JP2010214489A - Rotary cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary cutting tool allowing partial replacement of a part of a blade part. <P>SOLUTION: This rotary cutting tool has a blade end diameter on an outer periphery of the blade part gradually reduced in size toward a distal end part in the longitudinal direction of a rotary shaft of the tool, while repeating increase and decrease, and a machining groove. The rotary cutting tool is constituted of a mandrel supporting the blade part and becoming the rotary shaft, a tool supporting member supporting the mandrel at an end part on an opposite side of a distal end part side of the blade part, and the blade part constituted of a plurality of blade part units including a distal end part unit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotary cutting tool mainly used for grooving.

The groove for attaching the blade to the rotating shaft of the turbine rotor has a complicated shape. It is symmetrical with respect to the center of the groove and is gradually narrowed while increasing or decreasing the groove width in the groove depth direction so that the Christmas tree is turned upside down. As a tool for cutting such tree-shaped grooves,
As shown in FIG. 8, there is known a rotary cutting tool, that is, a Christmas cutter, in which the cutting edge diameter of the outer peripheral cutting edge gradually increases and decreases toward the tip side of the tool in response to the change in the groove width of the tree-shaped groove. It has been. Since the Christmas cutter has a long blade portion, the resistance during cutting increases, so that a portion with a small tool diameter is particularly easily damaged. In order to solve this problem, means for reducing cutting resistance during processing has been considered. As an example, the rake angle is changed (Patent Document 1).
), And a modified clearance angle (Patent Document 2).

JP 2001-72110 A JP 2007-175830 A

However, even in the rotary cutting tools disclosed in Patent Documents 1 and 2, it is inevitable that a part of the blade portion is lost. Even if the cutting performance is deteriorated due to wear of the blade portion in a part of the tool, the tool unit must be replaced. On the other hand, since the Christmas cutter is expensive, it is disadvantageous in terms of cost to replace the tool unit due to a reduction in the cutting performance of the blade part in a part of the tool.

This invention is made | formed in view of such a situation, The objective is to provide the rotary cutting tool which can replace | exchange part of a blade part partially.

According to one aspect of the present invention, in the rotary cutting tool having a machining groove, the cutting edge diameter on the outer periphery of the blade portion gradually decreases as it increases and decreases toward the tip portion in the longitudinal direction of the rotation axis of the tool. A mandrel that supports the shaft and serves as a rotating shaft, a tool support member that supports the mandrel at an end opposite to the tip of the blade, and a plurality of blade units each including a tip unit. A rotary cutting tool is provided.

ADVANTAGE OF THE INVENTION According to this invention, the rotary cutting tool which can perform replacement | exchange of a blade part efficiently by making it the structure which can divide | segment a blade part of a tool is provided.

It is a mimetic diagram for illustrating the rotary cutting tool concerning an embodiment of the invention. It is a model exploded view for illustrating the rotary cutting tool which concerns on embodiment of this invention. It is a model exploded view for illustrating the rotary cutting tool which concerns on embodiment of this invention. It is sectional drawing for illustrating the rotary cutting tool which concerns on embodiment of this invention. It is a model exploded view for illustrating the rotary cutting tool which concerns on embodiment of this invention. It is a mimetic diagram for illustrating the rotary cutting tool concerning an embodiment of the invention. It is a mimetic diagram for illustrating the rotary cutting tool concerning an embodiment of the invention. It is a schematic diagram for illustrating a rotary cutting tool.

Hereinafter, embodiments of the present invention will be illustrated with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to the same component and detailed description is abbreviate | omitted suitably.
FIG. 1 is a schematic diagram of a rotary cutting tool according to an embodiment of the present invention, which is simplified compared to FIG. The blade part 1 fixed to the shank 2 which is a member that supports the tool can be divided at the dotted line part.

A first embodiment of the present invention will be described. FIG. 2 is a schematic exploded view in which the blade portion 1 is divided into units along the dotted line shown in FIG. The blade 1 is a tip blade 3 and a first blade that is an intermediate blade.
The intermediate blade portion 5 and the second intermediate blade portion 6 are configured with a mandrel 7 as an axis. The mandrel 7 is connected to the shank 2 and is provided so as to be concentric with the rotation axis of the tool. The outer diameter of the mandrel 7 is constant. The first intermediate blade portion 5 and the second intermediate blade portion 6 have through holes 10 and 11 provided so as to be concentric with the rotation axis of the cutting tool, that is, the mandrel 7. The through hole diameters of the through holes 10 and 11 are made constant. The mandrel 7 is passed through the through holes 10 and 11 of the first intermediate blade part 5 and the second intermediate blade part 6,
A fit with a gap between the mandrel 7 and the through holes 10 and 11, that is, a clearance fit state.

The leading edge part 3 is provided with a leading edge part side connecting part 4a. Further, the mandrel 7 is provided with a mandrel side connecting portion 4b. The mandrel 7 has a first intermediate blade portion 5, a through hole 10 in the second intermediate blade portion 6,
11, the leading edge part side connecting part 4 provided on the leading edge part 3 from the first intermediate blade part 5 side.
a and the mandrel side connection part 4b are connected. The tip blade portion side connecting portion 4a has a male screw shape and a mandrel side connecting portion 4b has a female screw shape, and is connected by screwing. The direction in which the screw is tightened matches the direction in which the tool rotates during cutting. Thus, cutting is performed in a state in which the tip blade portion 3, the first intermediate blade portion 5, and the second intermediate blade portion 6 are fixed to the shank 2 via the mandrel 7.

A second embodiment of the present invention will be described with reference to FIG. In addition to the first embodiment, a cylindrical concave-convex fit is provided between the first intermediate blade portion 5 and the second intermediate blade portion 6 and between the second intermediate blade portion 6 and the shank 2. Matching members 8a, 8b, 9a, 9b are provided. The fitting members are paired with a convex portion 9 a provided on the mating surface 11 of the first intermediate blade portion 5 and a concave portion 8 a provided on the mating surface 12 of the second intermediate blade portion 6. The convex portion 9b provided on the mating surface 13 opposite to the concave portion 8a of the intermediate blade portion 6 and the concave portion 8b provided on the mating surface 14 of the shank 2 make a pair. Two pairs of fitting members are provided on the mating surfaces, but by providing a plurality of pairs in this way, it is possible to prevent the intermediate blade portion from being displaced in the circumferential direction by the action of cutting resistance during machining.

These convex portions and concave portions may be provided in reverse. Further, in FIG. 3 of the present embodiment, the recesses and the projections are cylindrical in shape, and two each are provided. However, the shape of the fitting member and the number of the fitting members are not limited as long as the fitting is possible. For example, a prism, a cone, a pyramid, or a combination thereof may be used.

A third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view of the mating surface of the intermediate blade portion. In the form of replacing the recesses 8a and 8b in the second embodiment with the recesses 8c,
A plurality of recesses 8c are arranged on the mating surfaces 12, 14 around the rotation axis of the tool. At this time, the array is given a certain angular pitch. By doing so, the angles of the peripheral blades between the intermediate blade portions and between the intermediate blade portion and the tip blade portion can be changed. Thus, by providing the outer peripheral blades with an angle or adjusting the angle, the self-excited vibration generated during the rotary cutting of the tool can be suppressed, and a stable machining state can be obtained. That is, by providing more concave portions than the convex portions, it is possible to increase the choices of combinations when fitting the concave portions and the convex portions. Thereby, the angle of the blade part between the units of each blade part can be variously fixed. Therefore, the rotary cutting tool of the present embodiment does not need to use a plurality of types of tools, and the angle can be adjusted freely with a single tool.

A fourth embodiment of the present invention will be described with reference to FIG. The mandrel 17 is tapered so that it gradually becomes thinner toward the end on the attachment side of the leading edge portion 3. Furthermore, the through hole 20 provided in the first intermediate blade portion 15 and the through hole 21 provided in the second intermediate blade portion 16 are tapered. Like the mandrel 17, the taper shape is narrowed toward the end on the attachment side of the leading edge portion 3, and the through holes 20 and 21 are provided so as to be concentric with the rotating shaft like the mandrel 17. Since the through holes 20 and 21 and the mandrel 17 are in contact with each other in a tapered shape, even if a large cutting resistance is applied, the intermediate cutting portion is not easily displaced in the circumferential direction due to the contact resistance. Also, the through hole 2
Since 0, 21 and the mandrel 17 are in contact with each other, the center axis of the mandrel 17 and the center axis of the central blade portion coincide with each other, and it becomes possible to suppress the deflection of the outer peripheral blade of the rotary tool.

Next, the material of the tool will be described with reference to FIG. In the embodiment of the present invention, the tool material can be changed for each blade portion. For example, the cutting edge has a low cutting speed and is easy to break. For example, high-speed steel called high-speed steel can be cited as a material having high toughness. In addition, the first and second intermediate blade portions 25 and 26 that increase the cutting speed may be made of a material excellent in wear, for example, a cemented carbide.

In the Christmas cutter, the tool diameter varies depending on the position of the shaft due to the characteristics of the shape. Therefore, when the tool is rotated at a certain number of revolutions, the cutting speed increases at a portion where the diameter is large, and the cutting speed decreases at a portion where the diameter is small. Therefore, since multiple cutting conditions exist with a single tool, it is difficult to process the entire groove under appropriate conditions with a conventional tool, but the processing conditions can be adjusted by using tools with different materials for each blade. This embodiment that is possible is effective.

Next, an example of the shape of the tool will be described with reference to FIG. In the embodiment of the present invention, the cutting edge shape can be changed for each blade portion. As a result, the following effects can be obtained as an example. For example, the shape of the second intermediate blade portion 36 on the shank 2 side where the amount to be scraped is large and the cutting resistance is applied can be a nick cutting blade, and the resistance can be suppressed. Although illustration is omitted, when the cutting resistance is locally increased, the rake face of the tip edge part, the first intermediate blade part, and the second intermediate blade part is set so that the rake angle of the blade part is increased. By attaching a blade with each or any angle changed, cutting can be improved and cutting resistance can be suppressed. Furthermore, the number of blades of the tip blade portion, the first intermediate blade portion, and the second intermediate blade portion can be partially changed.

The embodiment of the present invention has been illustrated above. However, the present invention is not limited to these descriptions.

As long as the features of the present invention are provided, those skilled in the art appropriately modified the design of the above-described embodiments are also included in the scope of the present invention.

For example, although there are two intermediate blade portions, the first intermediate blade portion 5 and the second intermediate blade portion 6, this is only an example, and the number of intermediate blade portions can be changed as appropriate.

Moreover, each element with which each embodiment mentioned above is combined can be combined as much as possible, and what combined these is also included in the scope of the present invention as long as the characteristics of the present invention are included.

1 blade part, 2 shank, 3 tip blade part, 4a tip blade part side connection part, 4b mandrel side connection part, 7 mandrel, 8 peripheral part, 8a, b, c concave part, 9a, b convex part, 13 core, 10, 11,
20,21 Through hole

Claims (11)

As the cutting edge diameter of the outer periphery of the blade portion goes toward the tip in the longitudinal direction of the rotation axis of the tool, it gradually decreases while increasing or decreasing,
A mandrel that supports the cut and serves as a rotating shaft;
A tool support member that supports the mandrel at the end opposite to the tip side of the blade,
The blade part is composed of a plurality of blade unit units including a tip part unit. The said blade part is divided | segmented by the surface which cross | intersects the rotating shaft of the said rotary cutting tool.
The described rotary cutting tool. 2. The rotary cutting tool according to claim 1, wherein a surface intersecting with a rotation axis of the rotary cutting tool is perpendicular to a longitudinal direction of the rotation axis of the rotary cutting tool. The rotary cutting tool according to claim 1, wherein the tip unit and the tip of the mandrel of the blade unit have a connecting part that can be connected to each other. The rotary cutting tool according to claim 1, further comprising a fitting member having a concavo-convex shape on a surface between the blade unit units or between the blade unit and the tool support member. 6. The rotary cutting tool according to claim 5, wherein the fitting member has more concave portions than convex portions. The rotary cutting tool according to claim 1, wherein an outer diameter of the mandrel is constant. The blade unit other than the tip unit in the blade unit has a through hole, the through hole has a constant diameter, and has a gap when fitted to the mandrel. The described rotary cutting tool. The rotary cutting tool according to claim 1, wherein the outer diameter of the mandrel is a tapered shape that gradually decreases toward the tip of the tool. Of the blade unit, blade units other than the tip unit have a through hole, and the through hole has a tapered shape, and when fitted with the mandrel, the tapered surfaces come into contact with each other. The rotary cutting tool according to claim 9. 10. The blade unit according to claim 9, wherein a part of the blade unit is a nick cutting blade, or a part of the blade unit is a cutting blade having a different number of blades from other blade units. The described rotary cutting tool.

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