JP4198823B2 - Cutting tool manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique capable of manufacturing a cutting tool at a low cost.
[0002]
[Prior art]
A cutting tool structure in which a cutting tip having a higher hardness is attached to the tip of the tool steel and cutting is performed with this cutting tip is widely adopted. For example, the manufacturing method of the cutting tip is (1) -63717 gazette "Twist drill" and (2) Japanese Utility Model Laid-Open No. 3-117520 gazette "Drill".
[0003]
In the above (1), as shown in FIG. 5, a wedge-shaped ultrahigh-pressure sintered body chip 10 (reference numeral is diverted from the publication) is integrated with a cylindrical body portion 9. The starting material 8 of the cutting blade 4 is used. After such a starting material 8 is bonded to the tool body by a technique such as brazing, the shape of the blade is adjusted.
[0004]
The above (2) is characterized in that a pentagonal chip material indicated by an imaginary line is cut out from a disk surrounded by a ring of hard sintered body 2 with cemented carbide 3 as shown in FIG. It is a thing.
[0005]
[Problems to be solved by the invention]
In the above (1), it is difficult to manufacture the starting material 8, the starting material 8 becomes expensive, the cost of the cutting tip increases, and the cutting tool becomes expensive.
The above (2) is the cost of cutting tips because only one or several pentagonal tip materials can be cut out from a disc of cemented carbide 3 surrounded by a ring of hard sintered body 2 and the yield is poor. In addition, the effect of lowering the cost of the cutting tool cannot be expected so much.
Then, the objective of this invention is providing the method which can manufacture an inexpensive cutting tool.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the present invention, there is provided a method for manufacturing a cutting tool comprising a shank and a tip attached to the shank. The second layer is a high hardness sintered body of CBN or diamond. A preparatory step of preparing a three-layer laminate sandwiched between a first layer and a third layer made of a tool material such as cemented carbide;
A first cutting step of cutting a columnar material having a rectangular cross section by cutting in order of the first layer, the second layer, and the third layer substantially perpendicularly to the upper surface of the first layer;
A chip semi-finished product including the second layer in the center by cutting the columnar material at a cutting surface substantially orthogonal to the cutting surface in the first cutting step and substantially perpendicular to the upper surface of the first layer. A second cutting step of cutting,
A joining step of joining this semi-finished chip product to a separately prepared shank;
And a finishing process to obtain a chip by forming a rake face, a cutting edge and a flank face on the chip semi-finished product,
In the second cutting step, a cutting surface that is substantially perpendicular to the cutting surface and substantially perpendicular to the upper surface of the first layer is composed of two cutting surfaces, and has a shape in plan view , The angle at which the two cut surfaces intersect is the same angle as the tip angle of the cutting tip, and such a cut surface in a plan view in plan view is configured in the same shape at the tip and rear end of the semi-finished chip product. ,
The angle of the tip of the joint portion of the separately prepared shank is the same as the tip angle of the cutting tip.
[0007]
The three-layer laminate is cut (sliced into stripes), and the obtained columnar material is further cut to cut a large number of chip semi-finished products, and these chip semi-finished products are finished into chips.
Since the yield is extremely good, the manufacturing cost of the chip can be greatly reduced, and thus the manufacturing cost of the cutting tool can be reduced.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view of a three-layer structure adopted in the present invention. The three-layer structure 10 is a high-hardness sintered body of CBN or diamond as a second layer 11, and this second layer 11 is made of a cemented carbide. A laminated body sandwiched between a first layer 12 and a third layer 13 made of a tool material such as For example, the thickness of the second layer 11 is about 1 mm, the thickness of the first layer 12 and the third layer 13 is about 5 mm, and the thickness of the three-layer structure 10 is about 11 mm.
[0009]
Note that CBN is an abbreviation of cubic boron nitride, that is, cubic boron nitride, and is an artificial abrasive widely used with diamond. CBN is suitable for cutting ferrous workpieces and diamond is suitable for cutting non-ferrous workpieces.
[0010]
An example of a method for producing the three-layer structure 10 will be described. First, 4 to 16 μm diamond grains or CBN grains are sintered while being pressurized isotropically by HIP (hot isostatic pressing). The second layer 11 is manufactured, and the WC powder is stacked on the upper and lower sides of the second layer 11 and sintered while being pressed with HIP to obtain the three-layer structure 10.
HIP can be replaced with HP (hot press) or CIP (cold isostatic press), and the manufacturing method is not particularly limited as long as it is a well-known sintering method.
[0011]
FIG. 2 is a plan view of the three-layer structure adopted in the present invention (a figure corresponding to the plan view of FIG. 1), and is along an imaginary line 15 (... indicates a plurality, the same applies hereinafter). In addition, by cutting the three-layer structure 10 perpendicularly or substantially perpendicularly to the upper surface of the first layer 12, a large number of columnar materials 20 are cut out. This is sometimes called a deadline.
As is apparent from the figure, the columnar materials 20 can be cut out with a very high yield (for example, a yield of 90%).
[0012]
FIG. 3 is a perspective view of the columnar material according to the present invention. The columnar material 20 is a long material having an a × a square cross section, and is a laminate of the first layer 12, the second layer 11, and the third layer 13. is there. A plurality of chip semi-finished products 30... Are obtained by cutting the columnar material 20 at a cutting surface 22, which is substantially orthogonal to the cutting surface 21 cut in FIG.・ ・
[0013]
FIG. 4 is a perspective view of a chip semi-finished product according to the present invention. The chip semi-finished product 30 is a piece in which the front surface 31 has a convex surface and the back surface 32 has a concave surface. You can do it.
[0014]
FIG. 5 is a view taken in the direction of the arrow 5 in FIG. 4, and the chip semi-finished product 30 is cut from the drawing table to the back by electric discharge machining along a cut line 33 indicated by an imaginary line. The cut line 33 is characterized in that it substantially leaves the second layer 11 and significantly cuts the first layer 12 and the third layer 13. The chip 40 is cut and shaped.
[0015]
Hereinafter, a cutting tool having the tip 40 as a main element will be described in order by using a drill, a thread cutting tool, an end mill, and a tap as specific examples.
FIG. 6 is a schematic diagram when the tip according to the present invention is attached to the shank. A drill 50 as a cutting tool is prepared by joining the tip 40 to the tip of a drill-shaped shank 51 with a filter 52 and adjusting the blade. Is.
[0016]
FIG. 7 is a view taken in the direction of arrow 7 in FIG. 6 and shows the tip shape of the prepared drill 50 in which the chisel edge 53, grooves 54 and 54, rake surfaces 55 and 55, cutting edges 56 and 56, and flank surfaces 57 and 57 are formed. .
[0017]
As is clear from the above description, the method for manufacturing a cutting tool of the present invention described using a drill as an example has a high hardness sintered body of CBN or diamond as the second layer 11, and the second layer 11 is made of cemented carbide or the like. A preparation step of preparing the three-layer laminate 10 sandwiched between the first layer 12 and the third layer 13 made of the above-mentioned tool material, and the first layer 12, the second layer 11, substantially perpendicular to the upper surface of the first layer 12, In the first cutting step of cutting the columnar material 20 having a rectangular cross section by cutting the third layer 13 in this order, and the cutting surface 22 orthogonal to or substantially orthogonal to the cutting surface 21 in the first cutting step, the columnar material 20 is formed. A second cutting step of cutting the chip semi-finished product 30 including the second layer 11 in the center by cutting the chip, a joining step of joining the chip semi-finished product 30 to a separately prepared shank 51, and a chip semi-finished product Finished product 30 There surface 55, cutting edge 56, to form a flank 57, characterized in that to produce a drill 50 as a cutting tool from a finishing process to obtain a chip 40.
[0018]
By adopting this manufacturing method, as apparent from FIGS. 2 and 3, the product yield becomes extremely high, and a large number of chips can be manufactured at low cost.
[0019]
The manufacturing method of the thread cutting tool will be described with reference to FIGS.
8 (a) and 8 (b) are diagrams for explaining the manufacture of the threading tool according to the present invention.
4A is further cut along the cut lines 34 and 34 shown by broken lines in the chip semi-finished product 30 of FIG.
(B) shows the obtained secondary chip semi-finished product 35.
[0020]
FIG. 9 is a view taken in the direction of arrow 9 in FIG. 8B. The secondary chip semi-finished product 35 is cut from the front to the back of the drawing by electric discharge machining along a cut line 36 indicated by an imaginary line. The cut line 36 is characterized in that it almost leaves the second layer 11 and significantly cuts the first layer 12 and the third layer 13. The chip 40 is cut and shaped. The chip 40 is cut and molded.
FIG. 10 is a plan view of the threading tool according to the present invention. The threading tool 60 joins the tip 40 of the present invention to the tip of the shank 61 with a filter 62 to form a bottom blade 63 and threading blades 64 and 64. It is a thing.
[0021]
Next, an end mill manufacturing method will be described with reference to FIGS.
FIG. 11 is a perspective view of a columnar material according to a reference example of the present invention. The columnar material 20 is a long material having an a × a square cross section, and the first layer 12, the second layer 11, and the third layer 13. It is a laminate. By cutting the columnar material 20 at the cutting planes 23 orthogonal to the cutting plane 21 cut in FIG. 2, die-shaped chip semi-finished products 30 are obtained.
FIG. 12 is a view taken in the direction of arrow 12 in FIG. 11, and the chip semi-finished product 30 is cut from the drawing table to the back by electric discharge machining along a cut line 37 indicated by an imaginary line. The cut line 37 is characterized in that the second layer 11 is almost left and the first layer 12 and the third layer 13 are largely cut. The chip 40 is cut and shaped.
[0022]
13 is a front view of an end mill according to a reference example of the present invention, and shows an end mill 70 obtained by joining the tip 40 obtained by cutting in FIG. The end mill 70 is a cutting tool that cuts the cutting symmetry object 74 by sending it as indicated by the white arrow while rotating.
FIG. 14 is a view taken in the direction of arrow 14 in FIG. 13 and shows the tip shape of the trimmed end mill 70 in which rake faces 75, 75, cutting edges 76, 76 and flank faces 77, 77 are formed.
[0023]
Next, a tap manufacturing method will be described with reference to FIGS.
FIG. 15 is a perspective view of a columnar material according to a reference example of the present invention. The columnar material 20 is a long material having an a × a square cross section, and the first layer 12, the second layer 11, and the third layer 13. It is a laminate. By cutting the columnar material 20 at the cutting planes 23 orthogonal to the cutting plane 21 cut in FIG. 2, die-shaped chip semi-finished products 30 are obtained.
FIG. 16 is a perspective view of a chip semi-finished product according to a reference example of the present invention, and sawtooth portions 81 and 81 are formed on the sides of the chip semi-finished product 30 obtained in FIG. Item 35 is obtained.
FIG. 17 is a view taken in the direction of arrow 17 in FIG. 16, and the secondary chip semi-finished product 35 is cut from the drawing surface to the back by electric discharge machining along a cut line 38 indicated by an imaginary line. The cut line 38 is characterized in that the second layer 11 is almost left and the first layer 12 and the third layer 13 are greatly cut. The chip 40 is cut and shaped.
[0024]
FIG. 18 is a front view of a tap according to a reference example of the present invention, and shows a tap 80 obtained by joining the chip 40 obtained in FIG. 17 to the shank 82 with a filter 83.
FIG. 19 is a view taken in the direction of arrow 19 in FIG. 18 and shows the tip shape of the trimmed tap 80 on which the rake surfaces 85 and 85, the cutting edges 86 and 86, and the flank surfaces 87 and 87 are formed.
[0025]
In addition, the cutting tool manufactured with the manufacturing method of Claim 1 says cutting tools, such as a milling tool and a cutting tool other than the drill demonstrated in the Example, a thread cutting tool, an end mill, and a tap, and the kind is exceptionally limited. It is not a thing.
[0026]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
According to the first aspect, the three-layer laminate is cut, and the obtained columnar material is further cut to cut a large number of chip semi-finished products and finish these chip semi-finished products into chips. Since the yield is extremely good, the manufacturing cost of the chip can be greatly reduced, and thus the manufacturing cost of the cutting tool can be reduced.
[Brief description of the drawings]
1 is a cross-sectional view of a three-layer structure employed in the present invention. FIG. 2 is a plan view of a three-layer structure employed in the present invention. FIG. 3 is a perspective view of a columnar material according to the present invention. FIG. 5 is a perspective view of a semi-finished chip according to the invention. FIG. 5 is a view taken along the arrow 5 in FIG. 4. FIG. 6 is a schematic diagram when the chip according to the present invention is attached to the shank. [FIG. 9] View of arrow 9 in FIG. 8 (b) [FIG. 10] Plan view of the thread cutting tool according to the present invention [FIG. 11] Columnar shape according to a reference example of the present invention perspective view of the material reference example of FIG. 12 is a front view of the end mill according to a reference example 12 arrow diagram 13 present invention of FIG. 11 and FIG. 14 14 arrow view of FIG. 13 and FIG. 15 the present invention FIG. 16 is a perspective view of a semi-finished chip product according to a reference example of the present invention . FIG. 17 is a view taken along arrow 17 in FIG. 18 is a front view of a tap according to a reference example of the present invention. FIG. 19 is a view taken along arrow 19 in FIG.
DESCRIPTION OF SYMBOLS 10 ... 3 layer structure, 11 ... 2nd layer, 12 ... 1st layer, 13 ... 3rd layer, 20 ... Columnar material, 21 ... Cut surface in the 1st cutting process, 22 ... Cutting substantially orthogonal to the cutting surface 21 Surface, 23 ... Cutting surface orthogonal to cutting surface 21, 30, 35 ... Chip semi-finished product, 40 ... Chip, 50 ... Cutting tool (drill), 55, 75, 85 ... Rake face, 56, 76, 86 ... Cutting Blades 57, 77, 87 ... flank, 60 ... cutting tool (thread cutting tool), 63 ... bottom blade, 64 ... thread cutting blade, 70 ... cutting tool (end mill), 80 ... cutting tool (tap).

Claims (1)

In a manufacturing method of a cutting tool comprising a shank and a tip attached to the shank,
A preparation step of preparing a three-layer laminate in which a high-hardness sintered body of CBN or diamond is used as a second layer and the second layer is sandwiched between a first layer and a third layer made of a tool material such as cemented carbide,
A first cutting step of cutting a columnar material having a rectangular cross section by cutting in order of the first layer, the second layer, and the third layer substantially perpendicularly to the upper surface of the first layer;
A chip semi-finished product including the second layer in the center by cutting the columnar material at a cutting surface substantially orthogonal to the cutting surface in the first cutting step and substantially perpendicular to the upper surface of the first layer. A second cutting step of cutting,
A joining step of joining this semi-finished chip product to a separately prepared shank;
And a finishing process to obtain a chip by forming a rake face, a cutting edge and a flank face on the chip semi-finished product,
In the second cutting step, a cutting surface that is substantially perpendicular to the cutting surface and substantially perpendicular to the upper surface of the first layer is composed of two cutting surfaces, and has a shape in plan view , The angle at which the two cut surfaces intersect is the same angle as the tip angle of the cutting tip, and such a cut surface in a plan view in plan view is configured in the same shape at the tip and rear end of the semi-finished chip product. ,
The method of manufacturing a cutting tool, wherein the angle of the tip of the joint portion of the separately prepared shank is the same as the tip angle of the cutting tip.

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