JP5580239B2 - Milling tools - Google Patents

Description

  The present invention relates to a milling tool used for cutting, and more particularly to an edge-exchangeable milling tool used for cutting difficult-to-cut materials such as super heat resistant alloys.

A milling tool having this kind of blade tip replaceable tip is a rotary tool widely used for die processing and material cutting processing, and the tip shape is polygonal and the rake face by the blade tip is circular, A so-called Marukoma chip is known.
Usually, when scraping off the planar shape, a milling tool using a tip whose tip has a polygonal shape such as a square is used. However, since the chip has a polygonal shape, a three-dimensional digging process or the like becomes a stepped process, resulting in unevenness in machining allowance in the finishing process, and is not suitable for finishing a precise shape. Further, the cutting resistance is large and the tool is likely to be deformed.

On the other hand, a milling tool using a round piece insert is a plurality of round piece inserts having a circular rake face arranged in the circumferential direction of the rotary tool, and the cutting load is distributed and received by the entire circular cutting edge. Since stress concentration or the like hardly occurs and is not easily broken, there is an advantage that durability is high with respect to cutting of difficult-to-cut materials. In addition, since the cutting edge is circular, the connection between the passes is smooth, the machining allowance for the next process can be made uniform, and the shape of the cutting edge on the track is a curved surface. Cheap.
Furthermore, the chip thickness at the cutting point smoothly changes from 0 ° (very thin cut) to 90 °, so that the feed can be set high, which is particularly useful for roughing.
Moreover, the round piece insert can use the entire circumference of the circle as the cutting edge, so when a part of it is worn, a new cutting point can be set by slightly rotating the insert, which is advantageous in terms of cost. It becomes.

Because of these advantages, it has been increasingly used in roughing and semi-finishing in the die machining and contour cutting processes, and also in roughing difficult-to-cut materials such as super heat-resistant alloys. Even when a hard metal material is used for the round piece insert, the life of the hard-to-cut material may be drastically reduced, resulting in reduced cutting efficiency and reduced tooling efficiency such as increased tool change frequency. It becomes a problem.
Therefore, against the backdrop of recent improvements in the performance of ceramic materials, high hardness and extremely high strength ceramics are used as the round piece chip material, and high-speed cutting is performed to cut super heat-resistant alloys with high removal efficiency. Processing is also possible.

However, such a ceramic round piece chip is supplied in a simple cylindrical shape from the viewpoint of manufacturing cost, and therefore the clearance angle on the side surface of the cylinder cannot be secured with a single chip.
Therefore, machining by a milling tool using a round piece chip is generally performed by cutting on the bottom surface side by designing the angle of the mounting surface so as to ensure a clearance angle on the bottom surface side.

  However, in the case of performing a three-dimensional digging cutting process, it is necessary to cut not only the bottom surface side cutting but also a standing wall surface having an inclined surface of 90 ° due to processing shape restrictions. When cutting the standing wall surface in this way, 90 ° or more of the circular cutting edge of the round piece tip from the bottom side cutting point to the side cutting point becomes a contact part, and the cutting force is large, and the chips Since the discharge performance is lowered, it causes an increase in wear and loss on the side surface. In particular, in the round piece chip made of a ceramic material that is effective in cutting a super heat resistant alloy, the increase in wear on the side surface is remarkable. Further, since the tip has a cylindrical shape, a sufficient clearance angle cannot be obtained. Therefore, when the wear increases, the tool main body may come into contact with the work material, which causes a processing problem.

  As a conventional technique related to the contact portion at the bottom surface and the side surface portion, for example, in Patent Document 1 described below, in the blade tip replaceable tool having a rectangular tip shape, by changing the protruding amount in the radial direction and the axial direction, A tool is disclosed that reduces the cutting resistance during cutting by changing the cutting region of the bottom surface and the side surface, and suppresses the occurrence of chatter vibration that causes wear. Patent Document 2 below discloses a tool in which a bottom cutting tip and a side cutting tip are separately arranged.

JP 2005-59174 A JP 2010-179409 A

In Patent Document 1, in a chip exchange type milling tool, an offset amount of a mounting position of a square chip is determined, and chattering and regular vibration are prevented by displacing the rotation trajectories. However, since it is premised on the displacement of the cutting point of the square tip, it cannot be applied to a milling tool using a cylindrical round piece tip having a circular cutting edge.
In other words, in the case of a cylindrical round piece insert, the offset angle on the side surface of the tip is not ensured only by offsetting in the axial direction and the radial direction, and cutting of the standing wall surface is not taken into consideration, so abnormal wear on the side surface of the tip is suppressed. The effect for is not obtained.

Also in Patent Document 2, since the cutting edge for bottom cutting and the cutting edge for side cutting are formed with a square-shaped tip, it cannot be applied to a milling tool of a round piece tip.
Therefore, the object of the present invention is to enable cutting with high efficiency even when a cylindrical round piece chip made of a ceramic material is used for rough machining with difficult-to-cut materials such as super heat-resistant alloys, and the processing shape. It is an object of the present invention to provide a tool capable of suppressing the abnormal wear of the side surface portion of the blade edge and capable of cutting with a long life even when a standing wall surface is formed due to the above restrictions.

In order to achieve this object, the milling tool of the present invention is a milling tool in which a plurality of cylindrical round piece chips are arranged at equal intervals in the circumferential direction, and the round piece tip is centered on the tool rotation axis of the milling tool. Are divided into sets of round piece chips arranged at the same circumferential angle, and for at least one set, the tip mounting angle, the distance in the radial direction of the tool from the axis center of the tool rotation axis, and the distance in the tool rotation axis direction are set. The displacement of the other set is reduced, and the contact range between the side surface of the round piece tip and the standing wall surface of the work material is reduced for the one set, and the round piece for the other set. by the contact area between the side surface of the chip and the bottom surface of the workpiece is set to be reduced, and the set of Marukoma chip for performing cutting of the bottom surface of the workpiece, the upright wall surface of the workpiece A set of round pieces for cutting It provided with a share in.

  Furthermore, in the above-described milling tool, the radial distance of the tool and the distance in the tool rotation axis direction are displaced from the center of the tool rotation axis of the chip by selecting the thickness of the circular piece chip.

  As a set of round piece chips to be attached to the above-described milling tool, a combination of round piece chips having different thicknesses was used.

  According to the present invention, it is possible to provide a cutting tool that is highly efficient and has a long life in cutting with difficult-to-cut materials such as super heat resistant alloys. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

The perspective view of the cutting state by the milling tool which has a cylindrical-shaped chip | tip. (A) is a perspective view of the shape of a chip, (b) is a top view, (c) is a side view, and (d) is an enlarged view of a dotted line portion in (c). The top view which shows the cutting state of the milling tool which has a cylindrical-shaped chip | tip. (A) is a front view of the milling tool which has the cylindrical-shaped chip | tip arrange | positioned equally, (b) is a bottom view. The figure which shows the contact state of the chip | tip in the milling tool which has a cylindrical-shaped chip | tip, and the YZ plane of a workpiece. The figure which shows the axial direction attachment angle of a cylindrical-shaped chip | tip. The figure which shows the remarkable abrasion state which arose in the wide range of the cylindrical chip | tip by arrangement | positioning shown in FIG. (A) is a front view of the milling tool which has a cylindrical-shaped chip | tip by this invention, (b) is a bottom view. The figure which shows the contact state of the chip | tip in the milling tool which has a cylindrical-shaped chip | tip by this invention, and the YZ plane of a workpiece. The figure which shows the contact state of the chip | tip and the XZ plane of a workpiece in the milling tool which has a cylindrical-shaped chip | tip by this invention. The figure which shows the abrasion state which arose on the bottom face side of the cylindrical chip | tip by this invention. The figure which shows the abrasion state which arose on the side surface side of the cylindrical-shaped chip | tip by this invention. The enlarged view of FIG. The bottom view of the milling tool which has the cylindrical-shaped chip | tip of the other Example by this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, cutting with a milling tool using a cylindrical round piece chip, which is a premise of the present invention, will be described.
FIG. 1 is a perspective view of a state in which an L-shaped work material having a standing wall surface is being cut using a milling tool having a round piece chip.
In FIG. 1, 1 is a milling tool for cutting, and 2 is a work material. The milling tool 1 includes a tool main body 1a and a round piece chip 3 attached to the tip of the tool main body 1a.

2A and 2B show the detailed shape of the chip 3. FIG. 2A is a perspective view, FIG. 2B is a top view, FIG. 2C is a side view, and FIG. 2D is a dotted line portion in FIG. FIG.
The tip 3 is a circular piece tip having a cylindrical shape with a diameter D and a thickness t. As shown in FIG. 2A, the rake face 3a, the flank face 3b, and the boundary between the rake face 3a and the flank face 3b. Has a chamfered portion 3c. The chamfered portion 3c is an inclined surface having a chamfering width cf and a chamfering angle θ with respect to the rake surface 3a. In general, the chamfering angle θ of the chip 3 is about θ <30 °, and the chamfering width cf is cf ≦ 0.2 mm.

The tip 3 is fixed to the tool main body 1a with a stopper, a screw or the like not shown. As shown in FIG. 1, the milling tool 1 rotates about a tool rotation axis 1 b in a rotation direction 1 c, and the work material 2 is moved by moving the milling tool 1 in the direction of arrow A in the rotation state. The bottom surface 2b and the standing wall surface 2a are cut. The chips 3 are arranged at four positions in the circumferential direction with respect to the tool body 1 a and are attached so that the rake face 3 a is in the front direction with respect to the rotation direction of the milling tool 1. By cutting with the milling tool 1, a standing wall surface 2 a and a bottom surface 2 b having a height H are formed on the work material 2.
FIG. 3 shows the cutting state of FIG. 1 from the direction of the arrow B and the direction of the arrow C, (a) is a front view in the B direction, (b) is a bottom view in the direction of the arrow C, and the milling tool 1 is Then, while maintaining the counterclockwise rotational motion 1c shown in FIG. 3 (b), it goes straight in the direction of arrow A to remove the bottom surface 2b of the work material 2.

At this time, prior to the movement of the milling tool 1 in the arrow direction A, the work material 2 is displaced by a distance d in the Z-axis direction with respect to the work material 2 so as to cut the work material 2 by a depth d in the Z direction. Remove. By repeating this operation, the vertical wall surface 2a and the bottom surface 2b having a height H are cut.
In FIG. 3B, 1d shows a curved locus drawn by the tip of the chip 3.
The tip 3 moves along a curved locus (1d) on the bottom surface 2a of the workpiece 2 along with the rotational motion 1c of the milling tool 1 and the linear movement in the direction of arrow A, and exists on the locus of the curved locus 1d. The work material 2 to be cut is cut. Here, the curved locus 1d is a curved line drawn on the bottom surface 2b of the work material 2 at a pitch of the feed amount fz determined by the moving speed in the arrow A direction and the rotational speed of the rotation 1c.

Here, the problem in the case of performing the cutting shown in FIGS. 1 and 2 using the milling tool 1 in the case where the circular piece chips are evenly arranged will be described with reference to FIGS. 4A and 4B show a milling tool in which circular chip tips are arranged with the height in the Z direction, the radial position with respect to the rotation axis, and the mounting angle evenly arranged. FIG. 4A is a front view, and FIG. 4B is a bottom view. is there.
The milling tool 1 is mounted such that the tip 3 is constant in the Z direction in the axial direction of the tool body 1. Further, as shown in FIG. 4B, the respective chips 3 are arranged at the same distance R with respect to the rotating shaft 1b. Further, in FIG. 4B, when the inclination in the tool radial direction on the rake face 3a is a radial mounting angle α, α in all the chips 3 is also set to be the same.

  Here, FIG. 6 is an enlarged view of the dotted line portion shown in FIG. 3A as seen from the Y direction (see FIG. 1). Assuming that the inclination of the tip 3 with respect to the axial direction of the milling tool 1 is the axial mounting angle β, the axial mounting angle β is the same for all the tips 3. That is, the radial mounting angle α (see FIG. 4) and the axial mounting angle β are the same for all the chips 3. This is because, in the milling tool 1 shown in FIG. 4, the radial mounting angle α and the axial mounting angle β are designed on the assumption that the bottom surface 2b of the work material 2 is cut, and the standing wall 2a is removed. This is because it is not considered.

FIG. 5 shows the cutting edge contact portion of the workpiece 2 and the tip 3 indicated by the dotted line in FIG. 3C when the cutting shown in FIGS. 1 and 3 is performed using the milling tool 1 shown in FIG. It is an enlarged view of the ZY plane in FIG.
In FIG. 5, when the tip 3 cuts the standing wall 2 a of the work material 2, the portion of the outer peripheral surface of the tip 3 in the range indicated by the arc EF comes into contact with the work material 2. In the chip 3, the circumference of the arc EF is not less than ¼ of the circumference, and the chip 3 is cut in a state where a wide range of parts are in contact with each other at the outer periphery of the chip 3. As shown in the perspective view, a remarkable wear region 3d is generated on the side surface 3b. In particular, the amount of wear at the contact portion E that is the side surface of the tip 3 is increased.

  In the case of the above-described milling tool 1, since all the chips 3 are attached to the tool body 1 in the same arrangement, the contact state with the standing wall 2a is the same for all the chips, and similar wear occurs. . As a result, the contact between the side surface portion of the tool body 1 and the work material 2 occurs due to the retraction of the cutting edge of the tip 3 near the contact portion on the side surface side, making it difficult to continue cutting. In particular, in the case of the tip 3 having a cylindrical shape, the radial mounting angle α and the axial mounting angle β shown in FIGS. 4B and 6 are set with emphasis on removing the bottom surface portion 2 b of the work material 2. Therefore, when the standing wall surface 2a is in contact, wear on the side surface becomes significant.

[Example 1]
Next, an example of the milling tool according to the present invention will be described with reference to FIG. FIG. 8 shows a front view and a bottom view of the milling tool 1 according to the present invention, where (a) is a front view and (b) is a bottom view.
The milling tool 1 of the present embodiment is a tip 3 and a tip 4 that are different from each other in the diametrical position and the axial height position from the central axis 1b of the tool body 1a. They are arranged in pairs in the diameter direction. 8B, the chip 3 is disposed such that the radial mounting angle of the chip 3 is α1 and the radial mounting angle of the chip 4 is α2. Further, in the axial mounting angle, the chip 3 is disposed such that the axial mounting angle of the chip 3 is β1 and the chip 4 is axially mounted.

First, a method for setting α1 and β1 will be described with reference to FIG. As shown in FIG. 9, the tip 3 cuts the bottom surface portion 2 b with respect to the work material 2. Similarly, the tip 4 cuts the standing wall surface 2a. Here, when the radius of the locus of the circular arc drawn by the tip of the cutting edge of the milling tool 1 is R, in order for the tip 3 to cut the work material 2, the following three relational expressions must be geometrically satisfied. is necessary.
α1> 0 °
cos α1> D / (2R)
0 ° <β1 <90 °

A method for setting appropriate values of α1 and β1 will be described with reference to FIGS. That is, the cutting experiment as shown in FIG. 1 is performed by changing the radial mounting angle α and the axial mounting angle β. In addition, since the tip 3 is attached on the premise that the bottom surface portion 2b of the work material 2 is cut, a distance is set so that the tip 3 and the standing wall surface 2a of the work material 2 do not come into contact during the experiment, Only the bottom surface portion 2b is cut.
At this time, as shown in FIG. 11, the wear region 3 d is generated on the side surface 3 b of the chip 3. In the experiment, the work material 2 is cut, and the values α and β that reduce the width of the wear region 3d are set to the radial mounting angle α1 and the axial mounting angle β1 of the tip 3, respectively. As the setting range, 6 ° <α1 <30 ° and 0 ° <β1 <20 ° are appropriate. In this embodiment, α1 = 12 ° and β1 = 6 °.

Next, a setting method for α2 and β2 will be described with reference to FIGS. As shown in FIG. 9, the tip 4 is positioned at a distance of ΔR from the center of the tool rotation shaft 1 a in the radial direction of the tool with respect to the tip 3. Will be cut. Here, when the thickness of the tip 4 is t and the radius of the arc locus drawn by the tip of the milling tool 1 is R, the standing wall surface 2a of the work material 2 and the flank 4b of the tip 4 do not interfere with each other. Needs to satisfy the following three relational expressions geometrically.
sin α2> t / 2 (R + ΔR)
cos α2> D / 2 (R + ΔR)
0 ° <β2 <90 °

A method of setting appropriate values of α2 and β2 will be described with reference to FIG. That is, the cutting experiment as shown in FIG. 1 is performed by changing the radial mounting angle α and the axial mounting angle β. In addition, since the tip 3 is attached on the premise that the bottom surface portion 2b of the work material 2 is cut, a distance is set so that the tip 3 and the standing wall surface 2a of the work material 2 do not come into contact during the experiment, Only the bottom surface portion 2b is cut. At this time, as shown in FIG. 12, the wear region 4d is generated on the side surface 4b of the chip 4.
In the experiment, a certain amount of the work material 2 is cut and removed, and α and β when the width of the wear region 4d is reduced are set to the radial mounting angle α2 and the axial mounting angle β2 of the tip 4, respectively. As the setting ranges, 10 ° <α2 <45 ° and 0 ° <β2 <30 ° are appropriate. In this embodiment, α2 = 7 ° and β2 = 12 °.

FIG. 9 shows the cutting edge contact portion between the workpiece 2 and the chips 3 and 4 indicated by the dotted line in FIG. 3C when the cutting shown in FIGS. 1 and 2 is performed using the milling tool 1 of the present embodiment. It is an enlarged view of the ZY plane in FIG. The tip 4 is separated from the tip 3 by a distance ΔR in the radial direction of the tool from the center of the tool rotation axis 1a, and a distance away from the bottom surface 2a of the work material 2 by ΔZ in the tool rotation axis direction. It is arranged in.
In this embodiment, both the tip 3 and the tip 4 have a cylindrical shape with the same diameter D and thickness t, and the mounting angles, ΔR, ΔZ of each tip are 3 on the tip mounting surface of the milling tool 1 body. By designing the dimensional position, it is set to a desired value.

  Thus, during cutting, the cutting edge of the tip 3 is preferentially in the range of E′-F ′ for the bottom surface 2b of the work material 2, and the cutting edge of the tip 4 is preferentially in the range of GE ′ for the standing wall 2a. Can be removed by touching. For this reason, contact with the standing wall 2a does not occur in the chip 3, and contact with the bottom surface 2b does not occur with respect to the chip 4, and each contact range can be greatly reduced, and generation of wear is suppressed. Is possible. That is, the chip 3 can be individually assigned as the bottom surface cutting and the chip 4 as the standing wall surface cutting chip.

FIG. 10 shows the cutting edge 2 of the work piece 2 and the tips 3 and 4 shown by the dotted line in FIG. 3 (a) at the time of cutting shown in FIGS. It is an enlarged view of a ZX plane.
When the milling tool is moved in the direction of the arrow A to advance the cutting process, the tip 4 is arranged in the tool body 1 so as to be a distance away from the tip 3 by ΔZ in the tool rotation axis direction. The cutting edge of the tip 4 can be preferentially brought into contact with and removed from the bottom surface 2b of the work material 2 within the range of J-I, and the cutting edge of the tip 3 can be preferentially brought into contact with and removed within the range of I-K. The occurrence of wear can be suppressed by limiting the contact range of each blade edge.

  As a result, as shown in FIG. 11 for the tip 3 and FIG. 12 for the tip 4, the wear region 3d can be greatly reduced. Here, a method of calculating ΔR and ΔZ will be described below. An enlarged view of FIG. 9 is shown in FIG. The center point on the rake face of the chip 3 is P, and the center point on the rake face 4a of the chip 4 is Q. From FIG. 11, the angle φ1 formed by the contact arc E′F ′ between the tip 3 and the work material 2 around the point P is defined as the cutting angle of the tip 3. Similarly, an angle φ2 formed by the contact arc E′G between the tip 4 and the work material 2 around the point Q is defined as a cutting angle of the tip 4.

Here, taking the YZ coordinate system with the point F ′ in FIG. 13 as the origin, the coordinates (Y, Z) of E ′ are as follows when the rake face diameters of the chips 3 and 4 are both D:
Y = (D / 2) × sin φ1, Z = (D / 2) × (1-cos φ1)
Can be approximated.
Further, the coordinates (Y, Z) of E ′ can be calculated as follows using the cutting angle φ2 of the chip 4.
Y = ΔR + (D / 2) × sin (90−φ2)
Z = ΔZ + (D / 2) × {1-cos (90−φ2)}
Therefore,
ΔR + (D / 2) × sin (90−φ2) = (D / 2) × sinφ1 (1)
ΔZ + (D / 2) × {1-cos (90−φ2)} = (D / 2) × (1-cosφ1) (2)

Therefore, when the contact arc of the chips 3 and 4 is set to a desired value, ΔR can be designed from the equation (1) and ΔZ from the equation (2).
Here, considering the reduction of the contact arcs in the chips 3 and 4, it is desirable that φ1 and φ2 be at least 2/3 or less of the contact arc EF shown in FIG.
0 <φ1, φ2 <60 ° (3)
From the expressions (1), (2), and (3), ΔR and ΔZ are in the following ranges.
0 <ΔR, ΔZ <0.18 × D

Hereinafter, specific examples of the present invention will be described. The milling tool 1 according to the present invention is most effective in cutting that causes significant tool wear when machining difficult-to-cut materials such as heat-resistant alloys. In the heat-resistant alloy processing tool, a ceramic tool was applied as the material of the chip 3 and the chip 4 in consideration of heat resistance during high-efficiency processing. As the diameter D of the chips 3 and 4, D = 12.7 mm was selected. From a preliminary experiment with a shape in which the standing wall surface 2a is not formed on the work material 2, it was found that the appropriate range of the cut angle is 50 ° or less. Therefore, calculation is performed with φ1 = φ2 = 50 °, and ΔR = ΔZ = 0.062D is obtained.
In this case, since a chip of D = 12.7 mm is selected as the diameter of the chip 3 and the chip 4, ΔR and ΔZ in this case can be calculated as ΔR = ΔZ = 0.79 mm.

[Example 2]
As another embodiment of the present invention, the thickness t of the tip 4 is changed and attached to the main body of the milling tool 1.
FIG. 14 shows a bottom view of this embodiment, and is a bottom view showing the milling tool 1 from the same direction as FIG. 8B used in the description of the first embodiment. In FIG. 14, a chip having a chip thickness t2 is disposed on the chip 4, and the radial mounting angle of the chip 3 is α1, and the axial mounting angle is β1.
α1 and β1 are set in the same manner as in the first embodiment.

As described with reference to FIG. 9, the tip 4 is positioned at a distance of ΔR from the center of the tool rotating shaft 1a in the radial direction of the tool by cutting the standing wall surface 2a of the work material 2 with respect to the tip 3. Will be. Here, when the thickness of the tip 4 is t2, and the radius of the arc locus drawn by the tip of the milling tool 1 is R, the standing wall surface 2a of the work material 2 and the flank 4b of the tip 4 do not interfere with each other. Needs to satisfy the following three relational expressions geometrically.
sin α2> t2 / 2 (R + ΔR)
cos α2> D / 2 (R + ΔR)
0 ° <β2 <90 °
The appropriate values of α2 and β2 are set in the same manner as in the first embodiment.

Since the tip 4 has a cylindrical shape, the radial mounting angle and the radial clearance angle have the same relationship. The smaller the clearance angle, the higher the cutting edge strength and the higher the wear resistance and chipping properties. However, because of the above relations, the clearance angle also increases when the tip thickness is large.
Therefore, in this embodiment, the contact range of the tip 4 is limited to the standing wall surface 2a of the work material 2 and the contact on the bottom side is greatly reduced, so that the cutting load of the tip 4 can be reduced. As a result, the thickness t2 of the tip 4 can be reduced and the clearance angle of the tip 4 can be reduced, so that the cutting edge strength can be increased and the milling tool 1 having high wear resistance can be configured.

Further, the degree of freedom in setting the radial mounting angle α2 is improved, so that the mounting angles of the tip 3 and the tip 4 are suitable for cutting the standing wall surface 2a side and the bottom surface 2b side of the work material 2, respectively. Therefore, it is possible to construct a tool having excellent wear resistance and long life.
For example, in the conventional milling tool 1, when the thickness of the tip 3 is 8 mm and the revolution radius of the outermost peripheral part of the tool is 25 mm, the radial mounting angle α must be set to 9.2 ° or more. In this embodiment, ΔR in FIG. 9 is set to 0.5 mm, and the thickness t2 of the tip 4 is set to 5 mm, so that the radial mounting angle of the tip 4 can be set to 6 °, and the cutting edge strength is excellent. A milling tool 1 can be constructed.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, as a method that is most effective, a ceramic material tool suitable for cutting a super heat resistant alloy has been described, but the material of the tool is not limited and a cemented carbide material may be used. In addition, the material of the work material is effective even if it is not a super heat-resistant alloy, and the same effect can be obtained by processing ordinary steel material, stainless steel material or high hardness material.

  In the above-described embodiment, four circular circular piece chips are provided at 90 ° intervals in the circumferential direction, divided into two sets facing each other on the diameter, and one set of chips 3 is used for bottom cutting, and the other set. However, for example, when six cylindrical round piece chips are provided at intervals of 60 °, they may be assigned to two sets at intervals of 120 °. Further, in the case of a milling tool in which a large number of round piece chips are arranged at the same interval in the circumferential direction, the number of cylindrical round piece chips arranged at the same circumferential angle is set to three or more, and at least one of the sets is Various modifications are possible, such as a set of round piece chips for cutting the bottom surface of the work material or a set of round piece chips for cutting the standing wall surface of the work material.

  As described above, according to the present invention, cutting can be performed with high efficiency by simply displacing the tip mounting angle, the distance in the tool radial direction from the center of the tool rotation axis, and the distance in the tool rotation axis direction. Furthermore, even when standing wall surfaces are formed, abnormal wear on the side surface of the blade edge is suppressed, enabling long-life cutting, especially for roughing with difficult-to-cut materials such as super heat-resistant alloys. Expected to be widely adopted.

DESCRIPTION OF SYMBOLS 1 ... Milling tool 1a ... Tool body 1b ... Tool rotation axis 1c ... Tool rotation direction 1d ... Tool locus 2 ... Work material 2a ... Standing wall surface 2b of work material ... Bottom surface part 3 of work material, 4 ... Cylindrical chip 3a ... Rake face 3b of chip 3 ... Tip 3 flank 3c ... Chamfered part of chip 3

Claims (3)

In a milling tool in which a plurality of cylindrical round piece chips are arranged at equal intervals in the circumferential direction,
The round piece chips are divided into sets of round piece chips arranged at the same circumferential angle around the tool rotation axis of the milling tool,
For at least one set, the chip mounting angle, the distance from the axial center of the radial distance and the tool rotation axis of the tool of the tool rotation axis, is displaced relative to the other set, for the one set of, the round The contact range between the side surface of the piece chip and the standing wall surface of the work material is reduced, and the contact range between the side surface of the round piece chip and the bottom surface of the work material is reduced for the other set. By setting to
The milling tool to a set of Marukoma chip for cutting the bottom of the workpiece, characterized in that the provided shared by a set of Marukoma chip for cutting the upright wall surface of the workpiece. By selecting the thickness of the round piece chip, according to claim 1, characterized in that the distance from the axial center of the tool rotation axis of the radial distance and the tool rotation axis of the tool of the chip is displaced Milling tools. A round piece chip set which is a set of round piece chips to be attached to the milling tool according to claim 2 and which is a combination of round piece chips having different thicknesses.

Images