tool body as in the above-mentioned conventional example. It may be.

[Operation] According to the above configuration, in the state where the chip is mounted on the tool body, the tip of the main cutting edge that faces the tool tip side projects more toward the tool outer peripheral side than the rear edge side of the main cutting edge that faces the tool rear edge. Therefore, when the tip portion of the tool body is flexibly deformed during cutting, the difference in the protrusion amount is absorbed and the turning radii of both ends of the main cutting edge are matched. Therefore, by curving the main cutting edge in accordance with the rake face of the chip, it is possible to make the rotational half radii of the respective parts of the main cutting edge during actual cutting match from the tip to the rear end.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. The same components as those in the conventional example described above are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 1 to FIG. 3, in the end mill of this embodiment, a triangular flat plate-shaped chip 10 having a main cutting edge 8 having a convex arc shape is inserted into the chip mounting seat 3 of the supporter 2. It is inserted into the groove portion 21 of the tool body 20 together with the supporter 2, and the chip 10 and the supporter 2 are pressed by the wedge members 6 and 7 inserted in the groove portion 21 to be integrated with the tool body 20.

Here, the groove portion 21 is in close contact with the side surface 2a of the supporter 2 and positions the supporter 2 in the tool radial direction, and the rear end surface 2b of the supporter 2 is in close contact with the supporter 2 so that the supporter 2 is aligned with the tool axis line. It has a second wall surface 21b that is positioned in the direction and a bottom surface 21c that is in close contact with the lower surface 2c of the supporter 2. The bottom surface 21c is mounted on the supporter 2 in the same manner as the conventional tool body 4 described above. In order to give the chip 10 a predetermined rake angle θ, it is formed in an inclined surface inclined in a predetermined direction with respect to the tool axis direction.

Further, the front end portion 23 of the first wall surface 21a has a rear end portion 2
The tip mounting seat 3 of the supporter 2 which is formed in the shape of an inclined surface projecting to the outer peripheral side of the tool more than 4 and comes into contact with the side surfaces 10a, 10b of the chip 10 has the constraining surfaces 3a, 3b of a conventional end mill. Compared to the tool rear end side (right side in Fig. 1)
It is positioned so that it is tilted to.

Inclination angle α of the first wall surface 21a with respect to the tool axis O
Is set appropriately according to the cutting conditions, the turning radius of the tool, and the like.
The rear end P of the main cutting edge 8 of the chip 10 mounted on the chip mounting seat 3 when mounted in close contact with 1b and the bottom surface 21c
₂ is a radius of 0.03 mm to 0.09 mm toward the center in the tool radial direction with respect to the rotation locus C drawn around the tool axis O by the tip P ₁ of the main cutting edge 8.
Of the main cutting edge 8 at both ends P
It is defined that the relationship of r ₁ −r ₂ = 0.03 mm to 0.09 mm is established between the turning radii r ₁ and r ₂ at ₁ and P ₂ (see FIG. 4).

Thus, more than in the configured end mill as, in the unloaded condition of the tool body 20, the rear end P ₂ is the tool radially center side than the tip P ₁ of the main cutting edge 8, as shown in FIG. 4 Therefore, when cutting the work material while maintaining such a state, theoretically, as shown in FIG. 5 (a), the cutting amount of the rear end P ₂ of the cutting edge 8 is It becomes smaller than the cutting depth of the tip P ₁ and the wall surface 11a (work surface) of the work material 11 and the bottom surface 1 of the groove portion
The angle β with 1b is smaller than 90 °. Further, as shown in FIG. 5 (b), when the tool main body 20 is sent out stepwise in the tool axis direction and the wall surface 11a is cut in plural times, the wall surface 11a is mainly the tip of the main cutting edge 8. The wall surface 11a is scraped off on the side to form a saw blade shape.

However, when the main cutting edge 8 is actually used for machining, as described above, the tip side of the tool body 20 is bent and deformed in the direction away from the wall surface 11a, and the cutting on the tip P ₁ side of the main cutting edge 8 is performed. Since the amount decreases relatively, the difference between the turning radii r ₁ and r ₂ is absorbed. Therefore, the difference between the turning radii r ₁ and r ₂ is set equal to the difference between the bending amounts of the both ends P ₁ and P ₂ of the main cutting edge 8 due to the bending deformation of the tool body 20, and the main cutting edge 8 is moved to the tip 10 of the chip 10. By curving in accordance with the rake face θ in the tool axis direction, the radius of gyration of the main cutting edge 8 during actual cutting can be made uniform from the leading end P ₁ to the trailing end P _2. As shown in FIG. 6 (a), the wall surface 11a of the work material 11 can be formed in a plane exactly orthogonal to the bottom surface 11b. Further, as shown in FIG. 6 (b), the tool main body 20 is gradually fed out in the axial direction so that the wall surface 11
Even when cutting a in multiple steps, it is possible to prevent interference between the auxiliary cutting edge 9 and the wall surface 11a that are continuous to the rear end P ₂ side of the main cutting edge 8,
The wall surface 11a can be processed into a flat surface orthogonal to the bottom surface 11b.

Further, according to this embodiment, as shown in FIG. 5 (b), even when the bending deformation of the tip portion of the tool body 20 is small and the turning radii r ₁ and r ₂ are not absorbed, Interference between the auxiliary cutting edge 9 adjacent to the rear end P ₂ of the main cutting edge 8, that is, the auxiliary cutting edge 9 that should be used simultaneously with the main cutting edge 8a facing the tool rear end side and the wall surface 11b of the work material 11. Is definitely avoided,
It is possible to prevent unnecessary wear of the unused auxiliary cutting edge 9 and improve the chip life.

In the above embodiments, the end mill equipped with the chip 10 in the form of a triangular flat plate is described, but the present invention is not limited to this, and it goes without saying that chips of various shapes such as a square chip can be used. is there. Also,
In particular, the shape of the main cutting edge 8 is not limited to the convex arc shape. For example, when the rake angle θ of the chip is 0 °, a chip having a linear main cutting edge may be used.

Further, in this embodiment, the first wall surface 21 of the groove portion 21 formed in the tool body 20 is particularly used to incline the chip mounting seat 3.
Although a is formed on the inclined surface inclined in a specific direction with respect to the tool axis O, the present invention is not limited to this, and the groove portion is not limited to this.
Even if 21 is the same as the conventional one, the chip mounting seat 3 of the supporter 2
The same effect can be obtained by inclining the constraining surfaces 3a and 3b. In addition, the tip mounting seat 3
Even if it is a throwaway type cutting tool in which the chip is mounted without using the supporter 2 by integrally molding, the same effect can be obtained by inclining the chip mounting seat toward the tool rear end side as compared with the conventional case. .

[Advantage of the Invention] As described above, according to the throwaway type rolling tool of the present invention, the tip side of the main cutting edge of the chip is positioned so that the turning radius is larger than that of the rear end side. When the tip side of the tool body is flexibly deformed during cutting, the difference in the radius of gyration is absorbed.

Therefore, by setting the difference between the turning radii to be equal to the difference between the bending deformation amounts at both ends of the main cutting edge at the time of cutting, the turning radii at both ends of the main cutting edge at the time of cutting are made equal to each other, and the processed surface of the work material is Can be formed on a flat surface with desired accuracy.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention.
1 is a plan view of the tool, FIG. 2 is a view from the direction II in FIG. 1, FIG. 3 is a view from the direction III in FIG. 2, and FIG.
The figure shows a state in which the chip is mounted on the tool body, projected from the tool tip side, and FIGS. FIGS. 6 (a) and 6 (b) are views showing the state of the machined surface when the tool of the embodiment is actually used for cutting, and FIGS. 7 to 9 show conventional examples. FIG. 7 is a plan view of the tool, FIG. 8 is a view from the direction VIII in FIG. 7, FIG. 9 is a view from the direction IX in FIG. 7, and FIG. Fig. 11 is a projection view of the tip of the tool when the tool has a chip with a linear main cutting edge.
The figure shows a projection of the state when the chip with a convex cutting arc-shaped main cutting edge is mounted on the conventional tool from the tool tip side. FIGS. 13 and 14 are views showing a theoretical state of the machined surface, and FIGS. 13 and 14 are diagrams showing the state of the machined surface when the work material is actually machined by the chip shown in FIG. 2 ... Supporter, 3 ... Chip mounting seat, 3a / 3b ... Restraining surface, 8 ... Main cutting edge, 10 ... Throwaway chip, 20 ...
… Tool body, 21 …… Groove.

Claims (2)

[Scope of utility model registration request] 1. A groove portion that opens to the tip and the outer periphery of the tool body is formed on the outer peripheral portion of the tip of the tool body that is rotated around the axis, and the groove portion is in contact with the side surface of the flat-shaped throwaway chip. A chip mounting seat having a constraining surface for contacting and positioning the throwaway chip is formed, and the throwaway chip has a main cutting edge formed on the ridge of the chip mounting seat protruding toward the outer peripheral side of the tool. In a throwaway type rolling tool that is removably mounted in a state where the rear end of the constraining surface of the chip mounting seat faces the tool base end side of the one main cutting edge, the tool tip side is A throwaway type rolling tool characterized by being inclined so as to draw an arc locus smaller by 0.03 mm to 0.09 mm in radius around the tool axis than the tip of the one main cutting edge facing. 2. A throwaway milling tool according to claim 1, wherein a supporter is removably inserted into the groove of the tool body, and the tip mounting seat is formed at the tip of the supporter. tool.