JP2009274173A - Profile rotary cutting tool, grooving apparatus, and grooving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform cutting at the optimum cutting speed according to a cutting edge diameter of a formed rotary cutting tool. <P>SOLUTION: The formed rotary cutting tool comprises a shank part 1 and a cutting part 2 connected to each other in series along an axis 10, wherein: the cutting part 2 has a cutting edge formed thereon so as to rotate around the axis 10; the cutting edge has a plurality of projecting cutting parts 7 formed to protrude in a cutting edge diameter direction perpendicular to the axis 10, and recessed cutting parts 9 formed between mutually adjacent projecting cutting parts 7 so as to be smaller in cutting edge diameter than the projecting cutting parts 7; and the maximum cutting edge diameter of each of the plurality of projecting cutting parts 7 becomes gradually smaller toward the distal end portion of the cutting part 2 and also the cutting edge diameter of each of the plurality of recessed cutting parts 9 becomes smaller toward the distal end portion of the cutting part 2. The plurality of projecting cutting parts 7 and the plurality of recessed cutting parts 9 are composed of at least two types of materials different in wear resistance, wherein, when their maximum cutting edge diameters are mutually compared, the one having a greater maximum cutting edge diameter is not lower in wear resistance than the one having a smaller maximum cutting edge diameter. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a total-type rotary cutting tool, a groove cutting apparatus using the same, and a groove cutting method.

  As a structure for attaching the turbine impeller to the turbine shaft, the blades of the turbine impeller in which male grooves are formed in a large number of cross-sectional Christmas tree-shaped tree grooves (female grooves) formed on the outer periphery of the turbine shaft. Some are fitted one by one.

  The tree groove (female groove) formed in the outer peripheral portion of the turbine shaft is symmetrical with respect to the groove center as in, for example, Patent Document 1, and in the groove depth direction like an inverted Christmas tree. The groove width is formed so as to be gradually reduced while increasing or decreasing. Here, the groove depth direction is the radial direction of the turbine shaft, and the groove width direction is a direction substantially perpendicular to the groove depth direction.

  As a conventional rotary cutting tool used for processing a tree groove, for example, a general rotary cutting tool integrally provided with a shank portion and a blade portion is used. The blade portion has, for example, a conical shape, and a plurality of constricted portions are formed. That is, the blade portion has a shape like a Christmas tree having a protruding portion and a constricted portion. A cutting edge is formed on the blade portion. The cutting blades include straight blades, right-handed blades with excellent cutting performance, left-handed blades, and the like. Usually, about 2 to 4 of these blades are provided.

As such a general-purpose rotary tool, for example, as disclosed in Patent Document 1, an example in which the rake angle of the cutting edge is improved is known. Patent Document 2 discloses a study on a twist angle, and Patent Document 3 discloses an example in which a clearance angle is studied. In addition, as disclosed in Patent Document 4, an example in which a cutting edge ridge is studied is also known.
JP 2001-072210 A JP 2007-175830 A Japanese Patent Laid-Open No. 11-245112 JP 2001-2112711 A

  When the female groove is cut using the conventional general-purpose rotary tool, the groove width that increases or decreases in the groove depth direction of the female groove is cut at the same tool rotation speed. A portion having a wide groove width is cut at the above-described protruding portion, and a portion having a small groove width is cut at the constricted portion. In this case, the above-described general cutting rotary tool has a large difference in cutting speed between the portion where the cutting edge protrudes perpendicularly to the axis and the constricted portion, so the difference in cutting speed becomes large. That is, the cutting speed of the portion where the groove width of the female groove is small is lower than that of the portion where the groove width is wide.

  For example, when the rotation speed of the tool is set so that the cutting speed is optimal for a cutting edge that cuts a part having the smallest groove width, the cutting speed is increased for the cutting edge that cuts a part having the largest groove width. In some cases, the region where the groove width is maximum may exceed the applicable cutting speed range of the tool grade.

  On the other hand, when the tool rotation speed is set so as to obtain an optimum cutting speed for the cutting edge that cuts the portion having the maximum groove width, the cutting speed is reduced at the portion having the minimum groove width. In this case, there is a possibility that the tool material type becomes smaller than the applicable cutting speed range.

  In addition, when cutting is performed at a tool rotation speed at which the optimum width between the minimum groove width and the maximum groove width is cut, if the difference between the minimum groove width and the maximum groove width is too large, the minimum groove width and Each maximum groove width may exceed the applicable range.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to make it possible to perform cutting at an optimum cutting speed in accordance with the cutting edge diameter of the total-type rotary cutting tool. .

  In order to achieve the above-mentioned object, the general-purpose rotary cutting tool according to the present invention is a general-purpose rotary cutting tool in which a shank portion and a blade portion are connected along an axial center. A plurality of convex cutting edge portions formed so as to project in the radial direction of the cutting edge perpendicular to the axis, and arranged in the axial direction; A concave cutting edge portion formed between the convex cutting edge portions adjacent to each other in the axial direction and having a cutting edge diameter smaller than the convex cutting edge portions, and The maximum cutting edge diameter of each of the plurality of convex cutting edges gradually decreases toward the tip of the cutting edge, and the maximum cutting edge diameter of each of the plurality of concave cutting edges is the tip of the cutting edge. It is formed to become gradually smaller toward The plurality of convex cutting edge portions and the plurality of concave cutting edge portions are made of at least two kinds of materials having different wear resistance, and the maximum of each of the plurality of convex cutting edge portions and the plurality of concave cutting edge portions. When the cutting edge diameters are compared with each other, the wear resistance is not low when the maximum cutting edge diameter is large compared to the small cutting edge diameter.

  Moreover, the groove cutting apparatus according to the present invention is a groove cutting apparatus that forms a Christmas tree-shaped groove in a cross section for fitting the blade leg of the turbine blade to the outer periphery of the turbine shaft by a combination of a female groove and a male groove. And the cross-sectional shape of the female groove is symmetrical with respect to the center line from the groove opening toward the groove bottom, one each between a plurality of wide portions spreading on both sides and the wide portions adjacent to each other. Each of the widened portion and the constricted portion is formed so that the width in the groove width direction increases as it is closer to the groove opening. A cutting tool is formed so as to rotate around the axis, and the cutting edge is formed as follows: Stretched in the radial direction of the blade edge perpendicular to the axis Are formed between the plurality of convex cutting edge portions arranged in the axial direction and the convex cutting edge portions adjacent to each other in the axial direction, and from these convex cutting edge portions. A concave cutting edge portion formed so as to reduce the cutting edge diameter, and the maximum cutting edge diameter of each of the plurality of convex cutting edge portions gradually decreases toward the tip of the blade portion, The maximum cutting edge diameter of each of the plurality of concave cutting blade portions is formed so as to gradually decrease toward the tip of the blade portion, and the plurality of convex cutting blade portions and the plurality of concave cutting blade portions. Is composed of at least two types of materials having different wear resistance, and the maximum cutting edge diameter is large when the maximum cutting edge diameters of the plurality of convex cutting edge portions and the plurality of concave cutting edge portions are compared with each other. Compared to small things Abrasion resistance is not lower, and wherein.

  Further, the groove cutting method according to the present invention includes a cross-sectional Christmas tree-like groove for fitting a blade tip of a turbine blade on the outer periphery of a turbine shaft by a combination of a female groove and a male groove, using a rotary rotary cutting tool. In the groove cutting method to be formed, the cross-sectional shape of the female groove is symmetrical with respect to the center line from the groove opening to the groove bottom, and a plurality of wide portions spreading on both sides and the wide adjacent to each other. Each of the wide portions and the constricted portion are formed so that the width in the groove width direction increases as they are closer to the groove opening, The groove cutting method is a method of cutting by rotating the cutting edge around an axis parallel to the center line and gradually moving the cutting edge in a direction perpendicular to the axis, and cutting the wide portion. Part machining process The constricted portion machining step for cutting the constricted portion is performed in parallel, and the wide portion machining step and the constricted portion machining step are performed with a cutting edge that cuts a large groove width compared to a cutting edge that cuts a small groove width. It is characterized by cutting with a material that is not low in wear resistance.

  According to the present invention, it is possible to perform cutting at an optimum cutting speed according to the cutting edge diameter of the total-type rotary cutting tool.

  Hereinafter, an embodiment of a general-purpose rotary cutting tool according to the present invention will be described with reference to the drawings.

[First Embodiment]
A first embodiment of a total-type rotary cutting tool according to the present invention will be described with reference to FIGS. First, the configuration of the total rotary cutting tool of the present embodiment will be described with reference to FIG. FIG. 1 is a schematic front view of a total-type rotary cutting tool used in the groove cutting apparatus according to the present embodiment. The total rotary cutting tool has a shank portion 1 and a blade portion 2 along an axis 10. These are connected and integrated along the axial center 10. In addition, in FIG. 1, the blade part 2 has shown only the cutting edge and the chip discharge groove | channel 3, and has shown only the outline other than that.

  The shank portion 1 is formed so as to be attachable to a main shaft of a cutting machine (not shown) such as a milling machine or a machining center. It can also be stored in a tool magazine of a machining center.

  The blade part 2 is formed of hardened steel or the like. A cutting edge formed of cemented carbide or high speed steel is brazed to the blade portion 2. The cutting edge cuts the object to be cut while rotating around the axis 10. Further, a chip discharge groove 3 is formed along the axis 10 so as to be adjacent to the cutting edge, for example. Chips generated when cutting are discharged from the chip discharge groove 3. The chip discharge groove 3 enables efficient discharge to the outside so that chips do not get tangled at the cutting point of the cutting edge.

  The cutting edges are four convex cutting edge portions 7 so as to protrude in the radial direction of the cutting edge, that is, a first convex cutting edge portion 7a, a second convex cutting edge portion 7b, a third convex cutting edge portion 7c, And the 4th convex cutting edge part 7d is formed. Here, the cutting edge radial direction means a direction perpendicular to the axis 10.

  A tip cutting edge portion 8 is formed on the tip of the blade portion 2, that is, on the tip side of the fourth convex cutting edge portion 7d. The contour of the tip cutting edge portion 8 may be smoothly connected to the fourth convex cutting edge portion 7d with the tip having a substantially arc shape.

  Furthermore, between the 1st convex cutting edge part 7a and the 2nd convex cutting edge part 7b, the 1st concave cutting edge part 9a whose edge diameter is smaller than these cutting edge parts 7a and 7b is formed. . The first concave cutting edge portion 9a may be smoothly connected to the first convex cutting edge portion 7a and the second convex cutting edge portion 7b. Between the 2nd convex cutting edge part 7b and the 3rd convex cutting edge part 7c, the 2nd concave cutting edge part 9b whose blade edge diameter is smaller than these cutting edge parts 7b and 7c is formed. Similarly, a third concave cutting edge portion 9c is formed between the third convex cutting edge portion 7c and the fourth convex cutting edge portion 7d.

  When the ridgelines of the first to fourth convex cutting edge portions 7a, 7b, 7c, 7d, the tip cutting edge portion 8, and the first to third concave cutting edge portions 9a, 9b, 9c are smoothly connected In addition, these cutting edge portions form one cutting edge. The cutting blade includes a straight blade in which the contour of the cutting edge ridge line is formed in one plane along the axis 10, a right-handed blade formed so that the contour of the ridge line is twisted around the axis 10, and There is a left twist blade. In FIG. 1, one cutting edge is shown, but 2 to 4 cutting edges may be formed around the axis 10.

  The blade tip diameters of the first to fourth convex cutting edge portions 7a, 7b, 7c, and 7d gradually become smaller toward the tip of the blade portion 2, and the first to third concave cutting edge portions 9a, Each of the blade diameters 9b and 9c is formed so as to gradually become smaller toward the tip of the blade portion 2. That is, the convex cutting edge part 7 has a cutting edge diameter in the order of the first convex cutting edge part 7a, the second convex cutting edge part 7b, the third convex cutting edge part 7c, and the fourth convex cutting edge part 7d. Get smaller. Similarly, the concave cutting edge portion 9 has a cutting edge diameter that decreases in the order of the first concave cutting blade portion 9a, the second concave cutting blade portion 9b, and the third concave cutting blade portion 9c. That is, the blade portion 2 has a shape like a Christmas tree as a whole.

  The cutting edge diameter at this time is, for example, from the axis 10 to the cutting edge in each of the first to fourth convex cutting edge portions 7a, 7b, 7c, 7d and the first to third concave cutting edge portions 9a, 9b, 9c. The maximum cutting edge diameter with the largest distance is used.

  The maximum cutting edge diameter of each cutting edge part of this embodiment is the first convex cutting edge part 7a, the second convex cutting edge part 7b, the first concave cutting edge part 9a, the third convex cutting edge part 7c, The second concave cutting edge portion 9b, the fourth convex cutting edge portion 7d, and the third concave cutting edge portion 9c become smaller in this order.

  The first to fourth convex cutting edge portions 7a, 7b, 7c, 7d and the first to third concave cutting edge portions 9a, 9b, 9c are composed of at least two types of tool materials having different wear resistances. Yes. Below, the procedure which selects the tool material type of a cutting edge according to a blade edge diameter is demonstrated using the example shown in FIG.

  FIG. 2 is a graph showing the relationship between the cutting speed and the tool life time, and illustrates four types of tool materials (A, B, C, and D). The tool material type at this time is not limited to the material type of the base material of the cutting edge, such as high speed steel, cemented carbide, and sintered diamond, but covers the surface of the cutting edge, for example, DLC (diamond like carbon), etc. The coating material etc. are also included.

  The cutting speed range S shown in FIG. 2 indicates the cutting speed range that can be cut in the tool material type D. When cutting is performed with the tool material type D set to a cutting speed outside this range S, chipping and rapid tool wear occur, and cutting becomes impossible.

  The optimum cutting speed of the tool material type A is speed V1, and the tool life time when cutting at this speed V1 is defined as time T. Here, the tool life time means, for example, a time when it is determined that a tool needs to be replaced. Similarly, optimum cutting speeds for tool grades B, C, and D are defined as speeds V2, V3, and V4, respectively. In this example, the optimum cutting speed decreases in the order of the tool material types A, B, C, and D. That is, the wear resistance of these tool grades decreases in the order of A, B, C, and D.

  Further, in this example, the tool life of each tool material type when cutting is performed at the optimum cutting speeds V1, V2, V3, and V4 of each tool material type in each of the tool material types A, B, C, and D. All times are almost the same time (time T).

  For example, in the total-type rotary cutting tool shown in FIG. 1, the cutting speed is maximized at the first convex cutting edge portion 7a having the maximum cutting edge diameter. For the first convex cutting edge portion 7a, for example, a tool material type A having an optimum cutting speed is used. At this time, the rotation speed of the tool is calculated in accordance with the optimum cutting speed (speed V1) in the tool material type A. This rotational speed is defined as a rotational speed R1.

  Subsequently, the rotation speed of the tool is set as the rotation speed R1, and the cutting speed at the second convex cutting edge portion 7b is calculated. At this time, a tool material type is selected such that the calculated cutting speed is an optimum cutting speed. The cutting speed of the second convex cutting edge portion 7b is lower than that of the first convex cutting edge portion 7a under the same rotation speed, for example, the rotation speed R1. Therefore, it is preferable to select a tool material type, for example, a tool material type B, such that a cutting speed smaller than the optimum cutting speed V1 of the first convex cutting edge portion 7a becomes the optimum cutting speed.

  Similarly, for example, the tool material type C may be selected for the third convex cutting edge portion 7c, and the tool material type D may be selected for the fourth convex cutting edge portion 7d. At this time, since the cutting edge diameter of the first concave cutting edge portion 9a is substantially the same as that of the third convex cutting edge portion 7c, the tool material type C may be selected for the first concave cutting edge portion 9a.

  In addition, the edge diameter of the second concave cutting edge portion 9b is smaller than the third convex cutting edge portion 7c and larger than the fourth convex cutting edge portion 7d. In this case, the tool material type C or the tool material type D may be selected.

  The third concave cutting edge portion 9c may be selected as the tool material type D, assuming that the difference in the cutting edge diameter from the fourth convex cutting edge portion 7c is small. Alternatively, a tool material type having lower wear resistance than the tool material type D may be selected.

  As can be seen from the above description, the maximum cutting edge diameters of the first to fourth convex cutting edge portions 7a, 7b, 7c, 7d and the first to third concave cutting edge portions 9a, 9b, 9c are compared with each other. In this case, the tool material type is selected so that the tool with a large maximum cutting edge diameter does not have lower wear resistance than the tool with a small maximum cutting edge diameter. Thereby, it is possible to perform cutting at an optimal cutting speed.

  Subsequently, an example of machining for cutting a groove using the above-described general rotary cutting tool will be described below.

  The overall rotary cutting tool of the present embodiment has, for example, a cross-shaped Christmas tree-like groove for fitting the blade leg of the turbine blade to the outer periphery of the turbine shaft by a combination of a female groove 30 and a male groove (not shown). It can be used for processing. The total-type rotary cutting tool shown in FIG. 1 is used for machining the female groove 30 formed on the outer periphery of the turbine shaft.

  First, the shape of the female groove 30 processed in this embodiment will be described.

  FIG. 3 is a cross-sectional view showing an example of the female groove 30 formed on the outer periphery of the turbine shaft. The cross-sectional shape of the female groove 30 is symmetrical with respect to the center line 25 from the groove opening 23 toward the groove bottom 24, and four wide portions 21 spreading on both sides, that is, a first wide portion 21 a and a second wide portion. 21b, a third wide portion 21c, and a fourth wide portion 21d.

  Moreover, it has the narrow part 22 formed 1 each between the wide parts 21 adjacent to each other. For example, a first constricted portion 22a is formed between the first wide portion 21a and the second wide portion 21b. Similarly, a second constricted portion 22b is formed between the second wide portion 21b and the third wide portion 21c, and a third constricted portion 22c is formed between the third wide portion 21c and the fourth wide portion 21d. Has been. Each of the wide portion 21 and the constricted portion 22 decreases in width in the groove width direction from the groove opening 23 toward the groove bottom 24.

  This female groove 30 is processed using the total-type rotary cutting tool of FIG.

  While rotating the general-purpose rotary cutting tool around the axis 10, the axial center 10 is arranged so as to be parallel to the center line 25, and the total-type rotary cutting tool is arranged in a direction perpendicular to the center line 25. Cut while moving.

  The first wide portion 21a is cut by the first convex cutting edge portion 7a. Similarly, the second wide portion 21b and the third wide portion 21c are cut by the second convex cutting edge portion 7b and the third convex cutting edge portion 7c, respectively. The fourth wide portion 21d and the groove bottom portion 24 are cut by the fourth convex cutting edge portion 7d and the tip cutting edge portion 8, respectively.

  The first constricted portion 22a is cut by the first concave cutting edge portion 9a. Similarly, the second constricted portion 22b and the third constricted portion 22c are cut by the second concave cutting edge portion 9b and the third concave cutting edge portion 9c, respectively.

  As described above, the blade portion 2 uses a different tool material type depending on the cutting edge diameter so that cutting can be performed at an optimum cutting speed according to each groove width of the female groove 30. For example, the first wide portion 21a where the cutting speed is increased and the third constricted portion 22c where the cutting speed is lower than that can be cut in parallel at the optimum cutting speed.

  Further, since the tool material type is selected so that the tool life time is substantially the same in each part of the cutting edge, the timing at which the cutting edge reaches the life is substantially the same in each part of the cutting edge. For example, the first convex cutting edge portion 7a that cuts the first wide portion 21a and the third concave cutting edge portion 9c that cuts the third constricted portion 22c are substantially the same even if they are cut at different cutting speeds. The tool life time, i.e., the replacement timing, is reached.

  That is, it is not necessary to replace a cutting edge portion that can still be cut in order to suppress cutting with a cutting edge that needs to be replaced after reaching the tool life time. Therefore, it is possible to reduce the cost for replacing the cutting edge.

  In the present embodiment, the cutting edge diameters of the convex and concave cutting edge portions 7 and 9 for cutting the groove portions such as the wide portion 21 and the constricted portion 22 of the female groove 30 are smaller than the groove width of each groove portion. It is formed as follows. In this case, for example, the female groove 30 is formed by cutting one groove shape with respect to the center line 25 shown in FIG. 3 and then cutting the other groove shape.

  As can be seen from the above description, it is possible to suppress the short life of the cutting tool, the tool chipping, and the like due to mismatch between the tool material type and the cutting speed, and to improve the machining efficiency.

[Second Embodiment]
Next, a second embodiment of the total-type rotary tool according to the present invention will be described with reference to FIG. FIG. 4 is a schematic front view of a total-type rotary cutting tool used in the groove cutting apparatus of the present embodiment. In addition, this embodiment is a modification of 1st Embodiment, Comprising: The same code | symbol is attached | subjected to the same part or similar part as 1st Embodiment, and duplication description is abbreviate | omitted.

  As shown in FIG. 4, in this embodiment, the first convex cutting edge portion 7a, the second convex cutting edge portion 7b, the third cutting convex blade portion 7c, and the first cutting edge portion of the total rotary cutting tool of FIG. Cutting blades corresponding to the four cutting convex blade portions 7d can be selectively attached and detached. These detachable cutting blade members are defined as a first detachable cutting blade member 11a, a second detachable cutting blade member 11b, a third detachable cutting blade member 11c, and a fourth detachable cutting blade member 11d, respectively. In the present embodiment, a cutting edge corresponding to the tip cutting edge portion 8 in the total rotary cutting tool of FIG. 1 is included in the fourth detachable cutting blade member 11d.

  In the base material of the blade portion 2, for example, 1 is attached to a portion where the first detachable cutting blade member 11 a, the second detachable cutting blade member 11 b, the third detachable cutting blade member 11 c, and the fourth detachable cutting blade member 11 d are disposed. A first screw hole 13a, a second screw hole 13b, a third screw hole 13c, and a fourth screw hole 13d are formed one by one. These screw holes 13a, 13b, 13c, and 13d are formed in the tool rotation direction, that is, in the circumferential direction.

  A first detachable cutting blade member 11a, a second detachable cutting blade member 11b, a third detachable cutting blade member 11c, and a fourth detachable cutting blade member are provided in each of the screw holes 13a, 13b, 13c, and 13d, for example, by a bolt 19 or the like. 11d is attached. These first to fourth detachable cutting blade members 11a, 11b, 11c, and 11d are formed of different tool material types. Therefore, similarly to the first embodiment, each of the first to fourth detachable cutting blade members 11a, 11b, 11c, and 11d can cut at an optimum cutting speed.

  Moreover, these detachable cutting blade members 11a, 11b, 11c, and 11d may be smoothly connected to the adjacent first to third concave cutting blade portions 9a, 9b, and 9c. For example, an adjustment member (not shown) such as a shim may be adjusted between the first detachable cutting blade member 11a and the base material of the blade portion 2 so that no step is generated.

  In the first embodiment, when machining of the female groove 30, if an unexpected trouble occurs and a part of the blade portion 2 of the total-type rotary cutting tool is lost, the total-type rotary cutting tool It is necessary to replace itself.

  On the other hand, by using the detachable cutting blade members 11a, 11b, 11c, and 11d for the cutting edge portion that is likely to be worn or chipped during cutting, for example, the convex cutting edge portion 7 having a relatively high cutting speed. The cutting edge can be easily replaced. Therefore, the cost can be reduced compared to replacing the entire rotary cutting tool itself. Moreover, it becomes possible to use the base material of the blade part 2 semipermanently, for example, and can reduce the cost of a tool material.

  Moreover, it may not always be optimal to try to compensate for the difference in cutting speed caused by the difference between the minimum groove width and the maximum groove width of the female groove 30 only with the tool material type. For example, even if the optimum tool material type can be selected for the first detachable cutting blade member 11a, if this optimum tool material type is expensive, the cost can be greatly increased even if the machining efficiency can be improved. It may be higher.

  On the other hand, as in this embodiment, the cutting edge portion is formed by the detachable cutting edge members 11a, 11b, 11c, and 11d, so that the process design balances the machining efficiency and the cost of the tool material type. It becomes possible to consider at the stage.

[Third Embodiment]
Next, a third embodiment of the total rotary tool according to the present invention will be described with reference to FIG. FIG. 5 is a schematic front view of a total-type rotary cutting tool used in the groove cutting apparatus of the present embodiment. The present embodiment is a modification of the first and second embodiments, and the same or similar parts as those of the embodiments are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 5, in this embodiment, the 4th convex cutting edge part 7d and the front-end | tip cutting edge part 8 can be selectively attached or detached. This detachable cutting blade member is defined as a detachable tip cutting blade member 12. In the present embodiment, the fourth convex cutting edge portion 7 d is included in the detachable tip cutting edge member 12.

  For example, one tip cutting edge screw hole 14 is formed in the direction of the axis 10 at the tip of the base material of the blade portion 2 where the detachable tip cutting edge member 12 is disposed. Although not shown, the detachable tip cutting blade member 12 is attached to the tip cutting blade screw hole 14 with a bolt or the like. The detachable tip cutting edge member 12 may be smoothly connected to the adjacent third concave cutting edge portion 9c as in the second embodiment.

  According to the present embodiment, it is possible to easily replace the detachable tip cutting edge member 12 on the tip cutting edge portion whose cutting speed is smaller than the cutting range of the tool material type. Moreover, it becomes possible to use the base material of the blade part 2 semipermanently, and the cost of a tool material can be reduced.

[Other Embodiments]
The description of the above embodiment is an example for explaining the present invention, and does not limit the invention described in the claims. Moreover, each part structure of this invention is not restricted to the said embodiment, A various deformation | transformation is possible within the technical scope as described in a claim.

  In the first embodiment, an example using four types of tool materials has been described, but the present invention is not limited to this. For example, for each of the first to fourth convex cutting edge portions 7a, 7b, 7c, 7d and the first to third concave cutting edge portions 9a, 9b, 9c, seven types of tool materials having different wear resistance are used. May be. In this case, a tool material having higher wear resistance may be used as the blade diameter is larger.

  Further, only two types of tool materials having different wear resistance may be used. In this case, it is preferable to use a tool material with higher wear resistance for the first convex cutting edge portion 7a and use a lower wear resistance for the other cutting edge portions.

  In 2nd Embodiment, although the detachable cutting edge part is made into the convex cutting edge part 7, it is not restricted to this. The concave cutting edge portion 9 may also be detachably formed.

  Further, in the above-described embodiment, an example is described in which the cutting edge diameters of the convex and concave cutting edge portions 7 and 9 that cut each groove portion of the female groove 30 are smaller than the groove width of each groove portion.

  On the other hand, for example, the total rotary cutting tool formed so that the groove width of each groove part and the respective cutting edge diameters of the convex and concave cutting edge parts 7 and 9 cutting these groove parts are substantially the same. May be used. In this case, the grooves on both sides of the center line 25 shown in FIG. 3 can be cut in parallel.

It is a schematic front view of the total type rotary cutting tool used for the groove cutting apparatus of 1st Embodiment which concerns on this invention. It is a graph which shows the relationship between the cutting speed and tool life in the tool material type used by embodiment of FIG. It is a cross-sectional shape of the female groove cut by the embodiment of FIG. It is a schematic front view of the total type rotary cutting tool used for the groove cutting apparatus of 2nd Embodiment which concerns on this invention. It is a schematic front view of the total type rotary cutting tool used for the groove cutting apparatus of 3rd Embodiment which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Shank part, 2 ... Blade part, 3 ... Chip discharge groove, 7 ... Convex cutting edge part, 7a ... 1st convex cutting edge part, 7b ... 2nd convex cutting edge part, 7c ... 3rd convexity Shape cutting edge part, 7d ... 4th convex cutting edge part, 8 ... tip cutting edge part, 9 ... concave cutting edge part, 9a ... 1st concave cutting edge part, 9b ... 2nd concave cutting edge part, 9c ... 1st 3 concave cutting edge portions, 10... Axis, 11 a... 1 detachable cutting blade member, 11 b. 2 detachable cutting blade member, 11 c. 3 detachable cutting blade member, 11 d. Tip cutting edge member, 13a ... 1st screw hole, 13b ... 2nd screw hole, 13c ... 3rd screw hole, 13d ... 4th screw hole, 14 ... Screw hole for tip cutting edge, 19 ... Bolt, 21 ... Wide part 21a ... 1st wide part, 21b ... 2nd wide part, 21c ... 3rd wide part, 21d ... 4th wide part, 22 ... Constriction part, 22a ... 1st constriction , 22b ... second neck portion, 22c ... third constriction, 23 ... groove opening, 24 ... groove bottom 25 ... center line, 30 ... female groove

Claims (5)

In the total rotary cutting tool in which the shank part and the blade part are connected along the axis,
The blade portion is formed with a cutting blade so as to rotate around the axis,
The cutting edge is
A plurality of convex cutting edge portions formed so as to project in the radial direction of the cutting edge perpendicular to the axial center, and arranged in the axial direction;
A concave cutting edge portion formed between the convex cutting edge portions adjacent to each other in the axial direction, and having a cutting edge diameter smaller than the convex cutting edge portions;
Have
The maximum cutting edge diameter of each of the plurality of convex cutting edges gradually decreases toward the tip of the cutting edge, and the maximum cutting edge diameter of each of the plurality of concave cutting edges is the tip of the cutting edge. It is formed to become gradually smaller toward
The plurality of convex cutting edge portions and the plurality of concave cutting edge portions are composed of at least two kinds of materials having different wear resistance,
When the maximum cutting edge diameter of each of the plurality of convex cutting edge portions and the plurality of concave cutting edge portions is compared with each other, the wear resistance is not low compared to the one having a large maximum cutting edge diameter,
Total type rotary cutting tool characterized by   2. The overall rotary cutting tool according to claim 1, wherein each of the convex cutting edge portion and the concave cutting edge portion is configured to be selectively detachable.   The tip cutting edge portion formed at the tip portion of the blade portion is fastened and fixed in the axial direction by a fastening member formed in the axial direction, and is selectively detachable. The total-type rotary cutting tool according to claim 1 or 2. A groove cutting device for forming a Christmas tree-shaped groove in a cross section for fitting a blade leg of a turbine blade by a combination of a female groove and a male groove on the outer periphery of a turbine shaft,
The cross-sectional shape of the female groove is symmetrical with respect to the center line from the groove opening toward the groove bottom, and is arranged one by one between a plurality of wide portions spreading on both sides and the wide portions adjacent to each other. Each of the widened portion and the constricted portion is formed so that the width in the groove width direction becomes larger as it is closer to the groove opening,
The groove cutting apparatus has a total rotary cutting tool in which a shank portion and a blade portion are connected along an axis,
The blade portion is formed with a cutting blade so as to rotate around the axis,
The cutting edge is formed so as to protrude in the radial direction of the cutting edge perpendicular to the axis, and the plurality of convex cutting edges arranged in the axial direction and the convex cutting edges adjacent to each other in the axial direction. A concave cutting edge portion formed so as to have a cutting edge diameter smaller than those convex cutting edge portions formed between the parts,
The maximum cutting edge diameter of each of the plurality of convex cutting edges gradually decreases toward the tip of the cutting edge, and the maximum cutting edge diameter of each of the plurality of concave cutting edges is the tip of the cutting edge. It is formed to become gradually smaller toward
The plurality of convex cutting edge portions and the plurality of concave cutting edge portions are composed of at least two kinds of materials having different wear resistance,
When the maximum cutting edge diameter of each of the plurality of convex cutting edge portions and the plurality of concave cutting edge portions is compared with each other, the wear resistance is not low compared to the one having a large maximum cutting edge diameter,
A groove cutting device characterized by the above. A groove cutting method for forming a cross-shaped Christmas tree-shaped groove for fitting a blade tip of a turbine blade by a combination of a female groove and a male groove on the outer periphery of the turbine shaft,
The cross-sectional shape of the female groove is symmetrical with respect to the center line from the groove opening toward the groove bottom, and is arranged one by one between a plurality of wide portions spreading on both sides and the wide portions adjacent to each other. Each of the widened portion and the constricted portion is formed so that the width in the groove width direction becomes larger as it is closer to the groove opening,
The groove cutting method is
Cutting by gradually moving the cutting edge in a direction perpendicular to the axis while rotating around the axis parallel to the center line,
A wide portion machining step for cutting the wide portion and a constricted portion machining step for cutting the constricted portion are performed in parallel.
The wide part machining step and the constricted part machining step are characterized in that the cutting edge that cuts a large groove width is cut with a wear resistance that is not lower than that of a cutting edge that cuts a small groove width. Processing method.

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