JP2591570Y2 - Drilling tool with indexable insert - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling tool with a throwaway tip having an improved cutting fluid passage hole.

[0002]

2. Description of the Related Art Conventionally, as a drilling tool with a throw-away tip, a center drill having a cutting edge projecting from the tip of the tool body is fitted and fixed to the tip of the tool body, and the center drill is provided at two locations in the circumferential direction of the tool body. In some cases, a chip pocket is formed, and a cutting away cutting tip is fixed to the tip of the rear side wall of the chip pocket.

[0003] In the drilling tool, one cutting fluid passage hole having a supply port opened at the center of the end face of the tool body is formed along the axial direction of the tool body, and the passage hole is formed at the tip end of the tool body. In the center drill, the cutting fluid such as cutting oil is discharged from an appropriate location in the center groove, or provided on the outer periphery of the drill at the tip of the tool body. The cutting fluid is discharged from the plurality of discharge ports to cool the center drill and the machined portion of the workpiece by this, and lubricate the machined portion.

[0004]

In the above-mentioned conventional drilling tool with a throw-away tip, one cutting fluid passage hole is formed in the axial direction concentrically with the center of the tool body, and this passage hole is formed in the tool body. A straight line having the same diameter from the supply port opened on the end face to the tip of the tool body, and branched into a plurality of branch holes such as two at the tip, and a branch hole of the passage hole inclined with respect to the axial direction of the tool body. Since the discharge port is opened at the tip of
Due to the relationship with the strength of the tool body, the diameter of the passage hole and the branch hole cannot be increased so much.
For the book portion, the branch hole of the passage hole is bent, and the resistance of the cutting fluid flowing through the passage hole increases, so that a large amount of the cutting fluid cannot be discharged from the discharge hole, and There is a problem that the supply amount is insufficient.

In view of this, it is conceivable to form two cutting fluid passage holes in the tool body in the axial direction from the supply port to the discharge port in a straight line of equal diameter. However, since the center drill has a small diameter at the tip of the tool body, it is necessary to form the two passage holes close to each other. However, there is a problem that a large amount of cutting fluid cannot be discharged from the discharge port.

This invention solves the above-mentioned problems,
Compared to the conventional one, a large amount of cutting fluid is efficiently supplied from the discharge port to the outer periphery of the center drill and the cutting part of the workpiece without substantially reducing the strength of the tool body, and the amount of cutting fluid supplied It is an object of the present invention to provide a drilling tool with a throw-away tip that can sufficiently satisfy the requirements.

[0007]

According to the present invention, there is provided a throwaway having a center drill provided at a tip portion of a tool body and a throwaway tip provided at two tip pocket rear wall tip portions as described above. In the drilling tool with a tip, the center drill is formed by penetrating two cutting fluid passage holes, each having an opening at a distal end face of the tool body and an opening at a tip end of the tool body, in the axial direction of the tool body. And the passage hole is formed to gradually decrease in diameter from the supply port to the discharge port, and the discharge port is arranged at a position inscribed in the supply port by approaching the center side of the center drill. It is.

[0008]

The drilling tool with a throw-away tip according to the present invention has two cutting fluid passage holes formed in the tool body.
By gradually reducing the diameter from the supply port opening at the end face of the tool body to the discharge port opening at the tip of the tool body,
Since the diameter of the end portion of the passage hole can be considerably large, and the diameter becomes small only at the tip end of the passage hole close to the discharge port, the cutting fluid pumped from the discharge port to the two passage holes is removed. By increasing the pressure at the end of the passage, it is possible to discharge at high speed from the discharge hole, and because the discharge port of the cutting fluid path hole is located closer to the center of the center drill, it is located at a position inscribed in the supply port. The cutting fluid pumped into the passage hole can be discharged linearly with a small resistance without bending, and a large amount of cutting fluid can be supplied from the discharge port.

In addition, the discharge port of the cutting fluid passage hole is located near the center of the drill so as to be in contact with the supply port, so that the center drill is positioned close to the outer periphery of the portion protruding from the tip of the tool body. The cutting fluid can be discharged from the drill, the drill and the cooling of the cutting part of the workpiece by the drill and the lubrication of the processing part can be efficiently performed, and the tip portions near the discharge ports of the two passage holes have small diameters. Therefore, the strength of the tool main body is hardly reduced even when these tips approach the drill mounting holes.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. As shown in each of FIGS. 1 to 4, the tool body 1 has a shaft portion 4 integrally formed with a straight shank 2 via a large-diameter flange portion 3 on the distal end side thereof. In the shank 2, a pair of side lock notches 2a extending from the end to the vicinity of the flange portion 3 are arranged on the upper surface and the side surfaces with their center lines in the width direction provided at 90 ° intervals in the circumferential direction. I have. In addition, the said flange part 3 is formed in the flat surface which the front end side becomes deep and wide.

The shaft portion 4 is formed with two chip pockets 4a extending from the tip end toward the shank 2 to the vicinity of the flange portion 3 at regular intervals in the circumferential direction and in a substantially V-shaped obtuse angle. The tip pocket 4a gradually increases in depth from the tip toward the shank 2, and
a rear side wall 4a ₂ width narrow to a _1, are then gradually wider side walls 4a ₁ before towards the shank 2.

The center line in the width direction of the notch 2a and the outer edge of the rear side wall 4a ₂ of the chip pocket 4a are connected to the rear side wall 4a.
The tip ₂ is shifted 45 ° in the circumferential direction at the tip, and is aligned in the circumferential direction at the end.

Further, the shaft portion 4 has a tip pocket 4a.
The flat surface 4b formed deleting the ridgeline of the front wall 4a ₁ periphery of, these tip is formed is inclined portion 4c that many deletion amount toward the tip. Note that both chip pockets 4a is is formed substantially symmetrically with respect to the rear wall 4a _2.

A concave portion 4e is formed at the center of the tip of the shaft portion 4.
And a mounting hole 4d connected thereto are provided along the axial direction concentrically with the center of the tool body 1, the small-diameter shank portion 5a of the center drill 5 is fitted into the mounting hole 4d, and the step portion 5d is
e, the small-diameter shank portion 5a is detachably fixed to the shaft portion 4 by a lock screw 6 screwed from the outer peripheral side, and the cutting edge portion 5b of the center drill 5 is projected from the tip of the shaft portion 4. , Two twist grooves 5 provided between the cutting edge portions 5b
The ends of c are connected to the bottoms of the tips of the two tip pockets 4a, respectively.

A tip pocket 4a is provided at the tip of the shaft portion 4.
A recess 4f in the side wall 4a ₂ after, these recesses 4f
The cutting insert 7 for cutting parallelogram is supported, and the chip 7 is removably fastened and fixed to the shaft portion 4 by a fastening screw 8 passed through the hole of the tip 7 from the tip pocket side. The blade 7 a formed on the outer peripheral edge of the shaft 7 is slightly projected from the tip of the shaft 4.
One of the tips 7 is disposed so as to bite into the outer periphery of the center drill 5, and the other of the tips 7 has the blade portion 7 a slightly projecting from the outer periphery of the tip end of the shaft portion 4. The outer peripheral side portion of the portion 4 and the central side portion of the shaft portion 4 of the other chip 7 are arranged so as to slightly overlap in the radial direction of the shaft portion 4.

As shown in FIG. 1 to FIG.
The cutting fluid supply port 9a is opened at the end face of the cutting tool, and two cutting fluid passage holes 9 having the cutting fluid discharge port 9b opened at the tip of the tool main body 1 are provided on both sides of the center of the center drill 5 at both ends. The two passage holes 9 are provided so as to face each other, and the supply holes 9a
The outlet 9b is formed in a shape having a gradually decreasing diameter toward the outlet 9b, and the outlet 9b is formed closer to the center of the drill so as to be inscribed in the supply port 9a. Then, the discharge port 9b, respectively are opened in the drill rotation direction front side to the spiral flute 5c of the center drill 5, a front wall 4a ₁ tip of each chip pocket 4a, the cross-section semicircular open to insert pocket 4a It is notched by a short length in the axial direction, and is arranged at a position close to the outer periphery of the center drill 5.

Further, a small-diameter branch hole 9c that branches off from the distal end of the two passage holes 9 and extends obliquely toward the distal end side is formed in the shaft portion 4, and the distal end of the branch hole 9c is provided in the shaft portion 4. The branch discharge port 9d located at the inclined portion 4c of the flat surface 4b is opened.

Next, the processing of the workpiece by the drilling tool of the above-described embodiment will be described. The shank 2 is inserted into a holder (not shown), a lock bolt is screwed into a screw hole provided in the shank 2, and the shank 2 is fastened to one of the side lock notches 2a to fix the shank 2 to the holder. Attach to the rotating shaft of the machine.

By driving the rotating shaft, the drilling tool is moved as shown in FIG.
The counterclockwise rotation of one of the drilling tool and one of the workpiece and the drilling tool, which is removably fixed in advance to a table provided on the machine tool so as to face the rotary shaft, is one of the rotary shaft and the table. The workpiece is drilled by the center drill 5 and the indexable insert 7 of the drilling tool.

In this cutting process, a cutting fluid such as cutting oil is opened to the end face of the shank 2 into two cutting fluid passage holes 9 provided in the tool body 1 by a cutting fluid supply device provided on the machine tool side. The cutting fluid is fed from the supply port 9a and discharged from the discharge port 9b opened at the end of the shaft portion 4 through the passage hole 9 and the cutting fluid is diverted to the branch hole 9c branched from the passage hole 9. This is performed while discharging from the branch discharge port 9d provided at the tip.

[0021] Then, the discharge port 9b respectively provided on the distal end of the two cutting fluid passage hole 9, the front wall 4a ₁ tip of each chip pocket 4a, the cross-section semicircular open to insert pocket 4a side Since the cutting fluid is notched by a short length in the axial direction, the cutting fluid flowing through the passage hole 9 is discharged from the discharge port 9b while being slightly inclined toward the center of the front end of the shaft portion 4, and is discharged from the discharge port 9b. Because it is close to the outer periphery of the center drill 5, it can be efficiently supplied to the outer periphery of the drill 5 and the machined portion of the workpiece by the drill 5.

The cutting fluid diverted to the branch hole 9c is formed by the throw-away tips 7 and the blade portions 7a of these tip pockets 7 from the branch discharge port 9d because the branch holes 9c are inclined forward and obliquely outward. It can be efficiently supplied to the cutting part of the workpiece.

Further, in this embodiment, since the two cutting fluid passage holes 9 are formed with a gradually decreasing diameter from the supply port 9a at the end face of the tool body 1 to the discharge port 9b at the tip, the supply port is provided. The cutting fluid pressure-fed to the passage hole 9 from the discharge port 9 a
Since the pressure is high and the speed is high at the end of the passage hole 9 close to b, even if the cutting fluid is diverted to the branch hole 9c, the cutting fluid discharged from the discharge port 9b linearly connected to the supply port 9a is conventionally used. Higher flow rates and higher flow rates. In the drilling tool according to the present invention having a small outer diameter, the branch hole may be omitted.

In the drilling tool according to the above-described embodiment, the shank 2 is mounted on a non-rotating member such as a tool post of a lathe on a horizontal axis via a holder, and the workpiece is rotated without rotating the drilling tool. The processing may be performed by rotating a table on which the table is detachably fixed and moving one of the non-rotating member and the table.

In the present invention, the configuration and shape of the shank of the tool body can be changed as appropriate, such as by providing one notch for side lock, and the tip pocket is parallel to the axial direction of the shaft like the conventional one. The cutting insert for cutting also has an inner end on the outer periphery of the center drill and the outer end slightly protrudes from the outer periphery of the shaft. Can be changed.

[0026]

As described above, the drilling tool with a throw-away tip according to the present invention has two cutting fluid passage holes formed in the tool main body from the supply port opening at the end face of the tool main body. By gradually reducing the diameter toward the discharge port that opens at the tip end of the passage hole, the end portion of the passage hole can be considerably large in diameter, and the small diameter is only at the tip of the passage hole close to the discharge port. Therefore, the cutting fluid pressure-fed from the discharge port to the two passage holes can be discharged at high speed from the discharge hole by increasing the pressure at the tip of the passage, and the discharge port of the cutting fluid passage hole can be centered. Since the cutting fluid is disposed at a position inscribed in the supply port by being brought close to the center of the drill, the cutting fluid pumped into the passage hole can be discharged linearly with a small resistance without bending, and a large amount of cutting can be performed from the discharge port. Liquid can be supplied.

Therefore, according to the present invention, the cutting fluid can be efficiently and sufficiently supplied from the discharge hole to the outer periphery of the center drill and the cutting portion of the workpiece by the drill, and the tool can be rotated at a high speed. Workpieces can be processed efficiently by such means.

Further, as described above, the present invention arranges the discharge port of the cutting fluid passage hole toward the center of the drill so as to be inscribed in the supply port, thereby protruding from the tip of the tool body of the center drill. Cutting fluid can be discharged from a position close to the outer periphery of the drilled portion, the drill and the cooling of the cutting portion of the workpiece by the drilling and the lubrication of the machining portion can be efficiently performed, and the two passage holes can be formed. Since the tips near the discharge port have a small diameter, the strength of the tool main body hardly decreases even when these tips approach the drill mounting holes.

[Brief description of the 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 plan view of the drilling tool shown in FIG. 1;

FIG. 3 is a front view of the drilling tool shown in FIG. 1;

FIG. 4 is a rear view of the drilling tool shown in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Tool main body 2 Shank 3 Flange part 4 Shaft part 4a Tip pocket 4a ₁ Front side wall 4a ₂ Back side wall 4b Flat surface 4c Flat surface inclined part 4d Drill mounting hole 5 Center drill 5a Shank part 5b Blade tip part 5c Twist groove 7 Throw away Tip 7a Blade 9 Cutting fluid passage hole 9a Supply port 9b Discharge port 9c Branch hole 9d Branch discharge port

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B23B 51/06 B23B 51/00

Claims (1)

(57) [Scope of request for utility model registration] 1. A center drill having a cutting edge projecting from the tip of the tool body is fitted and fixed to the tip of the tool body, and tip pockets are formed at two locations in the circumferential direction of the tool body. In a drilling tool with a throw-away tip, each of which has a cutting-away tip for cutting fixed at its tip, two cutting fluids having a supply port opened at the end face of the tool body and a discharge port opened at the tip of the tool body. Passage holes are provided on both sides of the center drill by penetrating in the axial direction of the tool body, and the passage holes are formed with a gradually decreasing diameter from the supply port toward the discharge port, and the discharge port is formed at the center of the center drill. A hole-drilling tool with a throw-away tip, wherein the hole-cutting tool is disposed at a position inscribed in the supply port.