JP4464117B2 - Cutting tool manufacturing method - Google Patents

Description

The present invention relates to a method of manufacturing a cutting tool such as a milling cutter or a hob cutter used for metal machining.

Conventionally, as this type of cutting tool, a lot of Muku-shaped blades and bodies made from the same material are used, and the material is high-speed steel (both tough and rigid) ( Heiss) is currently the best. In addition to the muku shape, there is also known a blade type or assembly type in which a blade constituting a blade portion is mechanically attached to the body (for example, see Non-Patent Document 1).
"JIS Handbook 2003 Tool" Japanese Standards Association (Pages 88-125, 151-200)

  However, the Muku-shaped cutting tool has a problem that a large amount of swarf is generated from the material to the product, and it is necessary to process it as scrap, which increases the product price accordingly. In particular, when high-speed steel is used as the material, it is necessary to manufacture the high-speed steel up to the part other than the blade, and this problem is caused because the high-speed steel is very expensive compared to general alloy steel. It is remarkable.

  On the other hand, such a problem can be solved by using a cutting tool of an insert type or an assembly type, but since the rigidity of the blade or the blade part is lower than that of the Muku type, the disadvantage is that the cutting accuracy is also reduced. There is.

The present invention has been made in view of the above points, and the object of the present invention is to provide a manufacturing method of a cutting tool that can effectively reduce resources and improve cutting accuracy by effectively using resources. To do.

  In order to solve the above-mentioned problems, the invention according to claim 1 is a method of manufacturing a cutting tool having a plurality of blade portions, a step of preparing blades having a predetermined shape constituting each of the blade portions, and the blade as a mold. After being inserted into the mold, a melted scrap of the same material as the blade is poured into the mold to cast a body integral with the blade, and after the body is cast, the blade is cut to form the blade portion It is set as the structure provided with.

  In this configuration, in the cutting process, only a blade having a predetermined shape is cut and the blade portion is formed, so that chips can be reduced compared to the Muku type, and the product price is reduced accordingly. be able to. Further, since scrap of the same material as the blade is used as a melt in the casting process of the body, resources can be reused, and the product price can be reduced also in this respect. Furthermore, since the blade and the body are integrated by casting, the rigidity of the blade or the blade portion can be ensured to the same extent as that of the mug-shaped one. In addition, since the scrap of the same material as the blade is used as a melt in the casting of the body and no difference in thermal expansion occurs between them, the integration by casting can be made stronger.

  According to a second aspect of the present invention, in the method for manufacturing a cutting tool according to the first aspect, both the blade and the scrap are made of high speed steel. In this configuration, since the blade constituting the blade portion is made of high-speed steel, both the toughness and rigidity of the blade portion can be increased, and the product price can be reduced by reusing expensive high-speed steel scrap. It is possible to further reduce the cost.

  According to a third aspect of the present invention, in the method for manufacturing a cutting tool according to the first or second aspect, the blade has a corner portion at a position embedded in the body in a casting process. In this configuration, since a part of the corner of the blade is unwound and integrated with the body in the casting process, the rigidity of the blade or blade can be further increased.

As described above, according to the method for manufacturing a cutting tool in the present invention, it is possible to reduce the amount of chips as compared with the conventional muku type, and the chips and scrap are melted and reused as materials. Therefore, resources can be reused and product prices can be reduced. In addition, since the rigidity of the blade portion can be ensured to the same extent as that of the Muku type, the cutting accuracy can be increased and the effect is excellent in practicality.

  In particular, in the invention according to claim 2, since the blade constituting the blade portion is made of high speed steel, both the toughness and rigidity of the blade portion can be increased, and the scrap of expensive high speed steel is reused. This makes it possible to further reduce the product price.

  Further, in the invention according to claim 3, since a part of the corner portion of the blade is unraveled and integrated with the body in the casting process of the body, the rigidity of the blade portion can be further increased and the cutting accuracy is further improved. be able to.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments that are the best mode for carrying out the present invention will be described below with reference to the drawings.

(First embodiment)
1 and 2 show a spiral bevel gear cutter 1 as a cutting tool according to a first embodiment of the present invention. The spiral bevel gear cutter 1 is attached to a machine main shaft such as a milling machine and has a ring shape on the front side. Cutting of gears, joints, and the like is performed by the plurality of arranged blade portions 2, 2,.

  The spiral bevel gear cutter 1 includes a ring-shaped blade 3 made of high-speed steel (high-speed steel) composed of a plurality of blade portions 2, 2,... And a high-speed steel made of the same material as the blade 3. It consists of a disk-shaped body 4 cast integrally with the blade 3 using scrap. The blade 3 is cut after the body 4 is cast to form a plurality of blade portions 2, 2,..., And each blade portion 2 is rotated in the rotational direction of the spiral bevel gear cutter 1 (as viewed from the front side). Counterclockwise) A cutting edge 5 is provided at the front end. A center hole 7 is provided at the center of the body 4 so as to be concentric with the axis on the machine spindle side. Around the center hole 7, four drive holes 8 for inserting mounting bolts are provided. , 8,... Are provided at equal intervals in the circumferential direction.

  Next, a method for manufacturing the spiral bevel gear cutter 1 will be described with reference to FIGS. 3 to 7 in addition to FIGS. First, as shown in FIGS. 3 and 4, a ring-shaped blade 3 made of high-speed steel for forming a plurality of blade portions 2, 2,... The blade 3 includes a ring-shaped constricted portion 11 whose thickness is gradually reduced on one end side (the lower end side in the figure), and a pair of ring-shaped portions each sharpened outward and inward at a position near the end of the constricted portion 11. .. Are provided at predetermined intervals in the circumferential direction at the inward position of the constricted portion 11. The small holes 13, 13,... It has been. The high-speed steel is mainly composed of iron, and is added with rare metals such as cobalt, tungsten, and molybdenum in order to increase hardness as a cutting tool, high-temperature machinability, and hardenability.

  Subsequently, as shown in FIG. 5, the blade 3 is placed in the middle mold 16 of the three-stage mold 18 in which the upper mold 15, the middle mold 16 and the lower mold 17 are stacked, and the constricted portion 11 and the corner portions 12 a and 12 b. Is inserted upward and exposed to the space of the middle mold 16. Then, after the mold 18 is clamped, the high-speed steel scrap, which is the same material as the blade 3, is heated and melted and injected into the mold 18 from the inlet 19 of the upper mold 15. The integral body 4 is cast. At this time, part of the corners 12a and 12b of the blade 3 is melted by the heat of the melt, and the melt flows into the small holes 13, so that the casting integration with the body 4 is firmly performed. After the mold 18 is opened, unnecessary portions are cut out from the body 4 to form a disk-shaped body 4 that is integral with the blade 3 and has the center hole 7 at the center as shown in FIGS. The

  Thereafter, drive holes 8 are provided around the center hole 7 of the body 4 by drilling. Further, the blade 3 is cut to form a plurality of blade portions 2, 2,. Thus, the spiral bevel gear cutter 1 as shown in FIGS. 1 and 2 is manufactured.

  Therefore, according to such a manufacturing method of the spiral bevel gear cutter 1, since only the blade portion 2 of the spiral bevel gear cutter 1 is formed by cutting the ring-shaped blade 3, the disc-shaped material is used. Chips can be reduced as compared with the Muku type that cuts out both the blade part 2 and the body 4, and the product price can be reduced accordingly. In addition, when the body 4 occupying most of the front fly cutter 1 is cast, scraps of the same material as the blade 3 are melted and used, so that resources can be reused. Can be further reduced. In particular, in this embodiment, since both the blade 3 and the body 4 are made of expensive high-speed steel, it is possible to further reduce the product price by reducing chips and reusing scrap.

  In addition, since the blade 3 and the body 4 are integrated by casting, the rigidity of the blade 3 or the blade portion 2 can be ensured to the same extent as that of the mug-shaped one, and the cutting accuracy is improved. it can. Further, in the casting of the body 4, high-speed steel, which is a scrap of the same material as the blade 3, is used as a melted material so that there is no difference in thermal expansion between them. Therefore, the cutting accuracy can be further improved. In particular, in this embodiment, since the casting integration of the blade 3 and the body 4 is firmly performed by unraveling part of the corner portions 12a and 12b of the blade 3, the rigidity of the blade portion 2 is improved and the cutting accuracy is improved. Further improvement can be achieved.

  In the above-described embodiment, when the body 4 is cast, the three-stage mold 18 in which the upper mold 15, the middle mold 16, and the lower mold 17 are stacked is used so that impurities in the melt are accumulated in the space of the lower mold 17. The quality of the body 4 is improved, but the present invention may use a normal mold made up of an upper mold and a lower mold when the purity of scrap used as a melt is high. Of course.

(Second Embodiment)
8 and 9 show a spiral bevel gear cutter 21 as a cutting tool according to a second embodiment of the present invention. Like the spiral bevel gear cutter 1 according to the first embodiment, the spiral bevel gear cutter 21 has a plurality of blade portions 22, 22,... Arranged in a ring shape on the front side. 22 is comprised by the braid | blade 23 which consists of a respectively different high speed steel.

  The spiral bevel gear cutter 21 has a disk-like body 24 that is integrally cast with the blade 23 using high-speed steel scrap made of the same material as the blade 23. Is provided with a central hole 27, and around the central hole 27, four drive holes 28, 28,... Are provided at equal intervals in the circumferential direction.

  Next, a manufacturing method of the spiral bevel gear cutter 21 will be described with reference to FIGS. 10 to 12 in addition to FIGS. First, as shown in FIG. 10, a plurality of substantially square columnar blades 23 made of high-speed steel for constituting one blade portion 22 are prepared. The blade 23 has a constricted portion 31 in which the thickness between a pair of two opposing sides of the four sides gradually decreases on one end side (the lower end side in FIG. 10B), and a position closer to the end of the constricted portion 31. Each of them has a pair of corners 32 and 32 that are pointed downward in the lateral direction, and a small hole 33 that penetrates in the constricting direction of the constricted portion 31 is provided at an inward position of the constricted portion 11.

  Subsequently, as in the case of the first embodiment, the plurality of blades 23, 23 are placed in the middle mold 16 of the three-tiered mold 18 as shown in FIG. ,... Are inserted with the constricted portion 31 and the corner portion 32 facing upward and exposed to the space of the middle mold 16 or the lower mold. After the molds are clamped, the high-speed steel scrap, which is the same material as the blades 23, is heated and melted and poured into the mold to cast the body 24 integral with the blades 23. At this time, a part of the corner portion 32 of each blade 23 is melted by the heat of the melt, and the melt flows into the small hole 33, so that the casting integration with the body 24 is firmly performed. After the mold is opened, unnecessary portions are cut out from the body 24 to form a disc-shaped body 24 that is integral with the blade 23 and has a center hole 27 at the center as shown in FIGS. .

  Thereafter, a drive hole 28 is provided around the center hole 27 of the body 24 by drilling. Further, the blade 23 is cut to form a plurality of blade portions 22, 22,. Thus, the spiral bevel gear cutter 21 as shown in FIGS. 8 and 9 is manufactured.

  In the second embodiment as well, as in the first embodiment, only the blade portion 22 of the spiral bevel gear cutter 21 is formed by cutting the blade 23 made of expensive high-speed steel. Therefore, it is possible to reduce the amount of chips as compared with the Muku type, and the high-speed steel scrap, which is the same material as the blade 23, is melted to cast the body 24 integral with the blade 23. Therefore, there is an effect that resources can be reused. Particularly, in the case of the second embodiment, since one blade portion 22 is constituted by one substantially quadrangular prism blade 23, a plurality of blade portions 2, 2,. The total weight and chips of the blade 23 can be reduced as compared with the case where the ring-shaped blade 3 is used, and the product price can be further reduced.

(Third embodiment)
FIG. 13 shows a hob cutter 41 as a cutting tool according to a third embodiment of the present invention, and this hob cutter 41 performs gear cutting with a plurality of blade portions 42, 42,. It is.

  The hob cutter 41 includes a plurality of blades 43, 43,... Made of high-speed steel that respectively constitute a predetermined number (five in the figure) of blade portions 42, 42,... Arranged in a line along the axial direction. It consists of a cylindrical body 44 that is integrally cast with the blade 43 using high-speed steel scrap that is the same material as the blade 43. The blades 43 are provided on the outer peripheral surface of the body 44 at predetermined intervals in the circumferential direction thereof, and are cut after the body 44 is cast to form the blade portions 42.

  Next, a method for manufacturing the hob cutter 41 will be described with reference to FIGS. 14 and 15 in addition to FIG. First, a plurality of rod-shaped blades 43 made of high-speed steel for forming a predetermined number of blade portions 42, 42,. The blade 43 has a constricted portion 46 whose thickness is gradually reduced on one end side in a direction orthogonal to the longitudinal direction, and a pair of corner portions 47 and 47 that are pointed laterally at positions close to the end of the constricted portion 46. (See FIG. 14).

  Then, as shown in FIG. 14, a plurality of prepared blades 43, 43,... Are exposed in the mold 52 having the core 51, and the constricted portion 46 and the corner portion 47 are exposed in the space of the mold 52, respectively. Insert it in the state you let it. After the mold 52 is clamped, the high-speed steel scrap, which is the same material as the blade 43, is heated and melted and poured into the mold 52 to cast the body 44 integral with the blade 43. At this time, since a part of the corner portion 47 of the blade 43 is melted by the heat of the melt, the casting integration with the body 44 is firmly performed. After the mold 52 is opened, unnecessary portions are cut out from the body 44 to form a cylindrical body 44 integrated with a plurality of blades 43, 43,... As shown in FIG.

  Thereafter, each of the blades 43 is cut to form a plurality of blade portions 42, 42,. Thus, the hob cutter 41 as shown in FIG. 13 is manufactured.

  And also in the manufacturing method of such a hob cutter 41, only the blade part 42 is expensive among the hob cutters 41 similarly to the manufacturing method of the spiral bevel gear cutters 1 and 21 according to the first and second embodiments. Since the blade 43 made of high-speed steel is cut and formed, chips can be reduced compared to the Muku-shaped one, and scrap of high-speed steel, which is the same material as the blade 43, is melted. Since the body 44 integral with the blade 43 is cast, it is possible to reuse resources and reduce the product price. Furthermore, the rigidity of the blade portion 42 can be secured to the same level as that of the Muku shape, and it is a matter of course that the cutting accuracy can be improved.

(Fourth embodiment)
16 and 17 show a cutting tool 61 according to the fourth embodiment of the present invention. This cutting tool 61 constitutes a part of a rotary cutting tool commonly referred to as a fork cutter or a finger cutter, and has a fork-like or other special-shaped groove formed by a plurality of blade portions 62, 62,. Is to do.

  As shown in FIGS. 18 and 19, the cutting tool 61 includes a plurality of strip-like blades 63, 63,... Made of high-speed steel that constitute each blade 62, and the same material as the blade 63. The disc-shaped body 64 is integrally cast with the blade 63 using high-speed steel scrap. The blades 63 are arranged at equal intervals by a predetermined angle in the circumferential direction in a state in which each side surface of the body 64 is inclined forward in the rotation direction of the cutting tool 61 with respect to the radial direction at the peripheral portion of the body 64. Between the left and right side surfaces of the body 64, one blade 63 is disposed between two adjacent blades 63, 63. The blade 63 is cut after the body 64 is cast to form a blade portion 62. The blade portion 62 has a cutting blade 65 extending from the tip end side of the blade 63 along the leading edge in the rotational direction. Have. In FIG. 16, the outer shape of each blade 63 on the front side surface of the body 64 is indicated by hatching.

  And the manufacturing method of the said cutting tool 61 is the same as the case of the 1st thru | or 3rd embodiment, and the some blade-plate-shaped braid | blade 63,63, ... which consists of high speed steel which comprises each blade part 62, respectively. The blades 63 are inserted into a mold in a predetermined state, and then a high-speed steel scrap made of the same material as the blades 63 is melted and injected into the mold to form a disk-shaped integral with the blade 63. The body 64 is cast, and after the body 64 is cast, each blade 63 is cut to form the blade portion 62. Moreover, according to this manufacturing method, it is needless to say that the same effects as those of the first to third embodiments can be obtained.

  The present invention is not limited to the first to fourth embodiments described above, but includes other various forms. For example, in the first embodiment, the plurality of blade portions 2, 2,... Of the spiral bevel gear cutter 1 are configured by one ring-shaped blade 3, and in the second embodiment, a plurality of spiral bevel gear cutters 21 are provided. Are configured by separate substantially quadrangular prism blades 23, 23,..., But the present invention is not limited to those of both the embodiments, and among the plurality of blades, 2 One or three blade portions may be configured by separate blades.

  In each of the above embodiments, the case where high-speed steel is used as the material for the blades 3, 23, 43, 63 and the bodies 4, 24, 44, 64 has been described. Of course, the present invention can be similarly applied to the case where an alloy or alloy steel is used, and it is possible to reuse resources.

  Further, in the first and second embodiments, the case where the present invention is applied to a spiral bevel gear cutter, the third embodiment is applied to a hob cutter, and the fourth embodiment is applied to a fork cutter. Needless to say, the present invention can be similarly applied to other cutting tools such as an end mill cutter and a milling cutter.

It is a front view of the spiral bevel gear cutter which concerns on the 1st Embodiment of this invention. It is sectional drawing in the AA of FIG. It is the side view which cut | disconnected the right half from the centerline of the blade used for manufacture of the said spiral bevel gear cutter. It is an enlarged view of the cross-sectional part of the said blade. It is sectional drawing for demonstrating the casting process among the manufacturing processes of the said spiral bevel gear cutter. It is a front view of the spiral bevel gear cutter raw material of the state taken out from the casting_mold | template. It is sectional drawing in the BB line of FIG. FIG. 3 is a view corresponding to FIG. 1 showing a second embodiment. It is sectional drawing in CC line of FIG. (A) is a top view of a braid | blade, (b) is the same front view. FIG. 7 is a diagram corresponding to FIG. 6. It is sectional drawing in the DD line | wire of FIG. It is a perspective view of the hob cutter which concerns on 3rd Embodiment. It is sectional drawing for demonstrating the casting process among the manufacturing processes of the said hob cutter. It is sectional drawing of the hob cutter raw material of the state taken out from the casting_mold | template. It is a front view of the cutting tool which concerns on 4th Embodiment. It is sectional drawing in the EE line | wire of FIG. It is an expanded sectional view in the FF line of FIG. It is an expanded sectional view in the GG line of FIG.

1,21 Spiral bevel gear cutter (cutting tool)
2, 22, 42, 62 Blade part 3, 23, 43, 63 Blade 12a, 12b, 32, 47 Corner part 18, 52 Mold 41 Hob cutter (cutting tool)
61 Cutting tool

Claims (3)

A manufacturing method of a cutting tool having a plurality of blade parts,
Preparing a blade having a predetermined shape constituting each of the blade parts,
After inserting this blade into the mold, casting a melt of the same material as the blade into the mold to cast a body integral with the blade;
A method of manufacturing a cutting tool, comprising: a step of cutting a blade after casting of a body to form a blade portion.   2. The method for manufacturing a cutting tool according to claim 1, wherein the blade and the scrap are both made of high speed steel.   The method for manufacturing a cutting tool according to claim 1 or 2, wherein the blade has a corner portion at a portion embedded in the body in a casting process.

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