WO2017111001A1

WO2017111001A1 - Tip for cutting tool, cutting tool, and method for manufacturing same

Info

Publication number: WO2017111001A1
Application number: PCT/JP2016/088347
Authority: WO
Inventors: 寛久石; 誠君山; 吉紘光前
Original assignee: 京セラ株式会社
Priority date: 2015-12-25
Filing date: 2016-12-22
Publication date: 2017-06-29
Also published as: JP6723010B2; JP2017113850A

Abstract

A tip for a cutting tool, the tip having a base material that has an upper surface, a lower surface, and an outer peripheral surface positioned between the upper surface and the lower surface. A gate mark is positioned at a site surrounded by the outer peripheral surface, at a height in between the upper surface and the lower surface of the base material.

Description

Cutting tool tip, cutting tool, and manufacturing method thereof

This aspect relates to a chip constituting a blade part of a cutting tool, a cutting tool, and a manufacturing method thereof.

A so-called insert (throw away tip) is known which is mounted on an insert type (blade tip exchange type) cutting tool to constitute a blade part. Such a cutting tool tip (hereinafter, simply referred to as “chip”) generally includes a raw material powder made of a relatively hard material and a raw material powder that becomes a binder phase component of the hard raw material powder. The mixture is pressed by a mold and molded, and then fired.

Japanese Laid-Open Patent Publication No. 4-283209 (Patent Document 1) proposes forming the raw material by injection molding in which the raw material is injected into the internal space of the mold instead of the press. The inner space of the mold generally includes a cavity (product part) for forming a product (here, a chip), a runner for supplying a raw material to the cavity, and the like. The opening located at the boundary between the cavity and the runner is called a gate. In Patent Document 1, the gate is located on the side surface of the chip.

As described above, since the inner space of the mold includes not only the cavity but also the runner, the molded product obtained by molding the raw material by injection molding is not only the part that becomes the chip, but also the raw material in the runner It also includes unnecessary portions formed by. This unnecessary portion is removed from the portion that becomes the cutting tool tip by cutting or the like after the molded body is taken out of the mold. The removal trace (gate trace) is accompanied by, for example, a convex portion, a concave portion or a combination thereof and / or a surface roughness.

A cutting tool tip according to an aspect includes a base material having an upper surface, a lower surface, and an outer peripheral surface positioned between the upper surface and the lower surface, and the tip between the upper surface and the lower surface of the base material. A gate mark is located at a height and surrounded by the outer peripheral surface.

The perspective view which shows the insert type cutting tool which concerns on 1st Embodiment. The perspective view which shows the chip | tip for cutting tools of the cutting tool of FIG. 3A is a cross-sectional view taken along line IIIa-IIIa in FIG. 2, FIG. 3B is an enlarged view of region IIIb in FIG. 3A, and FIG. 3C is a plan view schematically showing mounting holes. . The flowchart which shows the manufacturing method of the chip | tip for cutting tools. 5 (a) to 5 (e) are schematic diagrams for explaining the outline of the procedure of the method for manufacturing the cutting tool tip. The flowchart which shows the method of the injection molding in the manufacturing method of the chip | tip for cutting tools. FIGS. 7A to 7D are schematic views for explaining the injection molding procedure of FIG. Sectional drawing corresponding to Fig.3 (a) which shows the shaping | molding die used by the injection molding of FIG. The top view of the shaping | molding die of FIG. 10A is a perspective view showing a cutting tool tip according to the second embodiment, FIG. 10B is a cross-sectional view showing a mold for the cutting tool tip of FIG. 10A, and FIG. FIG. 11C is a plan view showing a part of the mold shown in FIG. FIG. 11A is a perspective view showing a cutting tool tip according to the third embodiment, FIG. 11B is a cross-sectional view showing a forming die for the cutting tool tip of FIG. FIG. 12C is a plan view showing a part of the mold shown in FIG. 12 (a) is a perspective view showing a cutting tool tip according to the fourth embodiment, FIG. 12 (b) is a cross-sectional view showing a forming die for the cutting tool tip of FIG. 12 (a), and FIG. FIG. 13C is a plan view showing a part of the mold shown in FIG. FIG. 13A is a cross-sectional view showing a part of an insert type cutting tool according to the fifth embodiment, and FIG. 13B shows a mold for a cutting tool tip of the cutting tool of FIG. 13A. Cross-sectional view, FIG. 13C is a cross-sectional view showing a molded body formed by the mold shown in FIG. 13B, and FIG. 13D is a cutting tool tip formed from the molded body shown in FIG. 13C. FIG.

(How to use terms)
In the following description, terms relating to cutting tools and the like are used as follows.

The blade portion is used as a term indicating a relatively small portion (for example, a part of an insert) including a rake face, a flank face, and a cutting edge.

切 The cutting edge refers to one or more blades that are used simultaneously during cutting. Therefore, for example, the cutting blade portion may be composed of one blade portion, or may be composed of two blade portions adjacent to each other via a corner (nose).

The cutting edge is used as a term indicating the ridge line between the rake face and the flank face. However, the actual cutting blade is not a line microscopically as the term “cutting blade roundness” exists, and the cutting blade has an area or a volume as long as it is.

The rake face and flank face mainly refer to the rake face and flank face closest to the cutting edge. Note that the flank may or may not include a so-called margin.

The hole may be either a through hole or a recess. In addition, when the hole portion is referred to as an opening portion, the portion of the hole portion on the surface where the hole portion is provided (inlet of the hole portion) is indicated.

<First Embodiment>
(Configuration of cutting tool)
FIG. 1 is a perspective view showing an insert-type cutting tool 1 according to the first embodiment.

The cutting tool 1 is a substantially shaft-shaped member that is attached to and detached from a holder 3 (shank) attached to a machine tool and a tip end side (left side of the paper) of the holder 3 and actually contacts a work piece. And one or more (three in the example of FIG. 1) chips 5 for cutting the work. In the example shown in the drawing, the cutting tool 1 is an end mill, and is capable of cutting a workpiece on the tip surface and the outer peripheral surface of the tip by being rotated about an axis.

The mounting of the chip 5 to the holder 3 is performed, for example, by screwing the screw 7 inserted through the chip 5 into a female screw portion (not shown) hidden in the chip 5. The holder 3 is formed with, for example, a recess 3r composed of a plurality of surfaces with which a plurality of surfaces (for example, one main surface and two side surfaces) of the chip 5 abut. The chip 5 is positioned by contacting the surface of the recess 3r.

(Chip configuration)
FIG. 2 is a perspective view showing the chip 5. FIG. 3A is a cross-sectional view taken along line IIIa-IIIa in FIG.

In FIG. 2 and FIG. 3A and the like, an orthogonal coordinate system xyz defined and fixed to the chip 5 is attached. In the following description, directions may be described with reference to this coordinate system. Any direction of the chip 5 may be a vertical direction or a horizontal direction, and the dimension in the z-axis direction may be relatively large. However, the z-axis direction is referred to as a vertical direction or a thickness direction. is there. Further, when the chip 5 is simply referred to as a plan view, it refers to viewing in the z-axis direction.

The chip 5 includes a base material 6 that is integrally formed and forms the shape of the chip 5. For example, the chip 5 includes only the base material 6 or includes the base material 6 and a coating layer (not shown) that covers the base material 6. When the coating layer is provided, the coating layer may cover the entire surface of the base material 6 or may cover only a part of the base material 6. The coating layer is relatively thin and has almost no influence on the shape of the chip 5 macroscopically.

For example, various known materials may be applied to these materials. For example, the material of the base material 6 is cemented carbide, diamond sintered body, CBN (Cubic Boron Nitride) sintered body, narrow speed ceramic, cermet, or high speed tool steel (powder high speed) formed by powder metallurgy. is there. The material of the coating layer is, for example, diamond-like carbon, titanium nitride, titanium nitride carbide, titanium aluminum nitride, titanium carbide, chromium nitride, or aluminum oxide.

The chip 5 is formed, for example, in a substantially rectangular parallelepiped shape, and is located between the pair of main surfaces 9 (upper surface and lower surface) and the pair of main surfaces 9 and connects the pair of main surfaces 9. It has four side surfaces 11. In addition, all the side surfaces 11 whole may be called the outer peripheral surface 12. The dimensions of the chip 5 may be set as appropriate.

The side surface 11 positioned on the long side in plan view is, for example, generally bulging outward as a whole. On the other hand, the side surface 11 located on the short side in the plan view is generally recessed, for example, so that the center side in the thickness direction is lowest as a whole. Note that these shapes may be appropriately set from various viewpoints such as securing strength and securing a flank.

(Configuration of cutting edge)
The tip 5 has, for example, a plurality of cutting edge portions 14 that protrude in the thickness direction (z-axis direction) of the tip 5 at the outer peripheral edge of the main surface 9.

The cutting edge portion 14 is provided, for example, on each of the pair of main surfaces 9, and is provided on each of the main surfaces 9 at two corner portions positioned on one diagonal line. In plan view, the diagonal line provided with the cutting edge portion 14 on the one main surface 9 side intersects with the diagonal line provided with the cutting edge portion 14 on the other main surface 9 side. Therefore, the chip 5 can be used four times by rotating 180 ° around the z axis and / or rotating 180 ° around the x axis.

Each cutting edge 14 is, for example, a long edge 13L and a short edge 13S (hereinafter simply referred to as “blade 13”, which are not directly distinguished from each other) that are directly involved in the cutting of the work material. have.

These blade portions 13 are located at corners (ie, intersecting ridge lines) between the main surface 9 and the side surface 11. The long edge part 13L and the short edge part 13S are connected with corners 21 (nose) at the corners of the long side and the short side in plan view.

Each blade portion 13 is a portion where the rake face 15 through which chips generated by cutting flow, the flank face 17 which escapes to avoid unnecessary contact with the finished surface, and the rake face 15 is connected to the flank face 17. And a cutting edge 19.

The blade portion 13 is formed, for example, so as to protrude in the thickness direction (z-axis direction) with respect to the center side of the main surface 9. Specifically, for example, the rake face 15 is continuous to the center side of the main surface 9 and is formed to rise in the thickness direction from the main surface 9 on the center side. For example, the flank 17 is continuous with the side surface 11 and extends beyond the central main surface 9 in the thickness direction. Further, for example, the cutting edge 19 has a height from the center side of the main surface 9 that is higher toward the corner 21 side.

In the longitudinal section as shown in FIG. 3A, the presence / absence of the rake face 15 and the flank face 17 with respect to the thickness direction (z-axis direction), the inclination direction, and the inclination angle may be set as appropriate. In the illustrated example, the flank 17 is inclined with respect to the thickness direction so that the flank 17 is located closer to the center of the main surface 9 toward the cutting edge 19 side. Unlike the illustrated example, for example, the flank 17 may be parallel to the thickness direction, or may be inclined in the thickness direction so as to be positioned on the outer peripheral edge side of the main surface 9 toward the cutting edge 19 side. .

As described above, in the present embodiment, since the blade portion 13 protrudes from the main surface 9, the tip 5 includes the base portion 23 having the main surface 9 and the side surface 11, and the blade portion 13 protruding from the base portion 23. May be perceived as having Further, since the blade portion 13 protrudes from the main surface 9, in the present embodiment, it may be considered that the cutting blade 19 is formed on at least one of the upper end portion and the lower end portion of the outer peripheral surface 12.

(Configuration of mounting holes)
The chip 5 has a hole. The hole is, for example, a mounting hole 25 made of a through hole and through which a fixing member such as the screw 7 is inserted. As shown in FIG. 3A, the attachment hole 25 has a receiving portion 27 located on the opening 26 side (main surface 9 side) and an insertion portion 29 located in the back thereof. The receiving portion 27 is a portion that receives the screw head 7 b of the screw 7 and abuts the screw head 7 b, and the insertion portion 29 is a portion through which the male screw portion 7 a of the screw 7 is inserted. The receiving portions 27 are provided on both sides of the mounting hole 25 in the penetrating direction.

In the present embodiment, the mounting hole 25 is a through hole provided from one side of the pair of main surfaces 9 to the other, and the opening 26 is located on the main surface 9. Is not limited to such a configuration. For example, the hole may be configured such that the opening 26 is located on the side surface 11. Specifically, the mounting hole 25 may be configured by a through hole provided from one side of the side surface 11 located on the opposite side to the other side.

The receiving portion 27 extends, for example, while reducing the diameter from the main surface 9 side to the insertion portion 29 side. The insertion portion 29 is a portion having the smallest diameter in the attachment hole 25. The maximum diameter of the receiving portion 27 is equal to or larger than the diameter of the screw head 7b. Further, the diameter of the insertion portion 29 (minimum diameter of the receiving portion 27) is smaller than the diameter of the screw head 7b and larger than the diameter of the male screw portion 7a.

(Gate trace)
FIG. 3B is an enlarged view of region IIIb in FIG. FIG. 3C is a plan view showing the attachment hole 25.

The gate mark 30 in the chip 5 is a height between the pair of main surfaces 9 in the base material, and is located at a portion surrounded by the outer peripheral surface 12. In the present embodiment, the gate mark 30 is located in the mounting hole 25. That is, as will be described in detail later, the base material 6 of the chip 5 is formed by injection molding in which a raw material is injected into a mold, and the cavity that forms the base material 6 of the mold is formed in the mounting hole 25. Raw material is injected from the gate located.

Specifically, the gate mark 30 is located on the inner surface of the insertion portion 29 in the mounting hole 25. A predetermined margin (gap) is interposed between the inner surface of the insertion portion 29 and the male screw portion 7 a of the screw 7. Therefore, the screw 7 fixes the chip 5 to the holder 3 in a non-contact state with respect to the gate mark 30. Further, the screw 7 (screw head 7b) is engaged with the base material 6 directly or indirectly through the coating layer in the axial direction and / or the radial direction of the screw 7 outside the gate mark 30. Become.

The size of the gate mark 30 may be set as appropriate. For example, as shown in FIG. 3B, the gate mark 30 is formed over the entire penetrating length (z-axis direction) of the insertion portion 29 in the cross section (vertical cross section) including the axis of the mounting hole 25. Yes. However, the gate mark 30 may be formed only in a part of the penetration length of the insertion portion 29. When it is formed only in a part of the penetration length of the insertion portion 29, the possibility that the screw head 7b abuts on the gate mark 30 can be reduced. Therefore, the screw head 7b can be stably brought into contact with the receiving portion 27.

Further, for example, as shown in FIG. 3C, the gate trace 30 is formed over the entire circumference of the insertion portion 29 and is annular in plan view. However, the gate trace 30 may be formed only in a part of the insertion portion 29 in the circumferential direction. For example, although not particularly illustrated, the position and / or size of the gate mark 30 in the z-axis direction is constant over the entire circumference of the insertion portion 29. However, the position and / or size of the gate mark 30 in the z-axis direction may vary depending on the circumferential position of the insertion portion 29.

In the present embodiment, the cutting edge portion 14 is located at the end of the chip 5 in the thickness direction (z-axis direction) in the longitudinal section as shown in FIG. Therefore, considering the gate mark 30 as a reference, the cutting edge portion 14 is provided at a position farthest from the gate mark 30 in the axial direction of the attachment hole 25 (in another aspect, the z-axis direction).

In addition, since the pair of receiving portions 27 are inclined in the longitudinal section, the inner surface of the insertion portion 29 intersects the direction in which the cutting blade 19 of the cutting blade portion 14 projects (generally the z-axis direction) ( For example, it protrudes in a direction (y-axis direction) orthogonal. As a result, the gate mark 30 formed on the inner surface of the insertion portion 29 protrudes in a direction intersecting the direction in which the cutting edge 19 of the cutting edge portion 14 protrudes.

It should be noted that the direction in which the cutting edge 19 of the cutting edge portion 14 protrudes may be defined by the direction in which an intermediate line between the flank 15 and the rake face 17 (which may be an approximate straight line in the case of a curve) extends. Similarly, the direction in which the gate mark 30 (the inner surface of the insertion portion 29) protrudes may also be defined by the direction in which the middle line of the pair of receiving portions 27 extends.

The gate trace 30 is generally visible. This is because, for example, depending on the method for removing unnecessary parts formed on the runner, etc., the surface from which the unnecessary parts are removed rises slightly from the surrounding surface due to the force applied during removal. is there. And / or, for example, the surface from which unnecessary portions have been removed (for example, a cut surface) has a surface roughness different from that of the surface around the adjacent region in which the inner surface of the mold is transferred (generally, This is because the surface roughness of the cut surface is larger) and, in turn, the way in which the light is reflected is different.

3B and 3C schematically show that the surface roughness of the gate mark 30 is larger than the surface roughness of the other surface (the surface on which the inner surface of the mold is transferred) ( Somewhat exaggerated). Note that the difference in surface roughness between the gate trace 30 and other surfaces tends to appear in the appearance of the surface (for example, gloss) due to the difference. Therefore, for example, when determining whether or not the surface roughness of the two is different, it is often unnecessary to compare the surface roughness of the two until the arithmetic average roughness or the like is measured.

When the chip 5 is composed only of the base material 6, the gate mark 30 is exposed in the mounting hole 25. When the surface of the base material 6 is covered with a coating layer (not shown), the gate mark 30 may be covered with the coating layer, or may be exposed in the mounting hole 25 without being covered. When the gate trace 30 is covered with the coating layer, the thickness of the coating layer may be a thickness at which the gate trace 30 cannot be seen, or a thickness at which the gate trace 30 can still be seen.

(Chip manufacturing method)
FIG. 4 is a flowchart showing a method for manufacturing the chip 5. FIG. 5A to FIG. 5E are schematic diagrams for explaining the outline of the procedure of the manufacturing method of the chip 5. The manufacturing method proceeds in order from FIG. 5 (a) to FIG. 5 (e).

First, the raw material 31 of the chip 5 is prepared as indicated by reference numeral S301 in FIG. 4 and as shown in FIG. Specifically, for example, a relatively hard raw material powder that is a main component, a raw material powder that is a binder phase component of this hard raw material powder, imparts fluidity to these raw material powders, and retains shape retention after molding. Mixing of organic substances such as a binder for imparting is performed.

Taking the case where the chip 5 is made of cemented carbide as an example, the raw material powder includes tungsten carbide as a main component, cobalt as a binder component, tantalum carbide and titanium carbide. Examples of the binder or a role similar to the binder include paraffin or an appropriate type of resin. As described above, the tip 5 is not limited to the cemented carbide.

Next, as indicated by reference numeral S302 in FIG. 4 and as shown in FIG. 5B, the raw material 31 of the chip 5 is injected and filled into the molding die 33. That is, the process indicated by reference numeral S302 in FIG. 4 is a molding process for forming a molded body to be a cutting tool chip. The shape in the molding die 33 is substantially the same as that of the molded body to be the chip 5. Therefore, when the injected raw material 31 is solidified in the molding die 33, a molded body 35 (FIG. 5C) having a shape substantially similar to that of the chip 5 is formed.

Next, as indicated by reference numeral S <b> 303 in FIG. 4 and as shown in FIG. 5C, an unnecessary portion as the chip 5 is removed from the molded body 35 taken out from the molding die 33. The unnecessary portion is, for example, a portion solidified by a so-called sprue and runner (described later). The removal may be performed by an appropriate method, for example, by cutting the gate 53 by the cutter 37.

Next, as shown in FIG. 4 by reference numeral S304 and as shown in FIG. 5D, the molded body 35 is fired (a heat treatment step is performed). As a result, a sintered body 39 (FIG. 5E) to be the chip 5 is formed. At this time, the binder added to impart fluidity to the raw material 31 evaporates or burns and is removed from the sintered body 39.

Then, as indicated by reference numeral S305 in FIG. 4 and as shown in FIG. 5 (e), the cutting edge of the sintered body 39 is ground or polished (honed) to adjust the roundness of the cutting edge. Thereby, the chip 5 is obtained. Honing is performed, for example, by sandblasting as illustrated in FIG.

Note that the above procedure is merely an outline of an example of the procedure, and may be modified as appropriate. For example, the removal of unnecessary portions (FIG. 5 (c)) may be after firing (FIG. 5 (d)).

(injection molding)
FIG. 6 is a flowchart showing a molding process by injection indicated by S302 in FIG. 7 (a) to 7 (d) are schematic diagrams for explaining the injection molding procedure of FIG. 5 (b). Injection molding proceeds in order from FIG. 7 (a) to FIG. 7 (d).

First, as indicated by reference numeral S401 in FIG. 6 and as shown in FIG. 7A, the mold 33 composed of a plurality of divided molds (41: 41A to 41C) is closed. The split type here includes, for example, a core or a slide core in addition to a fixed type and a movable type.

By closing the mold, a space surrounded by a plurality of divided molds 41 is formed as shown in FIG. At this time, an appropriate gas (for example, air) exists in the mold 33.

After the mold clamping, the injection is performed by the injection device (in a narrow sense) as indicated by reference numeral S402 in FIG. 6 and as shown in FIG. 7 (c). Specifically, the raw material 31 in the sleeve 43 (cylinder) communicating with the molding die 33 is pushed into the molding die 33 by the plunger 45 in the sleeve 43. The injection speed may be set as appropriate, and appropriate shift control may be performed.

In the process in which the raw material 31 is injected into the mold 33, the gas in the mold 33 is appropriately discharged to the outside of the mold 33.

FIG. 7C schematically shows a state in which the gas is discharged by a vent (not shown) by an arrow y1. In FIG. 7C, gas is discharged from all joints. However, it is not necessary to discharge gas from all joints.

As indicated by reference numeral S403 in FIG. 6 and as shown in FIG. 7D, when the raw material 31 is substantially filled in the mold 33, the injection molding is performed from the (narrow sense) injection step to the pressure increase (pressure increase) step. Migrate to That is, the pressure of the raw material 31 in the mold 33 is increased to a predetermined pressure (final pressure) by the pressure applied by the plunger 45. Thereafter, the final pressure is maintained (pressure holding step). The raw material 31 filled in the molding die 33 is solidified by receiving heat from the plunger 45 and depriving the molding die 33 of heat.

Thereafter, the mold 33 is opened by a mold clamping device (not shown). The molded body 35 remains in one of the plurality of split dies 41 and is pushed out from the split dies 41 by pins (not shown).

(Configuration of mold)
FIG. 8 is a cross-sectional view showing the mold 33. In FIG. 8, not only a so-called cross section that is hatched but also a mating surface of the split mold 41 that is located behind the cross section is shown. FIG. 9 is a plan view of the mold 33. All of these show the mold 33 in a closed state.

The molding die 33 is constituted by, for example, a mold. As shown in FIG. 8, the space formed in the closed mold 33 includes a cavity 47 that forms a portion to be the chip 5, and a runner for causing the raw material 31 to flow into the cavity 47 from the outside of the mold 33. 49 and sprue 51. The molding die 33 has a gate (gate portion) 53 that is an opening for connecting the runner 49 and the cavity 47.

The shape and dimensions of the cavity 47 are basically the same shape and dimensions as the molded body 35 that becomes the chip 5. That is, the mold 33 has surfaces corresponding to the pair of main surfaces 9, the side surfaces 11, the blade portions 13, and the like of the chip 5. In the present embodiment, since the blade portion 13 protrudes from the main surface 9, the molding die 33 has a recess 47 r that retreats from the surface corresponding to the main surface 9.

As can be understood from the description of the gate mark 30 described above, the gate 53 is located at a height between the upper surface and the lower surface of the mold 33 and is present at a portion surrounded by the outer peripheral surface. Specifically, the gate 53 opens at the mounting hole forming surface 33 a corresponding to the inner surface of the mounting hole 25 of the mold 33. More specifically, the gate 53 opens at a position corresponding to the insertion portion 29 of the mounting hole 25 (the tip side of the protruding portion 41p) on the mounting hole forming surface 33a. The gate 53 is configured as a so-called ring gate, for example, and is open over 360 ° around the z-axis.

Therefore, the raw material 31 supplied to the runner 49 is injected through the gate 53. Specifically, the raw material 31 flows from the center side of the cavity 47 to the outer peripheral side. In other words, it flows from the mounting hole 25 to the plurality of cutting blades 19.

The runner 49 is a disc-shaped flow path, for example, corresponding to the gate 53 being a ring gate as described above. The size of the runner 49 in the thickness direction (z-axis direction) may be different from that of the gate 53 or may be the same.

The sprue 51 communicates with the runner 49 and opens on the outer surface of the molding die 33. The sprue 51 extends, for example, in the thickness direction (z-axis direction), and is formed in a tapered shape so that the outer side of the mold 33 is reduced in diameter.

The molding die 33 is divided into, for example, the top, bottom, left and right with respect to the cavity 47, and has a total of four split dies 41. That is, the mold 33 includes a first main surface split mold 41A that constitutes one main surface 9 side of the chip 5, a second main surface split mold 41B that constitutes the other main surface 9 side of the chip 5, and a chip. 5 and two side surface split molds 41 </ b> C constituting the outer peripheral side. The sprue 51 described above is provided, for example, in the first main surface split mold 41A. The runner 49 is configured, for example, between the first main surface split mold 41A and the second main surface split mold 41B.

The first main surface split mold 41A and the side split mold 41C are divided, for example, along a ridge line 47a corresponding to the cutting edge 19 in the cavity 47, and a mating surface 47b that is a boundary (boundary portion) between them is It is connected to the ridgeline 47a.

The mating surface 47b of the first main surface split mold 41A or the second main surface split mold 41B and the side split mold 41C, for example, intersects the surface corresponding to the rake face 15 and the surface corresponding to the flank face 17. When the two virtual surfaces VS extended to the side (the ridge line 47a side corresponding to the cutting edge 19) are considered, they are located between the two virtual surfaces VS (excluding the position matching the virtual surface VS).

The two side surface split molds 41C are divided, for example, at the center of the short side in plan view, and the mating surfaces of both are connected to the center of the short side.

As described above, the cutting tool tip 5 according to the present embodiment is located between the pair of main surfaces 9 (upper surface and lower surface) and the pair of main surfaces 9 and connects the pair of main surfaces 9. A base material having four side surfaces 11 is provided, and a gate mark 30 is located at a height between a pair of main surfaces 9 in the base material and surrounded by the outer peripheral surface 12. Specifically, the cutting tool tip 5 according to the present embodiment has a cutting edge 14 and a hole (attachment hole 25) in the base material 6, and the gate mark 30 is located in the attachment hole 25. is doing.

Therefore, there is no possibility that the gate trace 30 interferes with the work material as in the case where the gate trace 30 is located on the side surface 11, for example. That is, the possibility that the gate mark 30 adversely affects the cutting performance is reduced. In addition, since the gate mark 30 is in a region where the possibility of adversely affecting the cutting performance is low (in the mounting hole 25), there are few design restrictions in the region. As a result, for example, the gate 53 can be provided at an appropriate position in consideration of the flow of the raw material 31.

Furthermore, when one of the pair of main surfaces 9 comes into contact with the holder 3 when the chip 5 is attached to the holder 3, the gate mark 30 is separated from the surface in contact with the holder 3. Therefore, it is possible to avoid the smoothness of the surface of the chip 5 that contacts the holder 3 from being deteriorated by the gate mark 30. Therefore, the chip 5 can be stably attached to the holder 3.

Further, in the present embodiment, the mounting hole 25 which is a fixing hole is a first portion (one receiving portion 27) located on the first opening (one opening 26) side of the mounting hole 25. ) And a second part (insertion portion 29) that is narrower than the first part and located deeper than the first part, and a gate mark 30 is provided in the second part. ing.

Therefore, for example, in fixing the chip 5 with the screw 7 inserted into the mounting hole 25, the screw head 7b that must be brought into contact with the chip 5 is brought into contact with the non-arranged region (receiving portion 27) of the gate mark 30; The male screw portion 7 a that does not necessarily need to contact the chip 5 can be located in the arrangement region (insertion portion 29) of the gate mark 30. As a result, since the screw 7 and the gate trace 30 are in a non-contact state, the possibility that the gate trace 30 adversely affects the fixing of the chip 5 is reduced, and the chip 5 is positioned with respect to the holder 3 with high accuracy. Can do.

In the present embodiment, the mounting hole 25 is a through hole. The mounting hole 25 has a third portion (the other receiving portion 27) located on the second opening (the other opening 26) side opposite to the first opening (the one opening 26). The second part (insertion part 29) is located between the first part (one receiving part 27) and the third part.

Therefore, for example, since the gate trace 30 is provided at a position away from the surface (both main surfaces 9) of the chip 5, the possibility that the gate trace 30 adversely affects the cutting performance is further reduced. In addition, the effect of separating the male screw portion 7a from the gate trace 30 described above is exhibited even when the chip 5 is fixed to the holder 3 in any of the upper and lower directions.

In this embodiment, the surface roughness of the gate mark 30 (insertion part 29) is larger than the area adjacent to the gate mark 30 (for example, the first part: the receiving part 27).

Therefore, for example, the insertion portion 29 has a larger surface area ratio with respect to the occupied area or the projected area than the receiving portion 27, and heat dissipation is improved. As a result, for example, heat accumulated in the base material 6 with cutting can be suitably dissipated. This effect is exhibited not only when the gate trace 30 (base material 6) is exposed, but also when the gate trace 30 is covered with the coating layer. For example, if the surface of the coating layer is rough due to the influence of the surface roughness of the gate trace 30, the surface area of the coating layer increases and heat dissipation is improved. Even if the surface of the coating layer is not rough, the contact area between the gate mark 30 and the coating layer increases due to the rough surface of the gate mark 30, so that heat can be easily transferred from the base material 6 to the coating layer. It becomes easy to dissipate the heat of the base material 6.

Further, in the present embodiment, the cutting edge portion 14 is provided at a position farthest from the gate mark 30 in the axial direction of the mounting hole 25.

Therefore, the possibility that the gate mark 30 adversely affects the cutting performance can be further reduced. Further, when focusing on the manufacturing process, the molding accuracy of the cutting edge portion 14 is improved. Specifically, for example, it is as follows. In the injection molding, as described with reference to FIG. 7D, the raw material 31 is solidified while applying a relatively high pressure to the raw material 31. As a result, when the raw material 31 is solidified and its volume is reduced and a gap is generated between the raw material 31 and the inner surface of the mold 33, the raw material 31 is further pushed in. At this time, the amount of deviation of the solidified raw material 31 with respect to the molding die 33 increases as the distance from the gate 53 increases. However, in this embodiment, since the cutting edge part 14 is located in the position away from the gate 53, a possibility that the shaping | molding precision of the cutting edge part 14 may fall by such deviation | shift is reduced.

In this embodiment, when viewed from the direction along the axial direction (z-axis direction) of the mounting hole 25, the gate mark 30 has an annular shape surrounding the axis of the mounting hole 25.

Therefore, for example, the effect of improving the heat dissipation described above is exhibited over the entire circumference of the mounting hole 25. For example, when attention is paid to the manufacturing process, since the raw material 31 flows from the gate 53 provided as a ring gate in all directions, the generation of the weld line caused by the joining of the raw material 31 is suppressed.

In the present embodiment, in the cross section (longitudinal cross section) including the axis of the mounting hole 25, the direction in which the gate mark 30 protrudes (y-axis direction) is the direction in which the cutting edge 19 in the cutting edge portion 14 protrudes ( It is inclined with respect to the z-axis direction).

Therefore, for example, the stress in the protruding direction is hardly transmitted between the cutting edge 19 and the gate mark 30. As a result, for example, the possibility that the chip 5 is deformed such that the gate mark 30 is pressed against the screw 7 or the like, or that unintended stress is transmitted from the gate mark 30 to the cutting blade 19 is reduced.

In the present embodiment, the cutting tool 1 includes the tip 5 as described above and the holder 3 to which the tip 5 is fixed. Further, the chip 5 is fixed to the holder 3 by a screw 7 inserted into the mounting hole 25.

Therefore, the hole (mounting hole 25) provided with the gate mark 30 can be used for mounting the chip 5. From another viewpoint, the mounting hole 25 for mounting the chip 5 can be used as a hole for arranging the gate mark 30, and it is not necessary to provide a hole for hiding the gate mark 30. As a result, for example, the chip 5 can be simplified.

In this embodiment, the screw 7 and the gate trace 30 are not in contact with each other. In another aspect, the screw 7 is engaged with the base material 6 outside the gate mark 30. Here, “outward” means a direction approaching the opening 26 in the mounting hole 25.

Therefore, as described above, the possibility that the gate trace 30 adversely affects the mounting of the chip 5 is reduced. Moreover, the possibility that the male screw portion 7a of the screw 7 is damaged by the gate mark 30 is reduced. As a result, for example, the possibility that the male screw portion 7a cannot be reused is reduced.

<Other embodiments>
In the first embodiment, the tip 5 that is generally a rectangular parallelepiped and forms an end mill is taken as an example. However, the position of the gate mark 30 of the first embodiment is applicable to other various cutting tool tips. Below, some are illustrated.

Second Embodiment
FIG. 10A is a perspective view showing a cutting tool tip 205 according to the second embodiment.

The chip 205 is a substantially triangular chip in plan view, and is used, for example, as a bite chip. The tip 205 has a pair of main surfaces 209 and three side surfaces 211, and three blade portions 213 (this embodiment) are formed at corners of one of the pair of main surfaces 209 and the three side surfaces 211. In the form, it is the same as the cutting edge portion). Three blade portions 213 may be formed at the corners of the other main surface 209 and the three side surfaces 211.

The blade part 213 includes, for example, a rake face 215 made of a land parallel to a central portion of the main surface 209, a flank face 217 formed by the side face 211, and a cutting edge 219 (and a corner 221) that intersect with these. ). Thus, the blade part 213 may be comprised by the corner | angular part of the main surface or side surface, or a surface parallel to these, without protruding with respect to a main surface or a side surface.

Further, the chip 205 has a mounting hole 225.

FIG. 10B is a cross-sectional view of a molding die 233 for forming a molded body to be the chip 205, and corresponds to the Xb-Xb line in FIG. FIG. 10C is a plan view showing a part of the molding die 233 (side split mold 241C).

In the molding die 233, a cavity 247 corresponding to the chip 205 and a runner 249 communicating with the cavity 247 are formed. The gate 253 connecting the cavity 247 and the runner 249 is, for example, in the insertion portion (a portion having a constant diameter in the penetration direction) of the mounting hole forming surface 233a that forms the inner surface of the mounting hole 225, as in the first embodiment. It is provided in a ring shape in the corresponding region.

The gate mark is located at the center of the chip 205 in the thickness direction or below the center, and the blade part 213 (cutting edge part) is provided at the position farthest from the gate mark in the axial direction of the mounting hole 225. Further, although different from the illustrated example, if receiving portions are provided at both ends of the mounting hole 225, the direction in which the gate mark protrudes in the longitudinal section is the direction in which the cutting edge 219 of the blade 213 protrudes (oblique 45 °). Inclined with respect to (upward).

At this time, the gate 253 may be separated from the main surface 209 where the blade portion 213 is not provided. In this case, for example, as described in the first embodiment, it is possible to avoid the smoothness of the surface of the chip 5 that contacts the holder 3 from being deteriorated by the gate mark.

Mold 233 may be appropriately divided. For example, the mold 233 is divided along the ridge line 247a (FIG. 10B) corresponding to the cutting edge 219, as in the first embodiment, and the first main surface split mold 241A and the second main surface split mold. 241B and three side surface split molds 241C.

<Third Embodiment>
FIG. 11A is a perspective view showing a cutting tool tip 305 according to the third embodiment.

The chip 305 is a substantially hexagonal chip in a plan view, and is used, for example, as a face milling chip. The chip 305 has a pair of main surfaces 309 and six side surfaces 311, and twelve blade portions 313 are formed at corners of the pair of main surfaces 309 and the six side surfaces 311. Yes.

The hexagon has a 120 ° rotationally symmetric shape, and three corners at 120 ° rotationally symmetric positions are smaller than the other three corners. Two cutting blades 319 connected by a corner 321 located at a relatively small corner are used simultaneously, and constitute a cutting blade portion 314.

The rake face 315 extends from the central side of the main surface 309 and extends so as to rise at the outer peripheral edge of the main surface 309, and the flank 317 continues from the central region in the thickness direction of the side surface 311 and The cutting edge 319 extends beyond the center side and is higher than the center side of the main surface 309.

Further, the chip 305 has a mounting hole 325.

FIG. 11B is a cross-sectional view of a molding die 333 for forming a molded body to be the chip 305, and corresponds to the line XIb-XIb in FIG. FIG. 11C is a plan view showing a part of the molding die 333 (side split mold 341C).

In the molding die 333, a cavity 347 corresponding to the chip 305 and a runner 349 communicating with the cavity 347 are formed. The gate 353 that connects the cavity 347 and the runner 349 is provided in a ring shape in a region corresponding to the insertion portion of the mounting hole forming surface 333a that forms the inner surface of the mounting hole 325, for example, as in the first embodiment. ing.

The gate mark is located at the center of the chip 305 in the thickness direction, and the blade part 313 (cutting edge part 314) is provided at a position farthest from the gate mark in the axial direction of the mounting hole 325. In the longitudinal section, the direction in which the gate mark protrudes is inclined with respect to the direction in which the cutting edge 319 of the blade portion 313 protrudes (oblique vertical direction).

Mold 333 may be divided as appropriate. For example, the molding die 333 is divided along the ridge line 347a (FIG. 11B) corresponding to the cutting edge 319, as in the first embodiment, and the first main surface dividing die 341A and the second main surface dividing die. 341B and three side split molds 341C are provided. The three side surface split molds 341C may be divided, for example, at positions corresponding to the corners 321 of the chip 305 as shown in the figure, or different from the figure, corresponding to the center of each side of the chip 305. It may be divided at a position.

<Fourth embodiment>
FIG. 12A is a perspective view showing a cutting tool tip 405 according to the fourth embodiment.

In the first to third embodiments described above, the cutting edge is located at the corner between the main surface and the outer peripheral surface, whereas in the tip 405, the cutting edge is located on the outer peripheral surface. Also in such an aspect, the above-described gate trace position may be applied. Specifically, it is as follows.

The chip 405 is a roughly triangular chip in plan view, and is used, for example, as a chip for a grooving tool. The tip 405 generally has a pair of main surfaces 409 and three side surfaces 411 (outer peripheral surface 412), and three blade portions 413 (cut in this embodiment) at corners of the three side surfaces 411. The same as the blade part).

The blade portion 413 includes, for example, a concave rake face 415 positioned on the corner side of one side face 411, and a relief face 417 that is a part formed by chamfering another side face 411 continuous to the rake face 415, It has a cutting edge 419 located at the intersection of the rake face 415 and the flank face 417. The cutting edge 419 extends in the thickness direction of the tip 405.

Further, the chip 405 has a mounting hole 425.

FIG. 12B is a cross-sectional view of a molding die 433 for forming a molded body to be the chip 405, and corresponds to the XIIb-XIIb line in FIG. FIG. 12C is a plan view showing a part of the molding die 433 (side split mold 441C).

In the mold 433, a cavity 447 corresponding to the chip 405 and a runner 449 communicating with the cavity 447 are formed. The gate 453 that connects the cavity 447 and the runner 449 is provided in a ring shape in a region corresponding to the insertion portion of the mounting hole forming surface 433a that forms the inner surface of the mounting hole 425, for example, as in the first embodiment. ing.

However, unlike the other embodiments, the blade portion 413 (cutting blade portion) is not provided at the position farthest from the gate mark in the axial direction of the mounting hole 425. In the longitudinal section, the direction in which the gate mark protrudes is not inclined with respect to the direction in which the cutting edge 419 of the blade portion 413 protrudes (the left-right direction in this embodiment).

As in the second embodiment, the gate 453 may be provided at an appropriate position in the insertion portion that extends from the receiving portion to the main surface on the opposite side of the receiving portion. In the illustrated example, like the second embodiment, the cavity 447 is provided on the center side in the thickness direction.

Mold 433 may be appropriately divided. For example, the mold 433 is divided along the ridge line 447a (FIG. 12C) corresponding to the cutting edge 419, as in the other embodiments, and the first main surface split mold 441A and the second main surface split mold. 441B and three side surface split molds 441C. However, unlike the other embodiments, the surface constituting the ridge line 447a appears in a cross-sectional view along the main surface 409.

<Fifth Embodiment>
FIG. 13A is a cross-sectional view showing a part of the tip of an insert-type cutting tool 501 according to the fifth embodiment.

The cutting tool 501 is different from the cutting tool 1 of the first embodiment in that the tip 505 is attached to the holder 503 by so-called clamping. Specifically, it is as follows.

The cutting tool 501 has, for example, a clamp member 504 for clamping the tip 505 and a screw 507 for fastening the clamp member 504 to the holder 503 in addition to the holder 503 and the tip 505.

The clamp member 504 has, for example, a contact portion 504a into which the tip is inserted into the mounting recess 525 (hole) of the chip 505. The contact portion 504a can contact the inner peripheral surface of the mounting recess 525 to position the chip 505 in the left-right direction on the paper surface, and can contact the upper surface of the chip 505 to position the chip 505.

Further, the clamp member 504 has a sliding portion 504b that is slidable with respect to the inclined surface 503a formed on the holder 503. The inclined surface 503a is located on the opposite side of the chip 505 with the female screw portion 503b formed on the holder 503 interposed therebetween, and faces the opposite side of the chip 505, and further away from the chip 505 toward the lower side. Inclined.

When the chip 505 is fixed to the holder 503, the screw 507 is inserted into the clamp member 504 from above, and the male screw portion 507a of the screw 507 is screwed into the female screw portion 503b of the holder 503. The clamp member 504 receives a downward force from the screw head 507b of the screw 507. As a result, as indicated by an arrow y5, a downward force is applied to the upper surface of the chip 505 by the contact portion 504a. Further, as the sliding portion 504b slides on the inclined surface 503a, the clamp member 504 tries to move in the direction indicated by the arrow y6. As a result, a force that draws the tip 505 toward the clamp member 504 is applied to the inner peripheral surface of the mounting recess 525 by the contact portion 504a. As a result, the chip 505 is positioned by being pressed against the bottom surface and the inner peripheral surface of the recess 503r of the holder 503.

In such a method of fixing the chip 505, the hole for fixing the chip 505 (attachment recess 525) does not need to be a through hole, and the hole is also a recess in this embodiment. However, even in such a fixing method, the hole portion of the chip 505 may be a through hole.

FIG. 13B is a cross-sectional view of a molding die 533 for forming a molded body that becomes the chip 505.

In the molding die 533, a cavity 547 corresponding to the chip 505 and a sprue 551 communicating with the cavity 547 are formed. In addition, in this embodiment, although it is set as the direct gate where a runner is not provided, a runner may be provided.

The gate 553 that connects the cavity 447 and the sprue 551 is provided on the mounting recess forming surface 533a that forms the inner surface of the mounting recess 525, for example, as in the other embodiments. However, the mounting recess forming surface 533a includes a surface that forms the bottom surface of the mounting recess 525, corresponding to the mounting recess 525 being a recess, and the gate 553 is open to the surface that forms the bottom surface. Yes.

Note that the mold 533 may be appropriately divided. FIG. 13B illustrates a case where the image is divided into two at the center in the vertical direction, and the dividing surface is positioned on the side surface of the chip 505. However, similarly to the other embodiments, the division may be performed along the ridgeline constituting the cutting edge.

FIG. 13C is a cross-sectional view showing a molded body 535 formed by the mold 533 of FIG. 13B. The molded body 535 has a portion that becomes the chip 505 and an unnecessary portion, as in the other embodiments. However, in the molded body 535, the unnecessary portion protrudes from the bottom surface of the recess that becomes the mounting recess 525. Then, unnecessary parts in the molded body 535 are removed, the molded body 535 is baked, and the like, and the chip 505 is formed.

FIG. 13D is a cross-sectional view of the chip 505 formed by removing unnecessary portions.

As understood from the above description, in the chip 505, the gate trace 530 is formed on a part (for example, the center) of the bottom surface of the mounting recess 525. In addition, as for the chip | tip 505, the blade part 513 (cut blade part) may be comprised by the ridgeline of the upper surface (main surface 509) and the side surface 511 similarly to 2nd Embodiment (FIG. 10 (a)), for example. .

In the above embodiment, the mounting

holes

25, 225, 325 and 425 and the mounting recess 525 are examples of holes. The pair of receiving portions 27 is an example of a first part and a third part. The insertion part 29 is an example of a second part.

The present invention is not limited to the above embodiment, and may be implemented in various modes.

For example, the cutting tool is not limited to the insert type, and may be one in which the chip is brazed. Even in the brazed tip, if the gate mark is located in the hole, the possibility that the gate mark adversely affects the cutting performance is reduced. Moreover, when the cutting tool is of an insert type, the chip attaching / detaching method may be a combination of a screw and a clamp.

The hole portion of the chip may have no taper portion (screw receiving portion) as exemplified in the fifth embodiment. The same applies to the case where fixing is performed with screws (in the case of through holes from another viewpoint).

The gate mark may come into contact with a screw or a clamp member inserted into the hole. Even in this case, for example, the possibility that the gate trace interferes with the work material is reduced.

DESCRIPTION OF SYMBOLS 1 ... Cutting tool, 5 ... Chip for cutting tool, 6 ... Base material, 9 ... Main surface, 11 ... Side surface, 12 ... Outer peripheral surface, 14 ... Cutting blade part, 19 ... Cutting blade, 25 ... Mounting hole (hole part) 30 ... Gate mark, 31 raw material, 33 ... Mold, 33a ... Mounting hole forming surface, 35 ... Molded body, 39 ... Sintered body, 41 (41A-41C) ... Split mold, 47 ... Cavity, 47a ... Ridge line, 47b ... mating surface (boundary part), 47r ... concave part, 53 ... gate.

Claims

A base material having an upper surface, a lower surface, and an outer peripheral surface located between the upper surface and the lower surface, the height between the upper surface and the lower surface of the base material, Cutting tool insert with gate marks located in the enclosed area.
2. The cutting tool tip according to claim 1, wherein the base material has a hole, and the gate mark is located in the hole.
The hole includes a first part located on the first opening side of the hole, and a second part that is narrower than the first part and located deeper than the first part. The cutting tool tip according to claim 2, wherein the gate mark is provided at the second portion.
The hole is a through hole,
The hole has a third part located on the second opening side opposite to the first opening, and the second part is between the first part and the third part. The cutting tool tip according to claim 3, which is located in
The base material includes a cutting edge portion, and the cutting edge portion is provided at a position furthest away from the gate mark in the axial direction of the hole portion. Cutting tool tips as described in 1.
The cutting tool tip according to any one of claims 2 to 5, wherein when viewed from a direction along the axial direction of the hole portion, the gate mark has an annular shape surrounding the shaft of the hole portion.
The base material includes a cutting edge, and in a cross section including the axis of the hole, the direction in which the gate mark protrudes is inclined with respect to the direction in which the cutting edge in the cutting edge protrudes. The cutting tool tip according to any one of claims 2 to 6.
The tip for a cutting tool according to any one of claims 1 to 7, wherein a surface roughness of the gate trace is larger than a surface roughness of a region adjacent to the gate trace.
A cutting tool tip according to any one of claims 1 to 8,
A cutting tool comprising a holder to which the cutting tool tip is fixed.
The base material in the cutting tool tip comprises a hole,
The cutting tool according to claim 9, wherein the cutting tool tip is fixed to the holder by a screw inserted into the hole.
The cutting tool according to claim 10, wherein the screw and the gate mark are in a non-contact state.
The cutting tool according to claim 10 or 11, wherein the screw is engaged with the base material outside the gate mark.
A method for manufacturing a cutting tool tip,
Injecting the raw material into the mold through the gate part;
Cutting the gate portion to obtain a molded body having an upper surface, a lower surface, and an outer peripheral surface located between the upper surface and the lower surface,
The said gate part is located in the height between the said upper surface and the said lower surface of the said molded object, The manufacturing method of the chip | tip for cutting tools which exists in the site | part enclosed by the said outer peripheral surface.