Patent Description:
The present invention relates to a cutting tool.

As a cutting tool used for cutting processing of a work material, such as metal, a cutting tool disclosed in Patent Document <NUM> is known.

In Patent Document <NUM>, a cutting tool including a head (main body <NUM>) and a holder <NUM>, which is connected to the back side of the main body <NUM>, is disclosed. In the front portion of the main body <NUM>, a seat portion <NUM> (insert mounting seat) for a cutting insert is provided. The main body <NUM> is also provided with a male shaft <NUM> which extends backward from the rear end portion of the main body <NUM>. When the main body <NUM> is connected to the holder <NUM>, this male shaft <NUM> is inserted into a seat <NUM> inside the holder <NUM>, whereby the position of the main body <NUM>, with respect to the holder <NUM>, is fixed. Patent Document <NUM> relates to a cutting tool according to the preamble of claim <NUM>.

In the configuration of Patent Document <NUM>, the mounting orientation of the cutting insert, installed in the insert mounting seat when the head is installed in the holder, is fixed. Therefore, when a helical flute is processed around a round bar, for example, by using the cutting tool of Patent Document <NUM>, only one type of helical flute can be processed, and a helical flute having a different lead (length that is advanced by one rotation) cannot be processed. In other words, each time when a helical flute having a different lead is processed using the cutting tool of Patent Document <NUM>, a different tool is needed, which may increase the component storage cost.

With the foregoing in view, it is an object of the present invention to provide a cutting tool that can process helical flutes having different leads by using one tool, so as to reduce the component storage cost.

A cutting tool according to an aspect of the present invention is a cutting tool extending along a center axis and including on a front end side a cutting insert to cut a work material, the cutting tool including: a head portion which includes an insert mounting seat, on which the cutting insert is installed, on a front end side; a holder which is installed on a rear end side of the head portion and holds the head portion; and a fixing member which fixes a position of the head portion with respect to the holder when the head portion is mounted on the holder. The head portion is configured to be mountable on the holder, with an angle thereof changing around the center axis.

According to the above aspect, the cutting tool may be fixed to the holder using the fixing member, with the angle of the head portion changing around the center axis, so as to maintain this state. Thereby the radial rake angle of the cutting insert disposed in the head portion can be changed. This makes it possible to process the helical flutes at different radial rake angles using one type of cutting insert. As a result, different helical flutes can be processed using one tool, and the component storage cost can be reduced.

In the above aspect, the head portion may include an engaging portion, constituted of a concave portion and/or a convex portion, on a connecting surface of the head portion that is connected to the holder, and the holder may include an engaged portion, constituted of a convex portion and/or a concave portion engaging with the engaging portion, on a surface of the holder that is connected to the head portion.

In the above aspect, the concave portion may be provided in plurality and formed on a peripheral area of the connecting surface in a circumferential direction.

In the above aspect, the concave portion may be formed at symmetric positions across the center axis.

In the above aspect, at least one of the head portion and the holder may have a scale, and a rotation angle of the head portion may be adjustable by setting with the scale.

In the above aspect, a ring portion is further included, and on one end face of the ring portion, a first engaging portion, which engages with the engaging portion of the head portion, is disposed, and on the other end face of the ring portion, a second engaging portion, which engages with the engaging portion of the holder, is disposed, the head portion is configured to be engageable with the ring portion, with an angle thereof changing around the center axis, the holder is configured to be engageable with a ring portion, with an angle thereof changing around the center axis, and the unit of change of the engaging angle of the head portion with respect to the ring portion is different from the unit of change of the engaging angle of the holder with respect to the ring portion.

In the above aspect, the engaging portion of the holder may be constituted of at least one convex portion, the second engaging portion of the ring portion may be constituted of a plurality of grooves with which the convex portion of the engaging portion of the holder engages, the first engaging portion of the ring portion may be constituted of at least one convex portion, and the engaging portion of the head portion may be constituted of a plurality of grooves with which the convex portion of the first engaging portion of the ring portion engages.

At least one of the head portion and the ring portion may have a scale corresponding to the unit of change of the engaging angle of the head portion with respect to the ring portion, at least one of the ring portion and the holder may have a scale corresponding to the unit of change of the engaging angle of the holder with respect to the ring portion, and a rotation angle of the head portion may be adjustable by setting with the scale.

According to the present invention, a cutting tool, which can process helical flutes having different leads using one tool, so as to reduce the component storage cost, can be provided.

Embodiments of the present invention will be described with reference to the accompanying drawings. In some cases, the dimensions, shapes, angles, and the like of the drawings may be different from the actual dimensions, shapes, angles, and the like. Therefore, the technical scope of the present invention is not limited to the dimensions, shapes, angles, and the like of each component indicated in the drawings.

A configuration of a cutting tool <NUM> according to Embodiment <NUM> will be described with reference to <FIG>. This cutting tool <NUM> is a turning tool that rotates a work material to process it without rotating the tool. <FIG> are diagrams illustrating the configuration of the cutting tool <NUM>. <FIG> are diagrams illustrating a configuration of a head portion <NUM>. <FIG> are diagrams illustrating a configuration of a shank (holder) <NUM>.

The cutting tool <NUM> includes the shank <NUM>, which extends along the center axis O, and a head portion <NUM>. The head portion <NUM> is connected to the shank <NUM> on the front end side (left side in <FIG>).

The head portion <NUM> has an insert mounting seat <NUM> on the front end side thereof, and a cutting insert <NUM> is mounted on the insert mounting seat <NUM>. The cutting insert <NUM> is removably installed on the insert mounting seat <NUM>. In Embodiment <NUM>, the cutting insert <NUM> is installed in the insert mounting seat <NUM>, so that a cutting edge 101a of the cutting insert <NUM> protrudes (left side in <FIG>) from the front end of the head portion <NUM>. The portion of the cutting edge 101a protruding from the head portion <NUM> is used for cutting processing. The shank <NUM> and the head portion <NUM> may be connected such that the tip of the cutting edge 101a of the cutting insert <NUM> is positioned on the axial line of the center axis O (that is, the center axis of the shank <NUM> and the center axis of the head portion <NUM> are on the same axis) in the top view (<FIG>). The cutting insert <NUM> of Embodiment <NUM> is an approximately square-shaped insert in the top view (<FIG>), but the present invention is not limited to the above mode, and the shape of the cutting insert <NUM> may be selected appropriately, so as to match with the shape of the helical flutes (e.g., screw shape, groove shape) to be processed.

A male shaft <NUM> is disposed on the rear end side of the head portion <NUM> at the center area thereof, as illustrated in <FIG>. The male shaft <NUM> is disposed so as to protrude backward (right direction in <FIG> or <FIG>) from the center area of the rear end face <NUM> (connecting surface <NUM> of the head portion <NUM> to be connected to the shank <NUM>) of the head portion <NUM> in the extending direction of the center axis O (hereafter "axial direction"). The male shaft <NUM> has an approximately cylindrical shape with the center axis O as the center. The male shaft <NUM> is disposed so that the male shaft <NUM> is inserted into a shaft hole 205a of a female shaft <NUM> disposed on the shank <NUM> when the head portion <NUM> is installed in the shank <NUM>. Through holes <NUM>, to which bolts <NUM> are inserted, are formed in the head portion <NUM> in the axial direction. When the head portion <NUM> is installed in the shank <NUM>, the bolts <NUM> are inserted into the through holes <NUM> formed in the head portion <NUM>, and tightened to the bolt fastening holes <NUM> of the shank <NUM>, whereby the position of the head portion <NUM> with respect to the shank <NUM> is fixed. In Embodiment <NUM>, a shape of each through hole <NUM>, to which each bolt <NUM> is inserted, is a long hole of which major axis is bent in a circular-arc shape when the head portion <NUM> is viewed from the rear side, and is formed on the peripheral area of the connecting surface <NUM> in the circumferential direction. By forming each through hole <NUM> in this way, when the angle of the head portion <NUM> is changed around the center axis O, the bolt <NUM> can be inserted into the through hole <NUM> in the state after the angle is changed. Thereby the head portion <NUM> and the shank <NUM> can be fixed in the state after the rotation angle of the head portion <NUM> is adjusted. In Embodiment <NUM>, the modes of each bolt <NUM> and each bolt fastening hole <NUM> are not especially limited, and, for example, the bolt <NUM> may have a shaft portion in which a male screw is formed, and be screwed into the bolt fastening hole <NUM> in which a female screw is formed.

The shank <NUM> is a member to hold the head portion <NUM>, and is connected on the rear end side of the head portion <NUM>. The shank <NUM> is extended such that the longitudinal direction thereof is along the center axis O, and has an approximately rectangular parallelepiped shape. As illustrated in <FIG>, the shank <NUM> has a female shaft <NUM> on the front end side thereof, so as to install the head portion <NUM>. The female shaft <NUM> has an approximately cylindrical shape, and the shaft hole 205a, to insert the male shaft <NUM> of the head portion <NUM>, is formed at the center area thereof. The bolt fastening hole <NUM>, to fasten and fix the bolt <NUM>, is formed at each position in the female shaft <NUM> corresponding to each through hole <NUM> of the head portion <NUM>. The bolt fastening hole <NUM> is formed at a plurality of positions on the front end face <NUM> of the shank <NUM> in the circumferential direction at equal intervals.

In the illustrated example, the shank <NUM> has an approximately rectangular parallelepiped shape, but the present invention is not limited to this example, and may have an approximately cylindrical shape or any other shape, for example, as long as the shank <NUM> is a member that is connected to the head portion <NUM> and has a function to hold the head portion <NUM>. The male shaft <NUM> and the female shaft <NUM> are also not limited to the modes in the illustrations, and the shape, size, or the like thereof may be changed, as long as the head portion <NUM> and the shank <NUM> can be connected in the state after the rotation angle of the head portion <NUM> is adjusted.

In Embodiment <NUM>, a number of bolts <NUM> (fixing members) and a number of bolt fastening holes <NUM>, to which the bolts <NUM> are inserted, are <NUM> respectively, but the present invention is not limited to this example, and may be a number of bolts <NUM> or bolt fastening holes <NUM> to fix the head portion <NUM> and the shank <NUM> may be <NUM>, <NUM> or <NUM> or more. Further, in Embodiment <NUM>, the bolt <NUM> is used as an example of the fixing member, but a different member may be used as the fixing member, as long as the member can fix the position of the head portion <NUM> with respect to the shank <NUM>.

According to Embodiment <NUM>, the head portion <NUM> is configured to be mountable on the shank <NUM> with changing the angle around the center axis O. In other words, the head portion <NUM> can be fixed to the shank <NUM> in the state after the relative angle (rotational angle around the center axis O) of the head portion <NUM> with respect to the shank <NUM> is adjusted. The angle adjustment mechanism of the head portion <NUM> with respect to the shank <NUM> will now be described.

As illustrated in <FIG> and <FIG>, a plurality of concave portions <NUM> are formed on the connecting surface <NUM>, which is connected to the shank <NUM>, of the head portion <NUM>, and the concave portions <NUM> are engaged with the convex portions <NUM> of the shank <NUM> when the head portion <NUM> is installed in the shank <NUM>. By this engagement of the concave portions <NUM> formed on the rear end face <NUM> of the head portion <NUM> and the convex portions <NUM> formed on the front end face <NUM> of the shank <NUM>, the position of the head portion <NUM> with respect to the shank <NUM> is adjusted, and the orientation thereof (mounting orientation of the cutting insert <NUM> installed on the front end of the head portion <NUM>) can be held. As described above, the position of the head portion <NUM> with respect to the shank <NUM> is fixed by fastening the bolts <NUM>.

The connecting surface <NUM> has an approximately circular shape in the side view (when the head portion <NUM> is viewed from the rear end side, as illustrated in <FIG>), and a plurality of concave portions <NUM> are formed on the peripheral area of the connecting surface <NUM> in the circumferential direction at equal intervals. Since a plurality of concave portions <NUM> are formed, the rotation angle of the head portion <NUM> with respect to the shank <NUM> can be adjusted in multiple steps. In Embodiment <NUM>, the concave portions <NUM> are formed in the peripheral area of the connecting surface <NUM> in the circumferential direction at <NUM>° intervals, and the concave portions <NUM> as a whole can adjust the rotation angle of the head portion <NUM> in a -<NUM>° ≤ α ≤ <NUM>° range, that is, in a ±<NUM>° range around the center axis O.

In this way, the radial rake angle of the cutting insert <NUM> disposed in the head portion <NUM> can be changed by changing the angle of the head portion <NUM> around the center axis O, and fixing the shank <NUM> and the head portion <NUM> by fastening the bolts <NUM> such that this changed state can be maintained. Thereby, processing at different radial rake angles can be implemented using one type of cutting insert <NUM>. In concrete terms, as illustrated in <FIG> and <FIG>, for example, in a case where a reference position (radial rake angle of the cutting insert <NUM> is <NUM>°) is a position where the head portion <NUM> is installed in the shank <NUM> (the concave portions <NUM> are engaged with the convex portions <NUM>), such that an indication groove S1 of the head portion <NUM> is set to the position indicting <NUM>° of the scale S2 of the shank <NUM>, the head portion <NUM> can be installed in the shank <NUM> to perform cutting processing in a state after the radial rake angle of the cutting insert <NUM> is adjusted in a positive direction or a negative direction (-<NUM>° ≤ α ≤ <NUM>°) from the reference position. Since processing at a different radial rake angle is possible, different helical flutes having different leads can be processed using one tool, whereby the component storage cost can be reduced.

In the illustration examples, the concave portions <NUM> formed on the connecting surface <NUM> of the head portion <NUM> are formed at symmetric positions with respect to the center axis O in the -<NUM>° ≤ α ≤ <NUM>° range (<FIG>) at <NUM>° intervals. The convex portions <NUM> that engages with the concave portions <NUM> are formed at symmetric positions with respect to the center axis O. However, the present invention is not limited to this example, where the concave portions <NUM> and the convex portions <NUM> are at symmetric positions with respect to the center axis O. For example, a plurality of concave portions <NUM> may be disposed at one location on the peripheral area of the connecting surface <NUM>, and one convex portion <NUM> that engages with the concave portions <NUM> may be disposed, whereby the angle of the head portion <NUM> can be adjusted around the center axis O. Further, the concave portions <NUM> may be disposed at <NUM> or more locations on the peripheral area of the connecting surface <NUM>, and <NUM> or more convex portions <NUM> may be disposed so as to correspond to the concave portions <NUM>. In other words, the positions and numbers of the concave portions <NUM> and the convex portions <NUM> may be changed, as long as the head portion <NUM> can be installed in the shank <NUM> with changing the angle around the center axis O.

According to Embodiment <NUM>, the scale S (indication groove S1 of the head portion <NUM> and scale S2 of the shank <NUM>) that allow to visually recognize the adjusted angle of the head portion <NUM> are formed on the outer peripheral surface of the female shaft <NUM> disposed on the front end side of the shank <NUM>. By setting the indication groove S1 to the scale S2 of the shank <NUM>, the head portion <NUM> can be accurately set to an arbitrary angle compared with the configuration without the scale, and the angle can be easily adjusted. In Embodiment <NUM>, the notches of the scale S2 are formed at <NUM>° intervals, but the notches of the scale (interval of the notches) may be arbitrarily set in accordance with the adjustment angle of the head portion <NUM>.

<FIG> is an enlarged view depicting a region including the concave portions <NUM> and the convex portion <NUM> when the head portion <NUM> and the shank <NUM> are connected. As illustrated in <FIG>, the convex portion <NUM> formed in the shank <NUM> has a cone-shaped cross-section, protruding from the front end face <NUM> of the shank <NUM> toward the front side in the axial direction (left side in <FIG> and <FIG>). An angle θg formed by the extended lines (broken lines in <FIG>) of the sides of the convex portion <NUM> is set to <NUM>°, for example. Each concave portion <NUM> formed on the rear end face <NUM> of the head portion <NUM> has a concave shape along the outer edge of the convex portion <NUM>, and is preferably concave from the rear end face <NUM> of the head portion <NUM>, so as to position along the outer edge of the convex portion <NUM> with a gap G. In other words, there is a gap G, as illustrated in <FIG>, between the ridge of the convex portion <NUM> and the groove of the concave portion <NUM>. When the head portion <NUM> and the shank <NUM> are installed, the position of the head portion <NUM> is fixed by fastening the bolt <NUM> in the state of maintaining the gap G in this way. By this configuration, the convex portion <NUM> and the concave portion <NUM> can be prevented from contacting with each other each time the head portion <NUM> is installed in the shank <NUM> with changing the angle around the center axis O, and, as a result, abrasion between the concave portion <NUM> and the convex portion <NUM> can be suppressed.

In Embodiment <NUM> described above, the concave portion <NUM> (engaging portion) is disposed in the head portion <NUM>, and the convex portion <NUM> (engaged portion) is disposed in the shank <NUM>, in order to adjust the angle of the head portion <NUM> around the center axis O, but a reverse configuration (in other words, the convex portion (engaging portion) is disposed in the head portion <NUM>, and the concave portion <NUM> (engaged portion) is disposed in the shank <NUM>) may be used.

Further, in Embodiment <NUM> described above, the concave portions <NUM> are disposed in the head portion <NUM>, and the convex portions <NUM> are disposed in the shank <NUM>, and at the same time, the scale S (indication groove S1 of the head portion <NUM> and scale S2 of the shank <NUM>) are disposed to visually recognize the adjusted angle of the head portion <NUM>, but only the concave portions <NUM> and the convex portions <NUM> may be disposed without disposing the scale S. Thereby the angle of the head portion <NUM> can easily be adjusted in accordance with the shapes of the concave portions <NUM> and the convex portions <NUM>, which are formed at a predetermined interval in advance. By disposing the concave portions <NUM> and the convex portions <NUM> (that is, a configuration with serration operability to adjust the angle improves, and operation time can be decreased.

<FIG> and <FIG> are perspective views depicting a head portion 10B and a shank 20B of the cutting tool of Embodiment <NUM> respectively. <FIG> is a perspective view when the head portion 10B is viewed from the rear side, and <FIG> is a perspective view when the shank 20B is viewed from the front side (front end side). In the head portion 10B and the shank 20B illustrated in <FIG> and <FIG>, configuration of the head portion <NUM> and the shank <NUM> described in Embodiment <NUM> are modified, and the other configurations and functions are the same as Embodiment <NUM>. Therefore, a composing element the same as the head portion <NUM> or the shank <NUM> described in Embodiment <NUM> is denoted with the same reference sign as Embodiment <NUM>, and description thereof is omitted.

As illustrated in <FIG> and <FIG>, the concave portions <NUM> and the convex portions <NUM> described in Embodiment <NUM> are not disposed in the connecting portion (connecting surface 11b illustrated in <FIG>, and front end face 21b illustrated in <FIG>) between the head portion 10B and the shank 20B in Embodiment <NUM>. Thereby the angle of the head portion 10B can be adjusted freely within a movable range of the radial rake angle. Compared with the configuration including the concave portions <NUM> and the convex portions <NUM> described in Embodiment <NUM>, a finer angle adjustment can be performed. In Embodiment <NUM>, the scale (scales S1 and S2) are formed in the head portion 10B and the shank 20B, just like Embodiment <NUM>, hence the adjusted angle can be confirmed.

<FIG> are diagrams depicting a configuration of a cutting tool 1C of Embodiment <NUM>. <FIG> is a front view when the cutting tool 1C of Embodiment <NUM> is viewed in the same direction as <FIG>. <FIG> is a right side view when a head portion 10C is viewed in the same direction as <FIG>. <FIG> is a left side view when a shank 20C is viewed in the same direction as <FIG>. In the cutting tool 1C (head portion 10C and shank 20C) illustrated in <FIG>, the shape of the connecting portion between the head portion <NUM> and the shank <NUM> described in Embodiment <NUM> is modified, and the other configurations and functions are the same as Embodiment <NUM>. Therefore, a composing element the same as Embodiment <NUM> is denoted with a same reference sign as Embodiment <NUM>, and description thereof is omitted.

As illustrated in <FIG>, in Embodiment <NUM>, a diameter of the connecting portion between the head portion 10C and the shank 20C is enlarged. Specifically, an outer diameter D1 of the connecting surface 11c and the front end face 21c, where the head portion 10C and the shank 20C are connected, is larger than the outer diameter D2 (<FIG>) of the shank 20C. Thereby the pitch of the concave portions 107c formed on the peripheral area of the connecting surface 11c of the head portion 10C can be finer than the configuration of Embodiment <NUM>. In other words, the concave portions <NUM> in Embodiment <NUM> are formed in the peripheral area of the connecting surface <NUM> in the circumferential direction at θ = <NUM>° intervals (<FIG>), while the concave portions 107c in Embodiment <NUM> can be formed at the smaller angle θc (<FIG>) than θ (<FIG>) in Embodiment <NUM>. By engaging the concave portions 107c formed like this and the convex portions 207c on the front end face 21c of the shank 20c to adjust the angle of the head portion 10C, the angle can be more finely adjusted.

<FIG> are diagrams depicting a configuration of a cutting tool 1D of Embodiment <NUM> respectively. <FIG> is a perspective view of the cutting tool 1D viewed from the front side. <FIG> is an exploded perspective view depicting the exploded state of the configuration of the cutting tool 1D. <FIG> is a diagram depicting a ring portion <NUM> in <FIG> and <FIG>. In the cutting tool 1D illustrated in <FIG>, the configuration of the ring portion <NUM> is added to the head portion <NUM> and the shank <NUM> described in Embodiment <NUM>, and the other configurations and functions are the same as Embodiment <NUM>. Therefore, a composing element the same as the head portion <NUM> or the shank <NUM> described in Embodiment <NUM> is denoted with the same reference sign as Embodiment <NUM>, and description thereof is omitted.

As illustrated in <FIG> and <FIG>, in Embodiment <NUM>, the ring portion <NUM> is disposed between the head portion <NUM> and the shank <NUM> described in Embodiment <NUM>. <FIG> is a left side view of the ring portion <NUM> viewed from the front side, <FIG> is a front view of the ring portion <NUM> viewed from the same direction as <FIG>, and <FIG> is a right side view of the ring portion <NUM> viewed from the rear side.

The ring portion <NUM> is formed approximately in a circular shape in the view in the center axis O direction. At the center of the ring portion <NUM>, a through hole <NUM>, to insert the male shaft <NUM> of the head portion <NUM>, is formed. The male shaft <NUM> of the head portion <NUM> is inserted through this through hole <NUM> into the shaft hole 205a of the female shaft <NUM> of the shank <NUM>, so as to connect the head portion <NUM> and the shank <NUM>. Through holes <NUM> to insert the bolts <NUM> are formed on the peripheral area of the ring portion <NUM> at positions corresponding to the through holes <NUM> of the head portion <NUM>. By fastening the bolts <NUM>, inserted into the through holes <NUM> of the head portion <NUM>, in the bolt fastening hole <NUM> of the shank <NUM> via the through hole <NUM> of the ring portion <NUM> (see <FIG> and the like), the head portion <NUM> and the shank <NUM> can be fixed via the ring portion <NUM>.

As illustrated in <FIG>, convex portions 307a (first engaging portions) are formed on a front end face 31a of the ring portion <NUM>, and concave portions 307b (second engaging portions) are formed on a rear end face 31b of the ring portion <NUM>. A plurality of concave portions 307b are formed on the peripheral area of the rear end face 31b along the circumferential direction at equal intervals. The convex portions 307a formed on the front end face 31a of the ring portion <NUM> are configured to be engageable with the plurality of concave portions <NUM> (engaging portions) formed on the connecting surface <NUM> of the head portion <NUM>, and the plurality of concave portions 307b formed on the rear end face 31b of the ring portion <NUM> are configured to be engageable with the convex portions <NUM> (engaging portions) formed on the shank <NUM>. Because of this configuration, the engagement between the plurality of concave portions <NUM> formed on the head portion <NUM> and the convex portions 307a of the ring portion <NUM> can be adjusted, so as to adjust the angle (engaging angle) of the head portion <NUM> with respect to the ring portion <NUM>, and the engagement between the plurality of concave portions 307b formed on the ring portion <NUM> and the convex portions <NUM> of the shank <NUM> can be adjusted, so as to adjust the angle (engaging angle) of the shank <NUM> with respect to the ring portion <NUM>, and as a result, the angle of the head portion <NUM> with respect to the shank <NUM> can be adjusted via the ring portion <NUM>. The unit of the change of the engaging angle of the head portion <NUM> with respect to the ring portion <NUM> is different from the unit of the change of the engaging angle of the shank <NUM> with respect to the ring portion <NUM>. For example, the concave portions <NUM> of the head portion <NUM> are formed on the peripheral area of the connecting surface <NUM> in the circumferential direction at θ = <NUM>° intervals (<FIG>), and the concave portion 307b of the ring portion <NUM> are formed on the peripheral area of the rear end face 31b in the circumferential direction at θd = <NUM>° intervals (<FIG>). By adjusting the respective angles via the ring portion <NUM>, the radial rake adjusting angle of the head portion <NUM> can be adjusted at <NUM>° intervals.

<FIG> is a cross-sectional view depicting the configuration of the vicinity of a bolt of the cutting tool 1E of Embodiment <NUM>. In the cutting tool 1E of Embodiment <NUM>, the configuration of the bolt 103e and the vicinity thereof is modified, and the other configurations and functions are the same as Embodiment <NUM>. Therefore, a composing element the same as the head portion <NUM> or the shank <NUM> described in Embodiment <NUM> is denoted with the same reference sign as Embodiment <NUM>, and description thereof is omitted.

<FIG> indicates a state where a concave portion <NUM> of the head portion <NUM> and the convex portion <NUM> of the shank <NUM> are engaged, and <FIG> indicates a state where the engagement of the concave portion <NUM> of the head portion <NUM> and the convex portion <NUM> of the shank <NUM> is released. In Embodiment <NUM>, the length of the thread engagement L3 of the bolt 103e is larger than the height L1 of the convex portion <NUM>. Thereby even in the state where the engagement of the concave portion <NUM> and the convex portion <NUM> is released (<FIG>), the bolt 103e can maintain the fastened state with the bolt fastening hole <NUM>. As a result, the radial rake adjustment of the head portion <NUM> can be performed merely by loosening the bolt 103e without completely removing the bolt 103e.

<FIG> are diagrams depicting the configuration of a cutting tool 1F of Embodiment <NUM>. <FIG> is a front view when the cutting tool 1F of Embodiment <NUM> is viewed in the same direction as <FIG>. <FIG> is an enlarged view of a portion indicated by the broken line frame a in <FIG>. <FIG> is an exploded perspective view depicting the exploded state of the configuration of the cutting tool 1F in <FIG> diagonally viewed from the rear side. <FIG> is an exploded perspective view depicting the exploded state of the configuration of the cutting tool 1F in <FIG> diagonally viewed from the front side. In the cutting tool 1F of Embodiment <NUM>, the configuration of the scale of the cutting tool 1D of Embodiment <NUM> (<FIG> and <FIG>) is modified, and the other configurations and functions are the same as Embodiment <NUM>. Therefore, a composing element the same as Embodiment <NUM> is denoted with the same reference sign as Embodiment <NUM>, and description thereof is omitted. The interval θ of the notches of the scale S2 of the head portion 10F (<FIG>) matches with the serration interval θ of the concave portions <NUM> of the head portion 10F (<FIG>), and the interval θ of the notches of the scale S2 is <NUM>°, for example. The interval θd of the notches of the scale S3 of the ring portion 30F (<FIG>) matches with the serration intervals θd of the concave portions 307b of the ring portion 30F (<FIG>), and the interval θd of the notches of the scale S3 is <NUM>°, for example.

In the cutting tool 1F of Embodiment <NUM>, as illustrated in <FIG>, the scale is not formed on the shank 20F, but is formed on the head portion 10F and the ring portion 30F respectively. Specifically, the scale S2 is formed in the head portion 10F at θ = <NUM>° intervals, and the indication groove S1, to set the scale S2, is formed on the ring portion 30F (the head portion 10F side of the ring portion 30F). The scale S3 is formed on the shank 20F side of the ring portion 30F at θd = <NUM>° intervals, and an indication groove S1, to set the scale S3, is formed in the shank 20F. By forming the scale S2 in the head portion 10F at θ = <NUM>° intervals, and forming the indication groove S1, to set the scale S2, on the ring portion 30F, the head portion 10F can be easily adjusted with respect to the ring portion 30F at <NUM>° intervals. Further, by forming the scale S3 in the ring portion 30F at θd = <NUM>° intervals, and forming the indication groove S1 on the shank 20F, the shank 20F can be easily adjusted with respect to the ring portion 30F at <NUM>° intervals. By combining the angle adjustment of the ring portion 30F and the angle adjustment of the head portion <NUM> configured in this way, the radial rake adjusting angle of the head portion <NUM> can be adjusted at <NUM>° intervals, and finer angle adjustment can be performed.

Claim 1:
A cutting tool (<NUM>) extending along a center axis (O), and including on a front end side a cutting insert (<NUM>) to cut a work material, the cutting tool comprising:
a head portion (<NUM>) which includes an insert mounting seat (<NUM>), on which the cutting insert is installed, on a front end side;
a holder (<NUM>) which is installed on a rear end side of the head portion and holds the head portion; and
a fixing member (<NUM>) which fixes a position of the head portion with respect to the holder when the head portion is mounted on the holder, wherein
the head portion is configured to be mountable on the holder, with an angle thereof changing around the center axis,
and the cutting tool (<NUM>) is characterized in that it further comprises a ring portion (<NUM>), wherein
on one end face of the ring portion, a first engaging portion (307a), which engages with an engaging portion (<NUM>) of the head portion, is disposed, and on the other end face of the ring portion, a second engaging portion (307b), which engages with an engaging portion (<NUM>) of the holder, is disposed,
the head portion is configured to be engageable with the ring portion, with an angle thereof changing around the center axis,
the holder is configured to be engageable with the ring portion, with an angle thereof changing around the center axis, and
the unit of change of the engaging angle of the head portion with respect to the ring portion is different from the unit of change of the engaging angle of the holder with respect to the ring portion.