JP4816041B2 - Insert type drill and insert - Google Patents

Description

  The present invention relates to an insert type drill in which an insert having a cutting edge at its tip is detachably mounted on the tip side of a drill body, and an insert used for the insert type drill.

  2. Description of the Related Art Conventionally, as a cutting tool for drilling a workpiece, an insert type drill in which an insert having a cutting edge at the tip is detachably attached to the tip of a drill body is used. In this insert type drill, when the cutting blade is worn out by cutting the workpiece, only the insert can be replaced and used, and the cost of using the drill can be reduced. (See Patent Document 1 and Patent Document 2.)

  In this type of insert type drill, an insert mounting seat having a concave groove shape recessed toward the rear end side of the drill body is formed at the tip of the drill body having a substantially cylindrical shape rotated about the axis. The inner surface of the insert mounting seat faces the tip of the drill body and is perpendicular to the axis of the drill body, and is opposed to each other across the axis so as to face the inside of the drill body in the radial direction while intersecting the bottom surface. And a pair of clamp surfaces that sandwich the insert, and a clamp screw that elastically deforms the pair of clamp surfaces so as to be close to each other. A plurality of fitting grooves extending in parallel with the insertion direction of the insert are formed on the clamp surface.

  An insert having a cutting edge is attached to the insert mounting seat. An example of a conventional insert is shown in FIG. The insert 1 is made of a hard material such as cemented carbide, and has an outer shape of a substantially pentagonal flat plate shape. A pressed surface 2A disposed opposite to the clamp surface is formed on a part of the pentagonal surface 2. Has been.

  A U-shaped groove 3 cut out in a U-shape from the center of the pentagonal surface 2 of the insert 1 toward the rear end side of the insert 1 (upper side in FIG. 5) is formed. The clamp screw is inserted into the clamp screw.

  Of the pentagonal surface 2 of the insert 1, the region opposite to the U-shaped groove 3 of the pressed surface 2 </ b> A faces the front side in the drill rotation direction when the insert 1 is mounted on the insert mounting seat. The portion to be arranged is a rake face 2B. A cutting edge 5 is formed at the intersection ridge line portion between the rake face 2B and the tip face 4 of the insert 1, that is, at the ridge part on the tip side of the rake face 2B.

A plurality of protrusions 6 extending in parallel with the insertion direction U when the insert 1 is inserted into the insert mounting seat are formed on the pressed surface 2A.
At the rear end side portion (insertion direction U front side portion) of the insert 1 of the pressed surface 2A, the height of the protruding portion 6 is formed so as to gradually decrease toward the front side in the insertion direction U. The vicinity of the rear end surface 8 of the insert 1 on the surface 2 </ b> A is an inclined flat surface 7 without the protrusion 6.

  Such an insert 1 is inserted into an insert mounting seat formed on the tip side of the drill body, and is elastically deformed by a clamp screw so that a pair of clamp surfaces of the insert mounting seat are close to each other, and a pressed surface of the insert 1 By pressing 2A, the insert 1 is clamped and fixed.

The insert type drill configured as described above is rotated around the axis O and fed in the direction of the axis O to perform cutting so as to form a processed hole in the workpiece.
JP 2005-169572 A JP 2004-330391 A

  By the way, in the conventional insert type drill, when the insert is inserted into the insert mounting seat, the protrusion formed on the pressed surface of the insert is inserted into the fitting groove formed on the clamp surface of the insert mounting seat. It was necessary to adjust the position so that it took some time for unskilled workers. In addition, there is a problem that the state of mounting of the insert varies depending on the operator.

  For example, if it inserts from the direction slightly inclined with respect to the insertion direction, it becomes impossible to smoothly insert the protrusion into the fitting groove. Here, when the insert is inserted with an excessive force, the rear end surface of the insert and the bottom surface of the insert mounting seat are mounted without contacting. When cutting is performed in such a state where the insert is mounted, the cutting force cannot be sufficiently received, and the cutting edge of the insert may be shaken, and the insert may be lost. In particular, when the material to be cut is a difficult-to-cut material, the cutting resistance is increased and the insert is likely to be broken, so that this insert type drill may not be used.

Further, when the insert is inserted with an excessive force as described above, the fitting groove and the ridge are deformed, and there is a possibility that the drill body and the insert cannot be used again.
Furthermore, since the position of the insert is not stable, there has been a problem that it is impossible to form a processed hole with high accuracy.

  In particular, as shown in FIG. 5, when the vicinity of the insert rear end surface of the pressed surface is an inclined flat surface without a protrusion, the direction in which the protrusion is arranged in the insert mounting seat. There is a problem that the insert easily moves in a direction (perpendicular to the insertion direction U), and it becomes difficult to align the protrusion and the fitting groove.

  The present invention has been made in view of such circumstances, and the insert can be easily and reliably attached to the insert mounting seat, and the insert is stably attached to suppress the fluctuation of the cutting edge. It is an object of the present invention to provide an insert type drill that can be used and an insert used therefor.

In order to solve the above-mentioned problems, the present invention provides an insert mounting seat having a concave groove shape opened at a tip surface of a drill body at a tip portion of a drill body rotated about an axis, and the insert mounting seat. Is provided with a pair of clamp surfaces and a clamp screw that elastically deforms the clamp surfaces so as to be close to each other. The insert mounting seat has a cutting edge at the tip and is disposed to face the clamp surfaces. An insert type drill in which an insert having a pair of pressed surfaces is inserted and the clamp surfaces are brought close to each other by the clamp screw so that the insert is sandwiched and fixed. The clamp surface is formed with a fitting groove extending in parallel with the insertion direction of the insert, and the pressed surface of the insert Is formed with a protrusion that extends parallel to the insertion direction and can be fitted to the fitting groove, and the protrusion is fitted on the front side of the protrusion in the insertion direction. A guide portion for guiding to the groove portion is provided, and the guide portion includes a pair of guide surfaces constituting the guide portion connected to both side surfaces sandwiching the top portion of the ridge portion on the front side in the insertion direction. The guide surfaces are formed so as to be close to each other as they go toward each other, and the pair of guide surfaces have a concave curved surface shape that is concave inward in the width direction of the ridge portion, and the guide portion has a width of the ridge portion. It is characterized in that it is formed such that the width is gradually reduced toward the front side in the insertion direction, and the reduction ratio of the width is gradually reduced toward the front side in the insertion direction .

  According to the insert type drill having this configuration, since the guide portion is formed in the insertion direction front side portion of the protrusion portion formed on the pressed surface of the insert, when inserting the insert into the insert mounting seat, By the guide portion, the protruding ridge portion is guided to the fitting groove portion formed on the clamp surface of the insert mounting seat, and the protruding portion can be surely fitted into the fitting groove portion.

  Therefore, the insert can be easily and reliably inserted, and the time required for the insert mounting operation can be reduced. In addition, since the insert can be easily mounted, it is possible to suppress variations in the mounting state of the insert by the operator. Furthermore, since the fitting groove and the ridge are securely fitted, the position of the insert can be stably fixed, the runout of the cutting edge of the insert due to cutting resistance can be prevented, and the machining hole can be accurately formed. Can do.

Then, a pair of guide surfaces constituting the guide portion connected to both side surfaces sandwiching the top portion of the ridge portion are formed on the guide portion so as to be close to each other as they move forward in the insertion direction. The pair of guide surfaces form a concave curved surface that is concave inward in the width direction of the ridge portion, and the guide portion is gradually reduced as the width of the ridge portion moves toward the front side in the insertion direction. In addition, by forming the width reduction rate so as to gradually decrease toward the front side in the insertion direction , when inserting the insert, it becomes easier to fit the protrusion into the fitting groove, The protrusion and the fitting groove can be reliably fitted.

  In addition, in the insertion direction front side portion of the pressed surface, the height of the protruding portion is formed so as to gradually decrease toward the front side in the insertion direction, thereby forming an insert mounting having a concave groove shape. When inserting the insert into the seat, the ridges do not collide with the end surface of the insert mounting seat on the tip side of the drill body, that is, near the edge of the clamp body on the tip side of the drill body, making it easy to insert the insert. Can be done.

Further, a screw insertion portion through which the clamp screw is inserted is formed in the insert, and the screw insertion portion is a hole portion in which the front side portion in the insertion direction of the insert is closed. Thus, compared with the case where the screw insertion portion is formed in a U-shaped groove shape, the portion where the insert is notched to form the screw insertion portion can be made smaller, and the strength of the insert can be ensured.
For this reason, for example, the chip generated by the cutting blade is carried to the rear end side of the insert, and the insert can be prevented from being damaged when the chip is bitten in the vicinity of the screw insertion portion. Can be achieved.

Further, the insert according to the present invention is configured so that the protrusion is formed on the front side in the insertion direction of the protrusion formed on the pressed surface of the insert into the fitting groove formed on the clamp surface. A guide portion for guiding is provided, and a pair of guide surfaces constituting the guide portion connected to both side surfaces sandwiching the top portion of the ridge portion are directed to the front side in the insertion direction. The guide surfaces are formed so as to be close to each other, and the pair of guide surfaces have a concave curved shape that is concave inward in the width direction of the ridge portion, and the guide portion has a width of the ridge portion in the insertion direction. It is characterized in that the width is reduced gradually toward the front side, and the reduction ratio of the width is gradually reduced toward the front side in the insertion direction .
The insert having this configuration can be easily and reliably inserted into the insert mounting seat formed on the drill body.

  As described above, according to the present invention, an insert-type drill capable of easily and surely mounting the insert on the insert mounting seat and stably mounting the insert and suppressing the fluctuation of the cutting blade, and the insert drill can be used. The insert used can be provided.

Hereinafter, an insert type drill according to an embodiment of the present invention will be described with reference to the accompanying drawings. 1 and 2 show an insert which is an embodiment of the present invention. 3 and 4 show an insert-type drill according to an embodiment of the present invention. As shown in FIG. 3, this insert-type drill 10 is rotated about an axis O and has a generally cylindrical shape. And an insert 21 that is detachably attached to the distal end side of the drill body 11.

  As shown in FIGS. 3 and 4, on the outer periphery of the drill main body 11, a pair of holes that open at the front end surface of the drill main body 11 and twist toward the rear side of the drill rotation direction T toward the rear end side of the drill main body 11. The chip discharge grooves 12 are formed to be 180 ° rotationally symmetric with respect to the axis O.

A recessed groove-shaped insert mounting seat 14 that opens at the distal end surface of the drill body 11 and is recessed toward the rear end side of the drill body 11 extends in the diameter direction passing through the axis O at the distal end portion 13 of the drill body 11. Is formed.
The insert mounting seat 14 faces the tip side in the direction of the axis O and is perpendicular to the axis O, and stands upright from the bottom surface 14A, and is parallel to the axis O and intersects the tip of the drill body 11. A pair of clamp surfaces 14B is provided, and is formed so as to open in a “U” shape toward the distal end surface of the drill body 11 in a side view along the bottom surface 14A and the clamp surface 14B.

  More specifically, the insert mounting seat 14 is notched in the diameter direction passing through the axis O between the wall surfaces facing the front side of the drill rotation direction T on the tip side of the chip discharge groove 12 at the tip portion 13 of the drill body 11. It is formed as described above, and is communicated with the chip discharge groove 12 at both ends in the extending direction M (diameter direction with respect to the axis O).

  Further, by forming such a groove-shaped insert mounting seat 14 at the tip portion 13 of the drill body 11, the tip portion 13 of the drill body 11 is formed into a first tip portion 13A and a second tip portion 13B. The bottom surface 14A of the insert mounting seat 14 is positioned between the first tip portion 13A and the second tip portion 13B, and the insert mounting seat is located on the first tip portion 13A side. 14, one of the pair of clamp surfaces 14B is positioned, and the other of the pair of clamp surfaces 14B is positioned on the second tip portion 13B side.

  Further, a thinning surface 26 of the insert 21 to be described later is formed on the tip surface of the drill body 11 so that a cross ridge line portion between the tip surface and the wall surface facing the rear side in the drill rotation direction T in the chip discharge groove 12 is cut out. And a pair of clamp surfaces 14B in the insert mounting seat 14 that intersect with the tip end surface of the drill body 11 also intersect with these body side thinning surfaces 15. .

  Here, in each of the pair of clamp surfaces 14B in the insert mounting seat 14, a plurality of fitting groove portions 16 extending along the direction of the axis O are arranged at predetermined intervals in a direction orthogonal to the axis O, and the axis O The cross section perpendicular to the waveform is formed in a wave shape. Here, in each of the pair of clamp surfaces 14B, the fitting groove portion 16 is formed in a portion (a portion where the front end side intersects the main body side thinning surface 15) connected to the rear end side of the main body side thinning surface 15 in the axis O direction. It is not formed but is formed in a planar shape.

  When the drill body 11 is viewed from the front end side in the axis O direction, as shown in FIG. 4, the intersecting ridge lines between the pair of clamp surfaces 14B and the body-side thinning surface 15 are each linear, and The intersecting ridge line portion between the pair of clamp surfaces 14 </ b> B and the tip surface excluding the main body side thinning surface 15 forms a wave shape by the plurality of fitting grooves 16.

  Further, an insertion hole for screwing a clamp screw 40 to be described later is formed in the distal end portion 13 of the drill body 11. This insertion hole is formed so as to extend in the L direction shown in FIG. 4, that is, to extend in the diameter direction passing through the axis O and intersecting the insert mounting seat 14, and to penetrate the tip portion 13. The side end portions are opened in the outer peripheral surface of the first tip portion 13A and the outer peripheral surface of the second tip portion 13B, respectively.

  The insertion hole is formed so as to extend in the diameter direction passing through the axis O as in the case of the insert mounting seat 14, but the extending direction L is shown in FIG. 4 when viewed from the front end side in the axis O direction. Thus, it is configured not to be parallel to the width direction N of the insert mounting seat 14 which is a direction orthogonal to the extending direction M of the insert mounting seat 14 but to be inclined with respect to the width direction N of the insert mounting seat 14. Yes.

  Further, as shown in FIG. 3, the drill body 11 is provided with a cutting oil hole 17 extending along the axis O, and communicates with the cutting oil hole 17 so as to connect the distal end side of the drill body 11 and the drill body 11. A cutting oil supply hole 18 extending outward in the radial direction is formed.

Next, the insert 21 mounted on the insert mounting seat 14 will be described. The insert 21 is made of a hard material such as a cemented carbide, and as shown in FIGS. 1 and 2, the outer shape thereof has a substantially pentagonal flat plate shape.
A through-hole 23 is formed in the central portion of the pentagonal surface 22 so as to penetrate obliquely with respect to the thickness direction of the insert 21. The through-hole 23 is a clamp screw insertion portion through which a clamp screw 40 described later is inserted, and the inner diameter thereof is larger than the outer diameter of the clamp screw 40.

When the insert 21 is mounted on the insert mounting seat 14, a portion facing the front side of the drill rotation direction T of the pair of pentagonal surfaces 22 of the insert 21 is a rake face 22B, and the rear side of the drill rotation direction T is The facing portion is a pressed surface 22 </ b> A that comes into contact with the clamp surface 14 </ b> B of the insert mounting seat 14. That is, the pentagonal surface 22 of the insert 21 is formed with a through hole 23 at a central portion disposed in the vicinity of the axis O, and the scoop surface 22B and the pressed surface 22A are disposed with the through hole 23 interposed therebetween. It is. Here, the stepped surface 22A is provided with a step so as to be more convex than the rake surface 22B.
The rake face 22B is formed in a concave curved shape in which the central portion in the width direction is recessed toward the rear side of the drill rotation direction T, and is formed so as to gradually twist toward the rear side of the drill rotation direction T toward the rear end side. Has been.

  The tip surface 24 of the insert 21 is formed in an isosceles triangle shape that gradually recedes from the axis O toward the outer peripheral side in a state where the insert 21 is mounted on the insert mounting seat 14. A cutting edge 25 is formed at the intersecting ridge line portion between the surface 24 and the rake surface 22B. Here, since the rake face 22B is formed in a concave curved surface shape, when the insert 21 is viewed from the front end face 24 side, the cutting edge 25 is located on the rear side in the drill rotation direction T as shown in FIG. It has a concave concave curve.

  Moreover, the front end surface 24 of the insert 21 includes a first flank 24A continuous to the drill rotation direction T rear side of the cutting edge 25, and a second flank 24B continuous to the drill rotation direction T rear side of the first flank 24A. It has a multi-stage shape composed of For this reason, the cutting edge 25 is provided with a relief that increases in a multistage manner as it goes rearward in the drill rotation direction T.

On the tip side of the rake face 22B, in the state where the insert 21 is mounted, the axis O positioned at the center of the tip face 24 of the insert 21 from the vicinity where the rake face 22B and the other part of the pentagonal face 22 of the insert 21 intersect. The region up to the adjacent position intersects with the inner peripheral end side of the cutting blade 25 by being obliquely cut out toward the front side of the drill rotation direction T as it goes toward the tip end side in the axis O direction. A thinning surface 26 is formed so as to extend toward the axis O located at the center of the leading end surface 24 and reach a portion of the pentagonal surface 22 other than the rake surface 22B.
As a result, a thin cutting edge 27 having a substantially linear shape extending toward the axis O located at the center of the distal end surface 24 is disposed at a portion on the inner peripheral end side of the cutting edge 25.

  Further, each of the pair of outer peripheral surfaces facing the outer peripheral side of the insert 21 has a margin portion 28 having an arc shape centering on the axis O with the front side of the drill rotation direction T intersecting the outer peripheral side ridge portion of the rake face 22B. And a marginal portion 28 that is continuous to the rear side of the drill rotation direction T, and has a second surface 29 having a circular arc shape having a one-step radius smaller than the radius of the circular arc formed by the margin portion 28.

Furthermore, a plurality of protrusions 30 extending in parallel with the insertion direction U of the insert 21 are formed on the pressed surface 22A of the pentagonal surface 22 so as to be arranged at predetermined intervals in a direction orthogonal to the insertion direction U. Yes. In each of the pressed surfaces 22A, a portion connected to the rear end side of the thinning surface 26 (a portion where the front end side intersects the thinning surface 26) is formed in a flat shape without the protrusion 30 being formed.
Here, in this embodiment, the insertion direction U of the insert 21 and the axis O direction of the drill main body 11 are matched, and the protrusion 30 formed on the pressed surface 22A of the insert 21 is an insert mounting seat. It is set as the cross-sectional wave shape with which the fitting groove part 16 formed in 14 clamp surfaces 14B can be fitted. However, the top of the corrugation formed by the protrusion 30 is formed in a flat shape.

  Then, at the front side of the pressed surface 22A in the insertion direction U (the rear end side of the insert 21, upper side in FIG. 1), the width of the ridge 30 is gradually reduced as it goes toward the front side of the insertion direction U. A guide portion 31 formed as described above is arranged. Furthermore, in the part in which this guide part 31 was formed, it is formed so that the height of the protrusion part 30 may become low gradually as it goes to the insertion direction U front side.

  Specifically, in this guide portion 31, a pair of guide surfaces 31A and 31B constituting the guide portion 31 connected to both side surfaces sandwiching the top portion of the ridge portion 30 are close to each other in the insertion direction U front side. The width is gradually reduced, and the intersection ridgelines of the guide surfaces 31A and 31B connected to the top are gradually lowered. In addition, the pair of guide surfaces 31A and 31B has a concave curved surface shape that is concave on the inner side in the width direction of the ridge portion 30, so that the reduction ratio of the width in the guide portion 31 is on the front side in the insertion direction U. It gets smaller gradually as you go.

  In the insert 21 having such a configuration, the thickness direction of the insert 21 is set in the diametric direction in which the insert mounting seat 14 extends, with respect to the insert mounting seat 14 having a concave groove shape formed in the tip portion 13 of the drill body 11. In an orthogonal state, it is inserted into the insert mounting seat 14 toward the front side in the insertion direction U (in this embodiment, toward the rear end side in the axis O direction). At this time, the ridge 30 formed on the pressed surface 22A of the insert 21 is inserted into the fitting groove 16 formed on the clamp surface 14B of the insert mounting seat 14 so as to be inserted.

  As a result, the rear end surface 32 of the insert 21 is disposed opposite to the bottom surface 14A of the insert mounting seat 14 and brought into close contact with each other, and the rake face 22B of the insert 21 is opened into the chip discharge groove 12 to rotate the drill. The pressed surface 22A of the insert 21 is disposed opposite to the clamp surface 14B of the insert mounting seat 14 and is formed on the protrusion 30 and the clamp surface 14B formed on the pressed surface 22A. The fitted groove portions 16 are fitted to each other.

  At this time, a portion (a portion where the front end side intersects the thinning surface 26) connected to the rear end side of the thinning surface 26 formed in the insert 21 in a flat shape is the clamp surface 14 </ b> B of the insert mounting seat 14. A portion that is formed in a planar shape connected to the rear end side of the main body side thinning surface 15 (a portion where the front end side intersects with the main body side thinning surface 15) is disposed opposite to each other, and the front end side of the portions formed in a flat shape The thinning surface 26 and the main body side thinning surface 15 that are connected to each other are continuous.

Next, the clamp screw 40 is screwed into the insertion hole provided on the distal end side of the drill main body 11 so as to penetrate the through hole 23 of the insert 21 inserted in the insert mounting seat 14.
Thereby, the front-end | tip part 13 of the drill main body 11 is elastically deformed so that a pair of clamp surface 14B of the insert mounting seat 14 may mutually adjoin, and these pair of clamp surfaces 14B strengthen the to-be-pressed surface 22A of the insert 21. The inserted ridges 30 and the fitting grooves 16 are firmly brought into close contact with each other, and the insert 21 is mounted on the insert mounting seat 14.

  The insert type drill 10 configured in this way is rotated about the axis O and fed in the direction of the axis O to perform cutting so as to form a processed hole in the workpiece.

  According to the insert-type drill 10 according to the present embodiment, the width of the ridge 30 on the insertion direction U front side (the rear end side of the insert 21) of the ridge 30 formed on the pressed surface 22 </ b> A of the insert 21. Since the guide portion 31 formed so as to be gradually reduced as it goes toward the front side in the insertion direction U (the rear end side of the insert 21) is disposed, this guide is inserted when the insert 21 is inserted into the insert mounting seat 14. The protruding portion 30 of the insert 21 is guided by the portion 31 to the fitting groove portion 16 formed on the clamp surface 14B of the insert mounting seat 14, and the protruding portion 30 and the fitting groove portion 16 are securely fitted. be able to.

  Therefore, the insert 21 can be easily and reliably inserted, and the time and labor required for the mounting work of the insert 21 can be greatly reduced. Moreover, since the insert 21 can be easily mounted, variations in the mounting state of the insert 21 by the operator can be suppressed. Furthermore, since the fitting groove 16 and the protrusion 30 are securely fitted, the position of the insert 21 can be stably fixed, the runout of the cutting edge 25 of the insert 21 due to cutting resistance can be prevented, and the machining hole can be formed. It can be formed with high accuracy.

  Moreover, since the height of the protrusion 30 is formed so as to gradually become lower toward the front side in the insertion direction U (the rear end side of the insert 21), when the insert 21 is inserted into the insert mounting seat 14. The protrusion portion 30 does not collide with the end surface of the opening end of the drill body 11 of the insert mounting seat 14, that is, the vicinity of the ridge portion on the tip end side of the drill body 11 of the clamp surface 14 </ b> B, and the insert 21 can be easily inserted. be able to.

Moreover, since the through-hole 23 penetrated so as to be inclined with respect to the thickness direction of the insert 21 is formed as the clamp screw insertion portion provided in the insert 21, the clamp screw insertion portion is formed in a U-shaped groove shape. Compared with the conventional insert, the portion where the insert 21 is cut out to form the clamp screw insertion portion can be made smaller, and the strength of the insert 21 can be ensured.
Therefore, the chips generated by the cutting blade 25 are conveyed to the rear end side of the insert 21, and the insert 21 can be prevented from being damaged by being bitten near the clamp screw insertion portion. Can be planned.

The insert drill according to the embodiment of the present invention has been described above. However, the present invention is not limited to this embodiment, and can be appropriately changed without departing from the technical idea of the present invention.
For example, the description has been made assuming that an insert having a substantially pentagonal flat plate shape is mounted. However, the present invention is not limited to this, and the shape of the insert can be arbitrarily determined. Any insert having a pressed surface to be pressed may be used.

  Moreover, although the fitting recessed part formed in the clamp surface of insert mounting seat was demonstrated as what was formed so that it might extend in parallel with the axis line O, it is not limited to this, The direction which inclines with respect to the axis line O You may form so that it may extend. In this case, the protrusion formed on the pressed surface of the insert is also formed to extend in a direction inclined with respect to the axis O in a state where the insert is mounted.

It is a side view of an insert which is an embodiment of the present invention. It is a X direction arrow line view in FIG. It is a side view of an insert type drill which is an embodiment of the present invention. It is a Y direction arrow directional view in FIG. It is a side view of the insert with which the conventional insert type drill is mounted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Insert type drill 11 Drill main body 14 Insert mounting seat 14B Clamp surface 16 Fitting groove part 21 Insert 22A Pressed surface 23 Through hole 25 Cutting edge 30 Projection part 31 Guide part 40 Clamp screw

Claims (4)

An insert mounting seat having a concave groove shape opened to the tip surface of the drill body is formed at the tip of the drill body rotated about the axis. The insert mounting seat has a pair of clamp surfaces and the clamp surface. And a clamp screw that elastically deforms so as to be close to each other,
The insert mounting seat is inserted with an insert having a pair of pressed surfaces that have a cutting edge at the tip and are arranged to face the clamp surface,
An insert type drill in which the insert is clamped and fixed by bringing the clamp surfaces close to each other by the clamp screw,
The clamp surface provided in the insert mounting seat is formed with a fitting groove extending in parallel with the insertion direction of the insert,
On the pressed surface of the insert, a protrusion that extends in parallel with the insertion direction and can be fitted with the fitting groove is formed.
On the front side in the insertion direction of the ridge portion, a guide portion for guiding the ridge portion to the fitting groove portion is provided ,
In the guide portion, a pair of guide surfaces constituting the guide portion connected to both side surfaces sandwiching the top portion of the ridge portion are formed so as to be close to each other as they move forward in the insertion direction. The guide surface has a concave curved surface that is concave on the inner side in the width direction of the ridge portion, and the guide portion gradually reduces as the width of the ridge portion moves toward the front side in the insertion direction. The insert type drill is characterized in that the reduction ratio of the width is formed so as to gradually become smaller toward the front side in the insertion direction . Wherein in the inserting direction front portion of the pressed surface, according to claim 1, characterized in that it is formed so as gradually lowered in accordance with the height of the ridge is directed to the insertion direction front side Insert type drill. A screw insertion portion through which the clamp screw is inserted is formed in the insert, and the screw insertion portion is a hole in which the insertion direction front side portion of the insert is closed. The insert type drill according to claim 1 or claim 2 . An insert attached to the insert type drill according to any one of claims 1 to 3 ,
On the front side in the insertion direction of the protruding portion formed on the pressed surface, a guide portion that guides the protruding portion to the fitting groove formed on the clamping surface is provided ,
In the guide portion, a pair of guide surfaces constituting the guide portion connected to both side surfaces sandwiching the top portion of the ridge portion are formed so as to be close to each other as they move forward in the insertion direction. The guide surface has a concave curved surface that is concave on the inner side in the width direction of the ridge portion, and the guide portion gradually reduces as the width of the ridge portion moves toward the front side in the insertion direction. The insert is characterized in that the reduction ratio of the width is formed so as to gradually become smaller toward the front side in the insertion direction .

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