JP6358306B2 - Replaceable cutting head - Google Patents

Description

  The present invention relates to an exchangeable cutting head that is detachably attached to the tip of a tool body and used for cutting.

2. Description of the Related Art Conventionally, there is known an exchangeable cutting head having a head body that is detachably attached to a tip end of a tool body rotated about an axis by screwing. On the outer periphery of the head body, a plurality of chip discharge grooves that extend along the axial direction and are spaced apart in the circumferential direction along the axis, and a cutting blade that extends along the chip discharge groove, the head The outer periphery of the main body is formed so as to be cut out in a planar shape, and is provided with a pair of hooking surfaces that are arranged backward (placed back to back) across the axis at the base end along the axial direction.
A working tool such as a wrench can be latched (locked) on the pair of retaining surfaces, and by rotating the exchangeable cutting head around the axis with respect to the tool body by this working tool, The exchangeable cutting head is attached and detached.

For example, in Patent Document 1 below, a fastening male screw and a fastening female screw that are provided on one and the other of a machining head (exchangeable cutting head) and a holder (tool body) are screwed together. Thus, there is described a machining head exchangeable rotating tool in which a machining head is detachably attached to the tip of a holder.
In this machining head replaceable rotary tool, the machining head and the holder are provided with contact surfaces that are brought into contact with each other in the fastening state in which the fastening male screw and the fastening female screw are screwed together. In addition, the fastening female screw is integrally rotated through the holder in the direction of rotation of the tool, which is easily tightened by the machining load, thereby performing predetermined machining by the machining head and machining by the contact of the contact surface. It is prevented that the fastening male screw and the fastening female screw are further tightened by the load.
Further, in Patent Document 1, as a tool locking portion (holding portion) for locking a working tool for screwing a fastening male screw and a fastening female screw, a head body of an exchangeable cutting head is provided. In addition, it is described that a pair of two flat chamfered locking surfaces (hanging surfaces) are provided in parallel to each other at symmetrical positions with respect to the axis.

JP 2010-284552 A

However, the conventional exchangeable cutting head has the following problems.
In this type of replaceable cutting head, there are known ones in which a plurality of chip discharge grooves provided on the outer periphery of the head body are arranged at unequal intervals so as to have different widths along the circumferential direction. Thus, there is room for improvement in preventing clogging of chips, particularly in a chip discharge groove having a narrow width among the plurality of chip discharge grooves having unequal intervals (unequally divided).

In addition, the rigidity in the circumferential portion of the head body where the circumferentially wide chip discharging groove is located among the plurality of unequal spaced chip discharging grooves is larger than the rigidity in a portion other than the circumferential portion. It was easy to be low.
Also, the pair of hooking surfaces makes it easy to reduce the rigidity of the head body in a predetermined direction. Specifically, since these latching surfaces are formed so as to cut out the outer periphery of the head body in a flat shape, the rigidity of the circumferential portion of the head body where the latching surface is located was likely to be lowered. .
Under such circumstances, the strength balance of the head body is lost, and chatter vibration is generated during the cutting process, which may affect the machining accuracy.

  In Patent Document 1, the replaceable cutting head is configured with a cutting blade or the like corresponding to the type of the tool, and is configured with a predetermined tool material such as cemented carbide or high-speed tool steel. In addition, it describes that the head main body is coated with a compound film such as TiN, TiCN, TiAlN, or CrN, or a hard film (coating film) such as a DLC film or a diamond film, if necessary. Since the exchangeable cutting head having such a configuration is more complex and more complicated to manufacture than a tool body that can share parts, it is preferable to make the length along the axial direction as small as possible.

  However, when the exchangeable cutting head is simply made small, the base end portion (rounded-up portion) of the chip discharge groove easily interferes with the latching portion. Due to this interference, when both end edges (edges) along the circumferential direction of the latching part are notched by the chip discharge groove, the work of rotating the head body with the work tool is affected.

  The present invention has been made in view of such circumstances, and can suppress chatter vibrations and the like during cutting, and can improve chip discharge performance even in a chip discharge groove having a narrow width. The processing accuracy and processing stability of the head can be sufficiently increased, and the head body can be stably rotated by the working tool when attaching to and detaching from the tool body, while making the head body small to reduce manufacturing costs. It is an object of the present invention to provide a replaceable cutting head capable of satisfying the requirements.

In order to solve such problems and achieve the above object, the present invention proposes the following means.
That is, the present invention is an exchangeable cutting head having a head body that is removably attached by screwing to the tip of a tool body that is rotated about an axis, and the outer periphery of the head body is provided in the axial direction. A plurality of chip discharging grooves extending along the chip discharging edge, a cutting blade extending along the chip discharging groove, and an outer periphery of the head main body formed to be cut out in a planar shape, and the axis line at the base end along the axial direction. A pair of hooking surfaces disposed on the back side of the first chip, and the plurality of chip discharge grooves include a first chip discharge groove and at least a base end portion along the axial direction. A second chip discharge groove having a narrower width along the circumferential direction around the axis than the chip discharge groove, and at least one of the pair of hook surfaces is the second hook surface. and it continues to the proximal end portion of the chip discharge groove, the head The body is formed with a latching portion in which the pair of latching surfaces are formed, the latching portion has the same or a small diameter as the outer diameter of the cutting blade, and the second chip discharge groove is A main groove, and a sub groove adjacent to the front of the main groove in the tool rotation direction and having a width in the circumferential direction narrower than the main groove, and at least of the pair of hooking surfaces. Both end edges of the one latching surface along the circumferential direction extend in a ridge shape on the outer periphery of the head main body without being cut into the main groove .

According to the exchangeable cutting head of the present invention, a pair of hooking surfaces on which a working tool such as a wrench is hooked (locked) are arranged backward (disposed back to back) at the base end of the outer periphery of the head body. Among the plurality of chip discharge grooves, the base end portion (rounded up portion) of the second chip discharge groove that is narrower than the first chip discharge groove, Since at least one latching surface is connected, the following effects are achieved.
In this specification, “the latching surface is continuous with the base end portion of the chip discharge groove” means that the base end portion (round-up portion) of the chip discharge groove is opened adjacent to the surface of the hooking surface. Represents the state.

First, as a first effect, it is easy to ensure the balance of rigidity of the head body evenly in the circumferential direction.
Specifically, among the first and second chip discharge grooves having different circumferential widths, the circumferential portion of the head body in which the first chip discharge groove having a wide circumferential width is formed is , The rigidity is likely to be lower than that of the portion other than the circumferential portion. Further, the circumferential direction portion of the head body where the latching surface formed so as to cut out the outer periphery of the head body in a planar shape is compared with the circumferential direction portion of the head body where the latching surface is not formed, Stiffness tends to be low.
Therefore, in the present invention, it is ensured that a portion in which the rigidity in the circumferential direction is remarkably reduced is generated in the head main body by connecting the latching surface to the base end portion of the second chip discharge groove having a narrow width. I was able to suppress it.

Specifically, at the base end of the head body, the rigidity of the head body is lowered so that the pair of hooking surfaces are oriented backwards, while the head body is positioned on the tip side from the base end of the head body. In the portion to be applied, the rigidity is lowered so as to be along a direction other than the direction in which these hooking surfaces face backward (for example, the direction in which the first chip discharge grooves face backward).
As described above, since the portion of the head main body having low rigidity is distributed in the circumferential direction at each portion in the axial direction, the strength balance of the head main body as a whole can be easily ensured in the circumferential direction. Thereby, it can suppress that chatter vibration etc. arise at the time of cutting.

In addition, as a second effect, it is possible to improve chip discharge performance even in the second chip discharge groove where the width of the base end portion is narrow.
That is, since the hooking surface formed so as to cut out the outer periphery of the head main body is connected to the base end portion (rounded-up portion) of the second chip discharge groove, the hooking surface is exchanged. It is easy to secure a space between the work surface of the work material cut by the type cutting head. That is, it is possible to avoid a situation in which the latching surface acts like a chip pocket and the chips flowing in the second chip discharge groove are clogged by the raised portion of the groove, and the chip discharge performance is improved.

As a third effect, it is possible to stably perform the operation of attaching and detaching the head main body to the tool main body while reducing the manufacturing cost by reducing the length along the axial direction of the head main body.
That is, the hooking surface on which the work tool is hooked is arranged at the base end portion of the outer periphery of the head main body and is connected to the base end portion of the chip discharge groove. Compared to the configuration in which the latching surface and the chip discharge groove are arranged with an interval in the axial direction as in Patent Document 1, it is easy to keep the length of the head body along the axial direction small.

  Specifically, compared to a tool body that is easy to make parts common and easy to manufacture at low cost, the replaceable cutting head is made of an expensive material such as cemented carbide and the cutting blade is coated. The manufacturing process is complicated, and various types of cutting blades are provided according to the type of tool, so that the length along the axial direction of the head body is reduced as in the present invention. By suppressing the manufacturing cost, the manufacturing cost is reduced and the parts management becomes easy.

  Further, the chip discharge groove having the latching surface continuous on the outer periphery of the head main body is the second chip discharge groove whose base end portion is narrow, and therefore the circumferential direction of the latching surface by the second chip discharge groove. It is suppressed that both end edges (edges) are notched. That is, according to the present invention, it is easy to ensure a large contact (contact) length along the circumferential direction between the latching surface and the work tool latched on the latching surface. Therefore, it becomes easy to stably rotate the exchangeable cutting head by the work tool, and the workability of attaching / detaching the exchangeable cutting head to / from the tool body is improved.

  As described above, according to the exchangeable cutting head of the present invention, chatter vibration and the like at the time of cutting can be suppressed, and chip discharge performance can be improved even in a narrow chip discharge groove. Processing stability can be sufficiently increased, and the head body can be stably rotated by a working tool when attaching to and detaching from the tool body while reducing the manufacturing cost by making the head body small. .

Moreover, the exchangeable cutting head of this invention WHEREIN: The said chip discharge groove | channel is good also as an odd number being formed in the outer periphery of the said head main body .

  According to the exchangeable cutting head of the present invention, chatter vibrations and the like during cutting can be suppressed, and chip discharge performance can be improved even in a chip discharge groove with a narrow width. Can be sufficiently increased, and the head body can be stably rotated by the working tool when being attached to and detached from the tool body while making the head body small to reduce the manufacturing cost.

It is a side view which shows the exchangeable cutting head which concerns on one Embodiment of this invention. It is a side view which shows the exchangeable cutting head which concerns on one Embodiment of this invention. It is a front view which shows the exchangeable cutting head which concerns on one Embodiment of this invention. It is a figure which shows the AA cross section of FIG. It is a figure which shows the BB cross section of FIG. It is a figure which shows CC cross section of FIG. It is a figure explaining the exchange type cutting head concerning a reference example from which technical thought differs from the present invention, and corresponds to the AA section of Drawing 1. It is a figure explaining the exchange-type cutting head concerning the reference example from which this invention differs in technical thought, and respond | corresponds to the BB cross section of FIG. It is a figure explaining the exchange-type cutting head concerning the reference example from which this invention differs in technical thought, and respond | corresponds to CC cross section of FIG.

Hereinafter, a replaceable cutting head 10 according to an embodiment of the present invention will be described with reference to the drawings.
The exchangeable cutting head 10 of the present embodiment is detachably attached to the tip of a tool body (not shown) such as a holder (shank) that rotates around an axis O in an axial shape, for example, by screwing. It constitutes a head exchange-type cutting tool (head exchange-type cutting tool), and is used, for example, for end milling, drilling, reaming and the like. As shown in FIGS. 1 to 3, the exchangeable cutting head 10 described in the present embodiment has a radius end mill shape.

The exchangeable cutting head 10 includes a head body 1 integrally formed of a hard material such as cemented carbide, a connecting member 2 integrally formed of a metal material such as a steel material having a hardness lower than that of the head body 1, and It has. The head body 1 is formed with a cutting edge portion 3, a latching portion 4, and a mounting portion 5 in order from the distal end side (left side in FIGS. 1 and 2) to the proximal end side (right side in FIGS. 1 and 2). In addition, the connecting member 2 is provided with a screw portion 2a that protrudes further from the attachment portion 5 toward the proximal end side.
Here, the head main body 1 has a multi-stage columnar shape, and the connecting member 2 has a columnar shape having a smaller diameter than the head main body 1, and these are coaxially arranged with the axis O as a common axis. In the present specification, the head body 1 side along the axis O direction of the replaceable cutting head 10 is referred to as the distal end side, and the connecting member 2 side along the axis O direction is referred to as the proximal end side. A direction orthogonal to the axis O is referred to as a radial direction, and a direction around the axis O is referred to as a circumferential direction. Of the circumferential directions, the direction in which the exchangeable cutting head 10 is rotated with respect to the work material during cutting is referred to as the tool rotation direction T (or the front of the tool rotation direction T). The direction toward the opposite is referred to as the rear of the tool rotation direction T (see FIGS. 3 to 6).
Further, “the outer periphery of the head main body 1” in this specification refers to a portion exposed to the outer periphery of the tool when the head main body 1 is mounted on the tool main body. The outer periphery of the blade part 3 and the latch part 4 is pointed out.

1 and 2, the cutting blade portion 3 of the head body 1 has a substantially cylindrical shape with an axis O as the center, and a plurality of outer peripheral edges of the cutting blade portion 3 extend along the axis O direction. A chip discharge groove 8 and an outer peripheral blade (cut blade) 6 extending along the chip discharge groove 8 are formed. A plurality of outer peripheral blades 6 are formed on the outer periphery of the head main body 1 at unequal intervals in the circumferential direction, and the chip discharge grooves 8 that constitute the rake face of the outer peripheral blade 6 are also uneven in the circumferential direction. A plurality are formed at equal intervals. Here, the phrase “with unequal intervals in the circumferential direction” as used in this specification includes a state in which “there are unequal intervals in the circumferential direction at least at any position along the axis O direction”. The specific arrangement of the outer peripheral blade 6 and the chip discharge groove 8 will be described later.
In the example of the present embodiment, as shown in FIG. 3, the plurality of chip discharge grooves 8 are arranged at equal intervals in the circumferential direction at the tips along the axis O direction, while in FIGS. 1 and 2. As shown, since the leads of a main groove 12 and a sub-groove 13 described later of each chip discharge groove 8 are different from each other, the leads are set at unequal intervals in the circumferential direction from the tip toward the base end along the axis O direction. In addition, the base end portion (rounded-up portion) of the chip discharge groove 8 is also unequally spaced. In other words, the chip discharge grooves 8 are unequal leads, and are unequally spaced in the circumferential direction at least at the base end along the direction of the axis O. Although not particularly illustrated, these chip discharge grooves 8 may be arranged at unequal intervals in the circumferential direction while being equally lead to each other.

  A plurality of chip discharge grooves 8 are provided on the outer periphery of the head body 1, and an even number (four in the illustrated example) of chip discharge grooves 8 is formed in the present embodiment. The replaceable cutting head 10 of the present embodiment is a head replaceable end mill, and these chip discharge grooves 8 gradually move backward in the tool rotation direction T from the distal end of the cutting blade portion 3 toward the proximal end side. And twisted. Further, an outer peripheral edge 6 having a rake face as the wall surface is formed at the outer peripheral side ridge portion of the wall surface facing the tool rotation direction T in the chip discharge groove 8. As it goes from the distal end to the proximal end side, it gradually twists and extends backward in the tool rotation direction T.

  In addition, the plurality of chip discharge grooves 8 are narrower in the circumferential direction than the first chip discharge groove 8A and the first chip discharge groove 8A and at least the base end portion (rounded-up portion) along the axis O direction. And a second chip discharge groove 8B. That is, the groove width of the base end portion in the second chip discharge groove 8B is narrower than the groove width of the base end portion in the first chip discharge groove 8A. In the present embodiment, the second chip discharge The groove width of the groove 8B is the same as the groove width of the first chip discharge groove 8A only at the tip thereof, but is narrower than the groove width of the first chip discharge groove 8A at a portion other than the tip. . As described above, the first chip discharge grooves 8A and the second chip discharge grooves 8B having different circumferential widths are formed on the outer periphery of the cutting blade portion 3 in two rows so as to be alternately arranged in the circumferential direction. As a result, the arrangement pitch between the chip discharge grooves 8 adjacent to each other in the circumferential direction (the arrangement pitch of the outer peripheral blades 6) is such that narrow portions (narrow pitch) and wide portions (wide pitch) appear alternately in the circumferential direction. It has become.

  Specifically, in the cross-sectional view shown in FIGS. 4 and 7, the center that is an obtuse angle among the center angles θ centering on the axis O formed between the peripheral blades 6 adjacent in the circumferential direction. The chip discharge groove 8 corresponding to the angle θA (FIG. 7) is defined as a wide first chip discharge groove 8A, and the chip discharge groove 8 corresponding to the acute central angle θB (FIG. 4) is a narrow second. It is a chip discharge groove 8B.

  Each chip discharge groove 8 is adjacent to the main groove 12 that forms the outer peripheral blade 6 and its rake face and the front of the main groove 12 in the tool rotation direction T, and has a width in the circumferential direction that is greater than that of the main groove 12. A sub-groove 13 that is narrowly formed. In the example of the present embodiment, the first and second chip discharge grooves 8A and 8B have the main grooves 12A and 12B having substantially the same cross-sectional shape (particularly the shape from the rake face to the groove bottom). The sub-grooves 13A and 13B have different groove depths and groove widths. Specifically, the groove depth and groove width in the sub-groove 13A of the first chip discharge groove 8A are made larger than the groove depth and groove width in the sub-groove 13B of the second chip discharge groove 8B, Thereby, the groove width of the entire first chip discharge groove 8A is larger than the groove width of the entire second chip discharge groove 8B.

Each chip discharge groove 8 has a convex V-shape that is located between the main groove 12 and the sub-groove 13 and extends radially outward, and is twisted along each chip discharge groove 8. An extending ridge line portion 14 is formed.
Such a chip discharge groove 8 is formed on the outer periphery of the cutting blade portion 3 of the head main body 1, and its base end portion (round-up portion) extends over the outer periphery of the latching portion 4 of the head main body 1. .

  1 to 3, a concave gash 9 is formed at the tip of each chip discharge groove 8. A bottom edge 7 having a rake face as the wall surface is formed on each of the ridges on the tip side of the wall surface facing the tool rotation direction T of each gasche 9. The bottom blade 7 extends slightly inclined so as to gradually recede toward the base end side as it goes radially inward.

As shown in FIG. 3, the plurality of bottom blades 7 are formed so as to have a radial shape about the axis O on the tip surface of the cutting blade portion 3. Among these bottom blades 7, the bottom blade 7 connected to the outer peripheral blade 6 of the first chip discharge groove 8A is longer than the bottom blade 7 connected to the outer peripheral blade 6 of the second chip discharge groove 8B in the radial direction. Is getting longer.
Further, the bottom blade 7 and the outer peripheral blade 6 are smoothly connected by a corner blade 11 having a curved shape so as to protrude toward the radially outer side and the distal end side.

In FIG. 1 and FIG. 2, the latching portion 4 has a substantially circular outer shape substantially the same as or slightly smaller than the outer diameter of the outer peripheral blade 6 of the cutting blade portion 3, and chips are discharged from the cutting blade portion 3. It is formed so as to include a rounded-up portion toward the outer peripheral side of the base end of the groove 8. The outer periphery of the hook portion 4 is located at the base end portion of the outer periphery of the head body 1.
A pair of hooking surfaces 15 that are parallel to the axis O and parallel to each other are cut out from the hooking portion 4 on both sides of the hooking portion 4 so as to cut out the outer peripheral surface of the hooking portion 4. Are formed at equal intervals from the axis O.

As shown in FIGS. 2 and 4, the pair of latching surfaces 15 are formed by cutting the outer periphery of the latching portion 4 into a flat shape, and the base ends along the axis O direction on the outer periphery of the head body 1. The portion (that is, the hooking portion 4) is disposed backward (placed back to back) across the axis O. These retaining surfaces 15 are arranged on the base end side of the chip discharge groove 8 and the outer peripheral blade 6 on the outer periphery of the head main body 1.
The latching surface 15 is formed on the outer periphery of the latching portion 4 so as to form a substantially rectangular shape when the latching surface 15 is viewed from the side as viewed from the side shown in FIG.

  Of the pair of hooking surfaces 15, at least one hooking surface 15 is connected to the base end portion of the second chip discharge groove 8B having a narrow width. In the example of the present embodiment, as shown in FIG. 4, a total of four chip discharge grooves 8 are provided on the outer periphery of the head body 1, and two first chip discharge grooves 8 </ b> A and two The second chip discharge grooves 8B are arranged in the back direction so as to be opposite to each other with respect to the axis O (180 ° rotationally symmetrical position). It is connected with the base end part of a pair of 2nd chip | tip discharge groove | channel 8B, respectively.

  In FIG. 1, the proximal end portion of the second chip discharge groove 8 </ b> B is opened adjacent to the distal end side in the surface of the hooking surface 15. That is, in this side view, of the four sides forming the outer shape of the latching surface 15, one side located at the tip is directed toward the base end so as to correspond to the rounded shape of the base end of the second chip discharge groove 8B. (Within the surface of the latching surface 15) is a concave curve, and the other three sides are linear. As a result, the latching surface 15 has a U shape or a U shape in the side view of FIG.

Further, both end edges (a pair of sides located at both ends in the circumferential direction) 15a along the circumferential direction of the hooking surface 15 extend in a ridge shape on the outer periphery of the head body 1 without being cut out by the chip discharge groove 8. Yes. In the example of the present embodiment, these end edges 15 a extend on the outer periphery of the latching portion 4 so as to be parallel to the axis O and form a linear ridgeline.
In addition, a wall surface 16 is provided from one side located at the base end of the latching surface 15 so as to be perpendicular to the axis O toward the radially outer side and facing the leading end side.
In addition, it is preferable that the coating film is coat | covered on the surface of the cutting blade part 3 and the latching | locking part 4 of the head main body 1. FIG.

  The attachment portion 5 has a truncated cone shape with the axis O having a smaller diameter than the hook portion 4 and decreasing in outer diameter toward the proximal end. An annular step surface 17 that faces the base end side between the latching portion 4 and the attachment portion 5 is a plane perpendicular to the axis O. Further, a mounting hole (not shown) centering on the axis O is formed from the base end surface of the mounting portion 5 to the middle of the latching portion 4 and the cutting blade portion 3 from the distal end side.

  The connecting member 2 includes a shaft portion (not shown) that is inserted into and fixed to the mounting hole, and a screw portion 2 a that is a male screw portion that is larger in diameter than the shaft portion and smaller in diameter than the base end surface of the mounting portion 5. ing. The shaft of the connecting member 2 is fixed to the mounting hole by, for example, forming a through hole along the axis O from the shaft to the screw portion 2a in the connecting member 2, and the shaft at the tip of the screw portion 2a. After making the step surface with the part contact the base end face of the attachment part 5 and inserting the shaft part into the attachment hole, a punch is driven into the through hole from the base end side, and the shaft part is plastically deformed. This is performed by expanding the diameter and joining the mounting hole.

  The replaceable cutting head 10 configured as described above has a head main body 1 detachably attached to a tip end portion of a cylindrical tool main body by a connecting member 2, and a work material by a cutting edge portion 3 of the head main body 1. Cutting is performed. The tip of the tool body has a contact surface with which the stepped surface 17 of the head body 1 can contact, a tapered hole that opens to the contact surface and gradually decreases in diameter toward the base end side of the tool body. A female screw portion formed at the bottom of the taper hole is formed. The screw portion 2a, which is the male screw portion, is screwed into the female screw portion to closely attach the attachment portion 5 to the taper hole and the step surface 17 Is brought into contact with the contact surface, whereby the replaceable cutting head 10 is fixed to the tip of the tool body.

  When the screw portion 2a of the connecting member 2 is screwed into the female screw portion of the tool body as described above, or when the screw portion 2a is loosened when the replaceable cutting head 10 is removed from the tool body, a pair of retaining surfaces is used. By engaging a pair of engagement surfaces of a U-shaped opening of a work tool such as a wrench or spanner with 15, the work tool is hooked on the hook portion 4, and the connecting member 2 and the head body 1 are engaged. Is rotated around the axis O.

  According to the exchangeable cutting head 10 of the present embodiment described above, the pair of hooking surfaces 15 on which the working tool is hooked (locked) are arranged on the back of the base end portion of the outer periphery of the head body 1. Of the first and second chip discharge grooves 8A and 8B that are different from each other and have different circumferential widths, the widths of the second chip discharge grooves 8B that are made narrower. Since at least one of the retaining surfaces 15 is continuous with the base end portion (rounded-up portion), the following effects are achieved.

That is, as a first effect, it is easy to ensure the rigidity balance of the head main body 1 evenly in the circumferential direction.
Specifically, among the first and second chip discharge grooves 8A and 8B having different circumferential widths, the head body 1 in which the first chip discharge groove 8A having a wider circumferential width is formed. The circumferential portion is likely to be less rigid than portions other than the circumferential portion. Further, the circumferential direction portion of the head body 1 where the retaining surface 15 formed so as to cut out the outer periphery of the head body 1 in a planar shape is the circumferential direction of the head body 1 where the retaining surface 15 is not formed. Rigidity tends to be lower than that of the part.
Therefore, in the present embodiment, the hook surface 15 is continuously provided at the base end portion of the second chip discharge groove 8B having a narrow width, so that a portion in which the circumferential rigidity is significantly reduced in the head body 1 is generated. It was made possible to suppress this surely.

Specifically, at the base end portion of the head body 1 (in this embodiment, the central portion along the direction of the axis O of the latching portion 4), as shown in FIG. 6 which is a CC cross section of FIG. The rigidity of the head main body 1 is reduced along the direction in which the hooking surface 15 is turned back (the left-right direction in FIG. 6), while the portion located on the front end side from the base end portion of the head main body 1 (this embodiment) In the embodiment, at the front end side portion of the latching portion 4 with respect to the center portion, as shown in FIG. 5 which is a BB cross section of FIG. Specifically, the first chip discharge grooves 8A face each other, and the rigidity is reduced along the vertical direction in FIG.
Here, the imaginary circle indicated by the two-dot chain line in FIGS. 5 and 6 represents an inscribed circle that passes through a portion having the smallest outer diameter in each cross section of the head body 1, and is shown in FIG. 6, the distance between the pair of hooking surfaces 15 (in FIG. 6) is larger than the distance between the pair of first chip discharge grooves 8 </ b> A (the distance between the outer circumferences in the vertical direction in FIG. 6). The distance between the outer peripheries in the left-right direction is small. On the other hand, in the part located in the front end side from the said base end part of the head main body 1 shown by FIG. 5, compared with the distance (distance between the outer periphery of the left-right direction in FIG. 5) between a pair of 2nd chip discharge grooves 8B. The distance between the pair of first chip discharge grooves 8A (the distance between the outer circumferences in the vertical direction in FIG. 5) is reduced.

  As described above, since the portion of the head body 1 having low rigidity is distributed in the circumferential direction at each part in the direction of the axis O, the strength balance of the head body 1 can be easily ensured evenly in the circumferential direction as a whole tool. . Thereby, it can suppress that chatter vibration etc. arise at the time of cutting.

Here, as a reference example having a technical idea different from that of the present invention, FIGS. 7 to 9 show a configuration in which a pair of hooking surfaces 15 are connected to the base end portion of the first chip discharge groove 8A.
In this reference example, at the base end portion of the head main body 1 shown in FIG. 9, a pair of latches is compared with the distance between the pair of second chip discharge grooves 8B (the distance between the outer circumferences in the left-right direction in FIG. 9). The distance between the surfaces 15 (the distance between the outer circumferences in the vertical direction in FIG. 9) is small. Further, even in a portion of the head main body 1 shown in FIG. 8 that is located on the distal end side with respect to the base end portion, compared to the distance between the pair of second chip discharge grooves 8B (distance between the outer circumferences in the horizontal direction in FIG. 8). The distance between the pair of first chip discharge grooves 8A (the distance between the outer circumferences in the vertical direction in FIG. 8) is small.
In such a configuration, the circumferential portion having low rigidity in the head main body 1 is continuous in the direction of the axis O, and chatter vibration or the like may easily occur during cutting.

In addition, as a second effect according to the embodiment of the present invention, it is possible to improve the chip discharge performance even in the second chip discharge groove 8B having a narrow base end portion.
That is, since the latching surface 15 formed so as to cut out the outer periphery of the head main body 1 is connected to the base end portion (round-up portion) of the second chip discharge groove 8B. It is easy to secure a space between 15 and the work surface of the work material cut by the replaceable cutting head 10. In other words, it is possible to avoid a situation where the hooking surface 15 acts like a chip pocket and the chips flowing in the second chip discharge groove 8B are clogged by the raised portion of the groove, and the chip discharge performance is improved. To do.

A third effect is to stably perform the operation of attaching and detaching the head body 1 to and from the tool body while reducing the manufacturing cost by reducing the length of the head body 1 along the axis O direction. Can do.
That is, the latching surface 15 on which the work tool is latched is arranged at the proximal end portion of the outer periphery of the head main body 1 and is connected to the proximal end portion of the chip discharge groove 8. Is different (for example, as in Japanese Patent Application Laid-Open No. 2010-284752), compared with a configuration in which the hooking surface 15 and the chip discharge groove 8 are arranged with an interval in the direction of the axis O, the direction of the axis O of the head body 1 It is easy to keep the length along the line small.

  More specifically, the replaceable cutting head 10 has a head body 1 made of an expensive material such as a cemented carbide, as well as a cutting blade 3 and a hook, as compared with a tool body that is easy to make common parts and easy to manufacture at low cost. Since the manufacturing process is complicated, for example, the stopper 4 is coated, and a plurality of types of cutting blades are prepared according to the type of the tool, the head main body as in this embodiment is prepared. By keeping the length along the direction of one axis O small, manufacturing costs are reduced and component management is facilitated.

  Further, the chip discharge groove 8 connected to the latching surface 15 on the outer periphery of the head main body 1 is the second chip discharge groove 8B having a narrow base end portion. It is suppressed that both edge (edge) 15a of the circumferential direction of the stop surface 15 is notched. That is, according to the present embodiment, it is easy to ensure a large contact (contact) length along the circumferential direction between the hooking surface 15 and the work tool hooked on the hooking surface 15. Therefore, it becomes easy to stably rotate the exchangeable cutting head 10 with the work tool, and the workability of attaching / detaching the exchangeable cutting head 10 to / from the tool body is improved.

  As described above, according to the exchangeable cutting head 10 of the present embodiment, chatter vibration and the like during cutting can be suppressed, and chip discharge performance can be improved even in the chip discharge groove 8B having a narrow width. The processing accuracy and processing stability can be sufficiently increased, and the head body 1 can be stably rotated by the working tool when the head body 1 is attached to and detached from the tool body while the manufacturing cost is reduced by making the head body 1 small. It is possible.

  Further, in the present embodiment, both end edges 15 a along the circumferential direction of the latching surface 15 extend in a ridge line shape on the outer periphery of the head body 1 without being cut out by the chip discharge groove 8. And the contact (abutment) length along the circumferential direction with the work tool hooked on the hooking surface 15 can be reliably ensured to be large, and the above-described effect, that is, the replaceable cutting head 10 can be secured by the work tool. The effect that it becomes easy to rotate stably and the workability of attaching and detaching the exchangeable cutting head 10 with respect to the tool body is enhanced becomes more remarkable.

  Further, in the present embodiment, the chip discharge grooves 8 are evenly formed on the outer periphery of the head main body 1, and the pair of hooking surfaces 15 of the second chip discharge grooves 8 </ b> B disposed backward with the axis O interposed therebetween. Since it is connected to the base end portions, the above-described action is obtained by both of the pair of hooking surfaces 15, and the effect becomes more remarkable.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the replaceable cutting head 10 has a radius end mill shape. However, the present invention is not limited to this. That is, the exchangeable cutting head of the present invention can be used for various types of turning processing such as end milling, drilling, and reamer processing, and is not limited to the shape described in the above embodiment.

  In addition, the chip discharge groove 8 and the outer peripheral blade 6 are gradually twisted and extended toward the rear in the tool rotation direction T from the distal end of the cutting blade portion 3 toward the proximal end side. is not. That is, the chip discharge groove 8 and the outer peripheral edge 6 only need to extend along the direction of the axis O, and are gradually twisted toward the front in the tool rotation direction T from the distal end of the cutting edge portion 3 toward the proximal end side. It may extend or may extend parallel to the axis O.

  Further, the first chip discharge groove 8A and the second chip discharge groove 8B having different circumferential widths at least at the base end portion along the axis O direction are alternately arranged in the circumferential direction on the outer periphery of the head body 1. However, the present invention is not limited to this. That is, the number of the chip discharge grooves 8 is not limited to the even number such as the above-described four items, and may be an odd number such as the three items. In this case, at least one latching surface 15 of the pair of latching surfaces 15 is connected to the base end portion of the narrow second chip discharge groove 8B, thereby obtaining the above-described effects. .

  Further, three or more kinds of the chip discharge grooves 8 may be provided so that the widths in the circumferential direction are different from each other at least at the base end portion (rounded-up portion) along the axis O direction. In this case, the chip discharge groove 8 having the largest groove width in the raised portion is the first chip discharge groove 8A, and the other chip discharge groove 8 is the second chip discharge groove 8B, and the latching surface 15 Is continuously provided at the base end of the second chip discharge groove 8B.

  Moreover, in the example of the above-described embodiment, as shown in FIGS. 1 and 4, the both ends 15 a along the circumferential direction of the pair of hooking surfaces 15 are not cut into the chip discharge groove 8. Although it extends in the shape of a ridge on the outer periphery of 1, it is not limited to this. That is, of the pair of latching surfaces 15, both end edges 15 a along the circumferential direction of at least one latching surface 15 extend in a ridge shape on the outer periphery of the head body 1 without being cut out by the chip discharge groove 8. In this way, the above-described effects can be obtained.

  In addition, in the range which does not deviate from the meaning of this invention, you may combine each structure (component) demonstrated by the above-mentioned embodiment, a modified example, a note, etc., addition of a structure, omission, substitution, others It can be changed. Further, the present invention is not limited by the above-described embodiments, and is limited only by the scope of the claims.

1 Head body 6 Peripheral blade (cutting blade)
DESCRIPTION OF SYMBOLS 8 Chip discharge groove 8A 1st chip discharge groove 8B 2nd chip discharge groove 10 Replaceable cutting head 15 Latch surface 15a Edge O along the circumferential direction of latch surface

Claims (2)

An exchangeable cutting head having a head body that is detachably attached by screwing to the tip of a tool body rotated about an axis,
On the outer periphery of the head body,
A plurality of chip discharge grooves extending along the axial direction;
A cutting blade extending along the chip discharge groove;
A pair of hooking surfaces that are formed so as to cut out the outer periphery of the head main body in a planar shape, and are arranged in the back direction across the axis at the base end along the axis.
In the plurality of chip discharge grooves,
A first chip discharge groove;
A second chip discharge groove having a narrower width along the circumferential direction around the axis than the first chip discharge groove at the base end portion along at least the axial direction, and
Of the pair of hooking surfaces, at least one hooking surface is connected to a base end portion of the second chip discharge groove,
The head body is formed with a latching portion in which the pair of latching surfaces are formed,
The latching portion has the same diameter or a small diameter as the outer diameter of the cutting blade,
The second chip discharge groove is
The main groove,
A sub-groove that is adjacent to the front of the main groove in the tool rotation direction and has a narrower circumferential width than the main groove;
Of the pair of latching surfaces, at least one latching surface has both edges along the circumferential direction extending in a ridge shape on the outer periphery of the head body without being cut into the main groove. Replaceable cutting head. The exchangeable cutting head according to claim 1,
The replaceable cutting head according to claim 1, wherein the chip discharge groove is formed in an odd number on an outer periphery of the head body.

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