JP2004255533A - Throwaway tipped drill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throwaway tipped drill whose coupling on a holder body side is not worn after repetitive mounting/dismounting of a cutting head so that a long service life of the holder body can be realized. <P>SOLUTION: The throwaway tipped drill consists of the cutting head 2 including a cutting edge 3 at the tip and including the protruding coupling 4 detachable from the holder body 1 at the rear end, and the holder body 1 including a recessed coupling 5 detachable from the protruding coupling 4 of the cutting head 2 at the tip and including a slit 6 for dividing the recessed coupling 5 on a deep end surface of the coupling 5. The holder body 1 has an approximately conical spatial region 8 formed on the holder body 1, having an inner diameter reduced as approaching a holder body axis 7 from a horizontal direction of the axis 7. The approximately conical spatial region 8 is placed to be equally divided by the slit 6, and a tapered thread is formed on the inner wall of the region 8. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a throw-away drill in which a cutting head having a cutting edge at a tip is detachable from a holder body.
[0002]
[Prior art]
Conventionally, a shape as shown in FIG. 6 has been known as an example of a throwaway drill in which a cutting head portion having a cutting edge at a tip is detachable from a holder body. In this case, a mechanism is used in which the convex portion provided on the cutting head portion side is rotationally slid to couple and fix the concave / convex portion by utilizing the elastic deformation of the concave portion at the tip of the holder main body (for example, see Patent Document 1). 1).
[0003]
[Patent Document 1]
Japanese Unexamined Patent Publication No. 2002-501441
[Problems to be solved by the invention]
However, in the conventional throw-away drill as shown in FIG. 6, the sliding portion on the holder body side gradually wears as the cutting head portion is repeatedly attached and detached, and the clamping force of the cutting head portion increases as the use time increases. However, there is a problem that not only the cutting blade but also the holder body must be periodically replaced in spite of the indexable tool.
[0005]
The present invention has been made to solve such a problem of the prior art. Even if the cutting head portion is repeatedly attached and detached, the concave portion coupled to the cutting head portion of the holder body does not wear, and the length of the holder body is reduced. It is an object of the present invention to provide a throw-away drill that can achieve a longer life.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, a throw-away drill according to claim 1 of the present invention includes a cutting head portion having a cutting edge at a front end and a convex connection portion detachably attached to a holder body side at a rear end portion. A throwaway comprising a convex connecting portion of the cutting head portion and a holder main body having a detachable concave connecting portion at a tip end thereof and a slit provided on a rear end surface of the concave connecting portion to divide the concave connecting portion. In the drill, a substantially conical space region is formed in the holder main body such that the inner diameter becomes smaller as approaching the tool main body axis from a lateral direction with respect to the tool main body axis. The slits are arranged so as to be equally divided by the slits, and a tapered screw is formed on an inner wall of the substantially conical space region.
[0007]
According to such a configuration, a wrench tip portion having a conical shape and formed with a taper screw is inserted into the substantially conical space region in which the tapered screw is formed so as to fit into the substantially conical space region. By rotating the wrench in the screw rotation tightening direction, the tip of the wrench advances in the substantially conical space region accompanied by the tapered screw of the holder body, whereby the slit is gradually widened. Since the width of the concave connecting portion at the tip of the holder main body is also increased, the cutting head can be attached and detached without abrading the coupling portion of the holder main body, so that the clamping force of the cutting head is maintained. The life of the holder body can be extended.
[0008]
Further, in the throw-away drill according to claim 2, the convex connecting portion is located at an outer peripheral portion of a convex portion protruding to a rear end side of the cutting head portion, and is substantially perpendicular to an outer peripheral tangential direction and is cut. A locking surface provided so as to face the tool in the reverse rotation direction at the time, and an auxiliary locking surface protruding so as to face the tool rotation direction at the time of cutting on a part of the conical side surface of the convex portion. The concave connecting portion is substantially perpendicular to the outer peripheral tangent direction so as to abut on the locking surface at the apex position of the two walls constituting the concave connecting portion, and faces the tool rotating direction during cutting. And an auxiliary lock receiving surface protruding so as to face a part of the inner wall of the wall in the reverse rotation direction of the tool during cutting so as to contact the auxiliary lock surface. It is characterized by having.
[0009]
According to this configuration, it is possible to prevent the cutting head from being displaced in the tool rotation direction and the reverse rotation direction during cutting by utilizing the elastic force of the concave connecting portion that is about to tighten.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0011]
1 to 4 show an embodiment of the present invention. FIG. 1 is an exploded perspective view of a tip portion of a throw-away drill according to the embodiment, FIG. 2 is a side view of a main part of a holder body, and FIG. FIG. 4 is a rear end view of the cutting head.
[0012]
As shown in FIGS. 1 to 3, the indexable drill according to the present embodiment has a cutting head 3 having a cutting blade 3 at a front end and a convex connecting portion 4 detachable from a holder main body 1 at a rear end. 2 and a concave connecting portion 5 detachable from the convex connecting portion 4 of the cutting head portion 2 at the front end portion, and a slit 6 for dividing the concave connecting portion 5 at a deep end face of the concave connecting portion 5. And a substantially conical space region in which the inside diameter of the holder body 1 decreases as the holder body 1 approaches the holder body axis 7 from a lateral direction with respect to the holder body axis 7. 8, the substantially conical space region 8 is arranged so as to be equally divided by the slit 6, and a tapered screw is formed on the inner wall of the substantially conical space region 8. It has been.
[0013]
Here, as shown in FIG. 3, a tapered screw is formed in the substantially conical space region 8 in which the tapered screw is formed so as to fit into the substantially conical space region 8. By inserting the tip of the wrench 9 and turning the wrench 9 in the direction of screw tightening, the tip of the wrench 9 advances in the substantially conical space region 8 accompanied by the tapered screw of the holder body 1. Thus, the width of the slit 6 is gradually widened, and the width of the concave connecting portion 5 at the tip of the holder main body 1 is also widened. In this state, the convex connecting portion 4 of the cutting head portion 2 can be set at the mounting position of the concave connecting portion 5 of the holder main body 1. Does not slide. Therefore, the pinching force of the cutting head 2 can be maintained for a long period of time and the life of the holder body 1 can be extended without abrasion and wear of the connecting surface of the holder body 1. Further, since the substantially conical space region 8 is arranged so as to be equally divided by the slits 6, the wrench 9 can evenly spread the two divided walls of the space region 8. In addition, it is possible to prevent excessive stress from being applied to only one of them, and as a result, it is possible to suppress damage to the tapered thread portion.
[0014]
Further, the convex connecting portion is located at the outer peripheral portion of the convex portion projecting to the rear end side of the cutting head portion 2 and is substantially perpendicular to the outer peripheral tangential direction and faces the tool reverse rotation direction 17 during cutting. 4 is substantially perpendicular to the outer peripheral tangential direction so as to abut on the locking surface 11 at the top of the two wall portions 15 constituting the concave connecting portion 5 and at the time of cutting. The rotation of the holder body 1 at the time of cutting is transmitted to the cutting head portion 2 by contact with the locking receiving surface 13 provided so as to face in the tool rotation direction 16 of FIG. As described above, the auxiliary locking surface 12 provided on a part of the conical side surface 10 of the convex portion so as to face the tool rotation direction 16 during cutting, and the inner wall of the wall portion 15 on the concave connecting portion 5 side. Tool reverse rotation direction 1 at the time of cutting so as to abut on the auxiliary locking surface 12 Auxiliary locking receiving surface 14 provided so as to face widening is removed by removing the wrench 9 into which the concave connection portion is inserted, which has been widened by the tapered screw of the space region 8 having a substantially conical shape. It is brought back into contact by canceling the elastic deformation, and the effect of pressing the locking surface 11 more strongly toward the locking receiving surface 13 is obtained. Thus, the cutting head 2 is securely and firmly fixed to the holder main body 1 without being displaced not only in the tool rotation direction 16 during cutting but also in the tool reverse rotation direction 17 during cutting.
[0015]
The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be arbitrarily made without departing from the object of the invention.
[0016]
【The invention's effect】
As described above, the indexable drill according to the first aspect has a cutting head portion provided with a cutting edge at a front end and a convex connecting portion detachable from a holder body side at a rear end portion, and a convex portion of the cutting head portion. And a holder body having a concave connecting portion and a detachable concave connecting portion at a distal end thereof, and a holder main body having a slit for dividing the concave connecting portion at a rear end surface of the concave connecting portion, wherein the holder comprises: A substantially conical space region is formed in the main body such that the inner diameter becomes smaller as approaching the holder main body axis from a lateral direction with respect to the holder main body axis, and the substantially conical space region is uniformly formed by the slit. The tapered screw is formed on the inner wall of the substantially conical space region while being arranged so as to be divided. By inserting a wrench tip having a conical shape and formed with a tapered screw into the substantially conical space region to fit into the substantially conical space region, and turning the wrench in the screw rotation tightening direction. As the tip of the wrench advances in the substantially conical space region to which the taper screw of the holder body is attached, the slit is gradually widened and the width of the concave connecting portion at the front end of the holder body is also widened. Therefore, the cutting head can be attached and detached without abrading the joint portion of the holder main body, so that the holding force of the cutting head can be maintained and the life of the holder main body can be extended.
[0017]
Further, in the throw-away drill according to claim 2, the convex connecting portion is located at an outer peripheral portion of a convex portion protruding to a rear end side of the cutting head portion, and is substantially perpendicular to an outer peripheral tangential direction and is cut. A locking surface provided so as to face the tool in the reverse rotation direction at the time, and an auxiliary locking surface protruding so as to face the tool rotation direction at the time of cutting on a part of the conical side surface of the convex portion. The concave connecting portion is substantially perpendicular to the outer peripheral tangent direction so as to abut on the locking surface at the apex position of the two walls constituting the concave connecting portion, and faces the tool rotating direction during cutting. And an auxiliary lock receiving surface protruding so as to face a part of the inner wall of the wall in the reverse rotation direction of the tool during cutting so as to contact the auxiliary lock surface. By using the elastic force that the concave connecting portion tries to tighten, The cutting head portion can suppress the positional deviation in the tool rotating direction and the reverse rotation direction during cutting.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a tip portion of a throw-away drill according to the present invention.
FIG. 2 is a side view of a main part of the holder body according to the embodiment.
FIG. 3 is a front view of FIG. 2;
FIG. 4 is a rear end view of the cutting head according to the embodiment.
FIG. 5 is a schematic cross-sectional view taken along line AA of FIG. 2 according to another embodiment.
FIG. 6 is an exploded perspective view of the tip of a conventional throw-away drill.
[Explanation of symbols]
1: Holder body 2: Cutting head part 3: Cutting blade 4: Convex connecting part 5: Concave connecting part 6: Slit 7: Holder main body axis 8: Spatial region 9 of substantially conical shape 9: Wrench 10: Conical side surface 11: Locking surface 12: auxiliary locking surface 13: locking receiving surface 14: auxiliary locking receiving surface 15: wall 16: tool rotation direction 17 during cutting 17: tool reverse rotation direction 18 during cutting: clamping direction

Claims (2)

A cutting head part having a cutting blade at the tip and a convex connection part detachably attached to the holder body side at the rear end part, and a concave connection part detachable from the convex connection part of the cutting head part at the tip part. And a holder body provided with a slit for dividing the concave connection portion at a rear end surface of the concave connection portion, wherein the holder main body has an axial line extending from a lateral direction with respect to the holder main body axis. A substantially conical space region is formed such that the inner diameter becomes smaller as approaching .The substantially conical space region is arranged so as to be equally divided by the slit, and the substantially conical space region is formed. A throw-away drill, wherein a tapered screw is formed on an inner wall of the space region. The convex connection portion is provided at an outer peripheral portion of the convex portion protruding to the rear end side of the cutting head portion, is provided substantially perpendicular to an outer peripheral tangential direction, and faces in a tool reverse rotation direction at the time of cutting. Locking surface, and an auxiliary locking surface protruding on a part of the conical side surface of the convex portion so as to face the tool rotation direction at the time of cutting, and the concave connecting portion constitutes the concave connecting portion. The locking receiving surface provided at a top position of the two wall portions to be in contact with the locking surface at a right angle to the outer peripheral tangent direction and facing the tool rotation direction during cutting; and 2. An auxiliary locking receiving surface protruding from a part of an inner wall of the portion so as to face the auxiliary locking surface in a reverse rotation direction of a tool during cutting so as to abut on the auxiliary locking surface. The described throw-away drill.

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