JPH0740016U - Drilling tool with indexable insert - Google Patents

Abstract

(57) [Abstract] [Purpose] A drilling tool with a throw-away tip that reduces the burden on the cutting edge 8b of the throw-away tip 8 on the outer peripheral side during cutting and does not clog chips when the tool is pulled out after machining. provide. [Structure] A center drill 5 is provided at the tip of the tool body 1, and the tips 7 on the inner and outer peripheral sides of the diamond shape,
8 is detachably fixed, and the tips 7 and 8 thereof are slightly inclined toward the outer edges of the cutting edges 7b and 8b.
b is projected a little longer than the blade tip 8b, and is cut by the tip blade portion 7a of the tip 7 on the inner circumference side before the tip blade portion 8a of the tip 8 on the outer circumference side, and the tip 8 on the outer circumference side is cut.
The burden on the blade edge 8b of the blade is reduced, and the inclination of the blade edge 8b of the tip 8 on the outer peripheral side prevents clogging of cutting chips between the blade edge 8b and the processed hole wall when the tool is pulled out. .

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a drilling tool with a throw-away tip.

[0002]

[Prior art]

 Conventionally, as a drilling tool with a throw-away tip, a center drill protruding from the tip surface of the tool body is fixed to the tip of the tool body, and cutting is performed in the radial direction on the outer peripheral side of the center drill. In some cases, the inner and outer indexable inserts were mounted.

In the above-mentioned drilling tool with a throw-away tip, a work piece is cut by a center drill, and the outer peripheral side portion of the work piece is cut by a plurality of throw-away chips. At this time, the outer diameter of the hole to be machined on the workpiece is cut by the outer throw tip, and the outer peripheral part of the bottom of the hole is cut. Cutting is performed between the cutting parts by the throw-away tip and the center drill on the outer peripheral side of the hole.

[0004]

[Problems to be solved by the device]

 In the conventional drilling tool with a throw-away tip described above, the tool body of the throw-away tip on the outer and inner circumferences goes from the tip of the tool body toward the axial direction of this tool or to the outer circumferential side, and the shank side, that is, the base end side of the tool body. Since the tip was inclined downward, it was difficult to transmit the cutting resistance of the throw-away tip on the outer peripheral side to the outside, and the hole to be machined did not expand, resulting in chip clogging when the tool was pulled out after machining. In addition, since the workpieces are cut at the same time by the throw-away tips on the outer and inner circumference sides, there is a problem in that the load on the cutting edge of the throw-away tips on the outer circumference increases.

The present invention solves the above-mentioned problems and enables the tool to be smoothly withdrawn after machining without causing chip clogging, and the burden on the cutting edge of the throwaway tip on the outer peripheral side during machining. The purpose of the present invention is to provide a drilling tool with a throw-away tip that can be machined well and that can use all the blades of the throw-away tip on the outer and inner circumferences formed in the shape of a rhombus or square without hindrance. .

[0006]

[Means for Solving the Problems]

 As described above, the present invention is directed to a drilling tool having a center drill and an inner peripheral side and an outer peripheral side throw-away tip at the tip of the tool body. The outer throw-away inserts are detachably fixed to the tool body by slightly tilting the tip-end blades toward the outer circumference of these inserts, with the tips of the tips slightly inclined. The outer cutting edge of the throw-away tip on the inner side of the cutting edge is projected slightly longer than the tip surface of the tool body to form a notch on the outer circumference of the center drill, and the notch on the inner circumferential side is formed in this notch. The inner blade portion of is engaged with the inner blade portion of the outer periphery of the center drill.

[0007]

[Action]

 The drilling tool with a throw-away tip according to this invention has a diamond-shaped or square fixed to the tip of the tool body. The tips of the throw-away inserts on the inner circumference side are made to project slightly longer than the tips of the throw-away inserts on the outer circumference, so that they are slightly longer than the tip surface of the tool body. The tip side edge of the throw-away tip processes the hole in the workpiece before the tip side edge of the throw-away tip on the outer peripheral side. It is possible to reduce the load, especially the load at the beginning of processing can be significantly reduced, and good processing can be performed.

Further, since the tip side blade portion of the throw-away tip on the outer peripheral side is slightly inclined toward the outer peripheral side of the tool body so that the cutting resistance is easily transmitted to the outside and the hole is enlarged. , When the tool is pulled out after cutting, the cutting dust can be pulled out smoothly without being clogged between the throw-away tip on the outer peripheral side and the machined hole wall.

[0009] Furthermore, the insertable inserts on the inner circumference side and the outer peripheral side, which are made of the same shape of the diamond or square throw-away tip, are detachably fixed to the tip of the tool body, and the cutting edge parts of these throw-away tips are attached. If the tool wears due to machining, all four cutting edges of each throw-away tip can be used instead of the unmachined cutting edge.

In this invention, a notch is formed on the outer circumference of the center drill, and an inner blade located on the tip side of the throw-away tip on the inner circumference is engaged with the notch, and this inner blade is Since it is embedded in the outer periphery of the center drill, when performing cutting with the tip side blade of the throw-away insert on the inner side, the inside blade, especially the tip side edge of this blade section, is cut by the center drill. It protects and prevents wear and allows the entire inner blade to be used without any problems (see Fig. 6).

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. As shown in each of FIGS. 1 to 3, the tool main body 1 includes a shaft portion with a large-diameter flange portion 3 on a tip side of a shank 2 provided with a pair of flat cut portions 2a for side locks. 4 are integrally formed.

The shaft portion 4 is formed with two tip pockets 4a extending from the tip toward the shank 2 side, that is, the end side to near the flange portion 3 at equal intervals in the circumferential direction. It is formed in a substantially V shape with the depth gradually widening toward the portion 3. Further, the shaft portion 4 is formed with a flat surface 4b in which the ridgeline of the outer periphery of the front side wall of the chip pocket 4a is removed, and the tip end portion thereof is formed with an inclined portion 4c whose removal amount increases toward the tip end. Both chip pockets 4a are formed substantially symmetrically with respect to the rear side wall.

A recess 4e and a mounting hole 4d connected to the recess 4e are provided in the center of the tip of the shaft portion 4 concentrically with the center of the tool body 1 along the axial direction, and a small-diameter shank portion 5a of the center drill 5 is provided. Is fitted into the mounting hole 4d, the step portion 5d is supported on the bottom of the recess 4e, the small diameter shank portion 5a is screw-fitted from the outer peripheral side to the shaft portion 4 and is detachably fixed by the lock screw 6, and the center drill 5 The blade tip portion 5b of the shaft portion 4 is projected from the tip of the shaft portion 4, and the end portions of the two twisted grooves 5c provided between the blade tip portions 5b are respectively connected to the bottom portions of the tip portions of the two chip pockets 4a. .

An inner peripheral side recess 4f and an outer peripheral side recess 4g are formed on the rear wall of the chip pocket 4a at the tip of the shaft portion 4, and the inner peripheral side and outer peripheral side throw-away tips are formed in these recesses 4f and 4g. 7 and 8 are engaged and supported, and the chips 7 and 8 are detachably fixed to the shaft portion 4 by a tightening screw 9 which is passed through the center holes of the chips 7 and 8 from the chip pocket 4a side. The above-described configuration of this embodiment is almost the same as the application No. 5-62147 (filed on November 8, 1993) previously proposed by the applicant.

As shown in FIG. 4, the throw-away tips 7 and 8 on the inner circumference side and the outer circumference side are formed in the same shape of a rhombus in which an obtuse angle α of about 94 ° and an acute angle of about 86 ° face each other. As shown in FIG. 5, the throw-away tip 7 on the inner peripheral side is configured such that a tip side blade portion 7a sandwiching an obtuse angle α 1 on the tip side protrudes from a tip surface 4h of the shaft portion 4 to an extension side of the shaft portion 4, and The tip side blade part 7a is raised about 2 ° with respect to the plane perpendicular to the axial direction of the part 4, that is, the protrusion amount of the shaft part 4 from the tip surface 4h is longer on the outer peripheral side than on the center part of the shaft part 4. It is slightly tilted so that

As shown in FIG. 6, the throw-away tip 8 on the outer peripheral side has a tip-side blade portion 8a that sandwiches an acute angle β 3 on the tip side and protrudes from the tip surface 4h of the shaft portion 4 to the extension side of the shaft portion 4. , The tip side blade portion 8a rises about 2 ° with respect to the plane perpendicular to the axial direction of the shaft portion 4, that is, the protrusion amount from the tip surface 4h of the shaft portion 4 from the center side of the shaft portion 4 to the outer periphery. It is slightly inclined so that the sides are longer. The outer cutting edge 8c that sandwiches the acute angle β on the tip side of the throw-away tip 8 on the outer peripheral side is substantially flat on the distal side with the outer circumference of the shaft portion 4, and is slightly inclined so that the tip side projects from the outer circumference of the shaft portion 4. I am allowed.

The tip edge 7b of the inner throw-away tip 7 has a protrusion amount a which is longer than the tip edge 8b of the outer throw-away tip 8 by about 1 mm. The tip side blade portion 7a of the throw-away tip 7 on the inner peripheral side and the tip side blade portion 8a of the throw-away tip 8 on the outer side are radially arranged at an angular interval of 180 ° in the circumferential direction of the shaft portion 4. The outer peripheral portion of the tip side blade portion 7a and the inner peripheral side portion of the tip side blade portion 8b overlap each other.

A front end surface 4h of the shaft portion 4 is formed in a fan shape, and a front portion 4h ₁ having a thickness substantially equal to that of the inner and outer throwaway tips 7 and 8 is a surface orthogonal to the axis of the tool body 1. The rear portion 4h ₂ is formed as a rearward and downwardly inclined surface toward the rear end side of the shaft portion 4.

A notch 5e is formed on the outer circumference of the center drill 5 so as to face the throw-away tip 7 on the inner circumference side, and the notch 5e has an acute angle on the tip side of the throw-away tip 7 on the inner circumference side. The inner blade portion 7c including the blade tip portion of α is engaged, and the inner blade portion 7c is embedded in the outer peripheral portion of the center drill 5.

The shapes and configurations of the throw-away tips 7 and 8 on the inner and outer circumference sides other than those described above and the attachment of these tips 7 and 8 to the shaft portion 4 of the tool body 1 are the same as those of the conventional holes. It is similar to the drilling tool.

Formed in the tool body 1 are two cutting fluid passage holes 10 from a cutting fluid supply port 10a opening at the end face of the tool body 1 to a discharge port 10b opening at the front end of the tool body 1. The discharge port 10b is arranged close to the twist groove 5c of the center drill 5 on the front side in the direction of rotation of the drill, and the small diameter branch holes 10c are branched from the tips of the two passage holes 10. Is formed in the shaft portion 4, and the branch discharge port 10d provided at the tip of the branch hole 10c is opened in the inclined portion 4c of the tip end of the flat surface 4b provided in the shaft portion 4.

Next, the machining of the workpiece by the drilling tool of the above-mentioned embodiment will be described. The shank 2 of the tool body 1 is detachably fixed horizontally to a non-rotating member such as a tool rest of a horizontal lathe via a holder. A workpiece is detachably fixed to a rotary table provided on the horizontal lathe facing the non-rotating member, and the rotary table is rotated clockwise in FIG. 2 to rotate the workpiece in the same direction. Then, by advancing one of the non-rotating member and the rotating table, one of the drilling tool and the workpiece is advanced, and the center drill 5 of the drilling tool and the throw-away tips 7 on the inner and outer peripheral sides, 8, the workpiece is perforated and cut.

In the cutting process, a cutting fluid supply device provided on the lathe side of the horizontal axis pressure-feeds a cutting fluid such as cutting oil to two cutting fluid passages 10 provided in the tool body 1 from a supply port 10a to perform cutting. The liquid is discharged from a supply port 10b that opens at the tip of the shaft 4 and a branch discharge port 10d that is provided at the tip of the branch hole 10c. The indexable inserts 7, 8 and the cutting part of the workpiece by these are cooled and the processed part is depleted.

Then, at the start of the cutting process, the center portion of the processed portion is first cut by the center drill 5, and then the cutting edge 7b of the throw-away tip 7 on the inner peripheral side of the throw-away tip 8 on the outer peripheral side. By projecting from the tip end surface 4h of the shaft portion 4 of the tool body 1 longer than the cutting edge 8b, the obtuse angled cutting edge 7b of the throw-away tip 7 on the inner peripheral side cuts the intermediate portion of the machined portion, and then the outer peripheral side. The outer peripheral portion of the processed portion is cut by the sharp cutting edge 8b of the throw-away tip 8.

Further, since the tip-side blade portions 7a, 8a of the throw-away tips 7, 8 on the inner and outer circumference sides are slightly inclined upward from the blade tips 7b, 8b, the blade tips 7b, 8b side to the tip end side Cutting will be performed over almost all of the blade portions 7a, 8a. Therefore, at the initial stage of machining, the load transmitted from the inner and outer throw-away tips 7 and 8 to the tool body 1 and the workpiece does not suddenly increase, so that the machining can be performed smoothly.

The cutting process is performed by drilling the tip side blade portion 7a of the throw-away tip 7 on the inner peripheral side before the tip blade portion 8a of the throw-away tip 8 on the outer peripheral side. The burden on the tip side blade portion 8a of the throw-away tip 8 can be reduced, and particularly the initial burden of processing can be significantly reduced.

The cutting speed is determined by the number of revolutions × radius × circumferential ratio, and the throw-away tip 7 on the inner peripheral side is smaller than that on the throw-away tip 8 on the outer peripheral side. Therefore, the cutting edge 7b has an obtuse angle. In some cases, a large load can be endured, and the throw-away tip 8 on the outer peripheral side has a small load even if the cutting speed is high, so that good processing can be performed.

Further, since the tip side blade portion 8a of the throw-away tip 8 on the outer peripheral side is slightly inclined so as to rise to the blade edge 8b toward the outer peripheral side of the tool body 1, it is easy to transmit the cutting resistance to the outside and the hole is enlarged. By doing so, when the tool is pulled out after cutting, the cutting dust does not get stuck between the throw-away tip 8 on the outer peripheral side and the processed hole wall, and the tool can be pulled out smoothly.

Furthermore, the throw-away tips 7 and 8 on the inner peripheral side and the outer peripheral side are constituted by the throw-away inserts of the same shape of the rhombus, and the obtuse-angled cutting edge 7b and the acute-angled cutting edge 8b are formed on the inner peripheral side and the outer peripheral side. Since it is used for the indexable inserts 7 and 8 on the side, if the cutting edges 7b and 8b wear due to machining, remove the tool from the lathe, and then remove the tightening screw 9 from the tool body 1 Not only can it be used by rotating the throw-away inserts 7 and 8 of 180 ° by 180 ° and changing the phase, tightening these inserts 7 and 8 to the tool body 1 again with the screw 9 By replacing the throw-away tips 7 and 8 on the outer peripheral side, unused obtuse-angle and acute-angled cutting edges 7b and 8b can be used, and all four cutting edges of the diamond-shaped throw-away tips can be used.

Then, the notch portion 5e formed on the outer periphery of the center drill 5 is engaged with the inner blade portion 7c including the sharp edged blade tip 7b located on the tip side of the inner peripheral throwaway tip 7, and the blade portion 7c is cut. Since the center drill 5 is made to dig into the outer peripheral portion, the inner blade portion 7c including the acute-angled blade edge 7b portion is used for the center drill when performing the cutting process with the obtuse-angled blade edge 7b portion of the inner peripheral side throw-away tip 7. Since it is protected by 5 and does not wear, the entire obtuse edge can be used without trouble.

Among the cutting edges that are not machined, those that are located on the shank 2 side of the tool body 1 have an obtuse angle that is located on the inner peripheral side of the throwaway tip 8 on the outer peripheral side due to the side wall of the recess 4e of the shaft portion 4. The blade edge 8a is flat with the tip surface 4h of the shaft portion 4 or is located on the shank 2 side thereof, so that it does not wear.

Further, since the inner blade portion 7c of the throw-away tip 7 on the inner peripheral side is made to bite into the notch portion 5e provided on the outer periphery of the center drill 5, the center drill 5 and the throw-away tip on the inner peripheral side are provided. Since the tip 7 and the throw-away tip 8 on the outer peripheral side overlap with each other, the entire portion of the tip 8 on the center side of the cutting edge 8b can be cut.

The cutting powder obtained by cutting the workpiece with the cutting edge 5b of the center drill 5 enters the chip pocket 4a through the twist groove 5c of the drill 5, and is machined with the throw-away tips 7 and 8 on the inner and outer circumference sides. The cutting powder obtained by cutting the object also enters the chip pocket 4a, and the cutting powder that has entered these is discharged outside the drilling tool together with the cutting fluid.

In the drilling tool according to this embodiment, the shank 2 is mounted on a rotating shaft of a machine tool via a holder, and the shank 2 is rotated together with the rotating shaft to detachably fix a workpiece on a table of the machine tool. Non-rotating, and by advancing one of the rotary shaft and the table, drilling the workpiece with the center drill 5 and the inner and outer throw-away tips 7 and 8 in substantially the same way as the lathe processing described above. Can be cut. The drilling tool according to this embodiment can be used for both horizontal and vertical machine tools.

In the present invention, the inner and outer throw-away tips are not limited to the diamond-shaped ones described above, and square shaped throw-away tips may be used. It is possible to process using the entire cutting edge without exchanging the throw-away tip between the outer side and the outer side.

In this invention, the shape and configuration of the shank of the tool body can be changed as appropriate, and one cutting fluid passage hole is provided from the supply port provided on the end face of the tool body to the tip of the tool body. It is formed along the direction, the tip is branched into multiple branch holes, and the cutting fluid is discharged from the branch discharge port that opens at the tip of these branch holes. The cooling fluid supply means can be changed as appropriate as long as cooling and lubrication of the side and outer peripheral side drills and the machined part of the workpiece by these can be performed.

In this invention, two throw-away tips on the inner circumference side and two throw-away tips on the outer circumference side may be alternately provided at equal intervals in the circumferential direction, for a total of four. Further, the tool main body can be appropriately changed by fixing a center drill and a separate head for attaching the throw-away tip to the tip of the shaft portion without forming the tool body integrally.

[0038]

[Effect of device]

 As described above, the drilling tool with a throw-away tip according to the present invention is designed such that the tip side blades of the throwaway tips on the inner and outer sides of the diamond or square fixed to the tip of the tool body are attached to the outer side of the tool body. The tip of the throw-away tip on the inner circumference side is slightly longer than the tip of the throw-away tip on the outer circumference so that the tip of the throw-away tip on the inner circumference projects slightly longer than the tip surface of the tool body. By making a hole in the workpiece on the tip side of the throw-away tip on the inner circumference side before making a hole in the work piece before the tip side of the throw-away tip on the outer circumference side, The load can be reduced, especially the load at the beginning of processing can be significantly reduced, and good processing can be performed.

Further, since the tip side blade portion of the throw-away tip on the outer peripheral side is slightly inclined toward the outer peripheral side of the tool main body so that the cutting resistance is easily transmitted to the outside and the hole is enlarged. , When the tool is pulled out after cutting, the cutting dust can be pulled out smoothly without being clogged between the throw-away tip on the outer peripheral side and the machined hole wall.

Further, the throw-away tips on the inner peripheral side and the outer circumferential side, which are made of the same throwaway tips having the same shape as a rhombus or a square, are detachably fixed to the tip of the tool main body, and the blade tips of these throwaway tips are attached. If the tool wears due to machining, all four cutting edges of each throw-away tip can be used instead of the unmachined cutting edge.

In this invention, a notch is formed on the outer periphery of the center drill, and an inner blade located on the tip side of the throw-away tip on the inner periphery is engaged with this notch, and the inner blade is Since it is embedded in the outer periphery of the center drill, when performing cutting with the tip side blade of the throw-away insert on the inner side, the inside blade, especially the tip side edge of this blade section, is cut by the center drill. It protects and prevents wear, and the entire inner blade can be used without any problems.

[Brief description of drawings]

FIG. 1 is a side view showing a drilling tool with a throw-away tip according to an embodiment of the present invention.

FIG. 2 is a front view of the drilling tool shown in FIG.

FIG. 3 is a rear view of the drilling tool shown in FIG.

FIG. 4 is a side view of a throw-away tip used in the drilling tool shown in FIG.

FIG. 5 is an explanatory view of a mounting state of the throw-away tip on the inner peripheral side of the shaft portion of the tool body of the drilling tool shown in FIG.

FIG. 6 is an explanatory view of the attachment state of the throw-away tip on the outer peripheral side to the shaft portion of the tool body of the drilling tool shown in FIG.

[Explanation of symbols]

1 Tool body 2 Shank 4 Shaft part 4a Tip pocket 4b Flat surface 4c Inclined part 4e Recessed part 4h Tip surface 4h ₁ Front part 5 Center drill 5a Shank part 5b Blade tip part 5c Twisted groove 5e Notch part 7 Inner peripheral throwaway tip 7a Tip side blade part 7b Blade edge 7c Inner side blade part 8 Outer side throw away tip 8a Tip side blade part 8b Blade edge 8c Outer blade part 9 Tightening screw 10 Cutting fluid passage hole 10c Branch hole

Claims (1)

[Scope of utility model registration request] 1. An inner peripheral side and an outer peripheral side for fixing a center drill projecting from the front end surface of the tool body to the tip part of the tool body, and cutting in a radial direction with respect to the outer peripheral side of the center drill. In the drilling tools with throw-away inserts, each of which is equipped with the throw-away inserts, inserts the inner and outer throw-away inserts of the same shape in the shape of a rhombus or square into the tip end of the insert ascending toward the outer circumference. Each of the blades is slightly tilted and detachably fixed to the tool body.The outer cutting edge of the throw-away tip on the inner circumference side is slightly removed from the tip surface of the tool body than the outer cutting edge of the throw-away tip on the outer circumference side. By projecting long, a notch is formed on the outer periphery of the center drill, and the inner blade of the throw-away tip on the inner peripheral side is engaged with this notch, A drilling tool with a throw-away tip, characterized in that the inner cutting edge is embedded in the outer periphery of the center drill.