JP2004082306A - Drill and throw-away tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drill keeping high working accuracy in drilling by using a throw-away tip mounted on a drill body. <P>SOLUTION: This drill has the throw-away tip 2 mountable and demountable to a drill body rotatable on an axis. The throw-away tip 2 has an approximately flat shape, and mounted on a recessed groove formed on the tip face of a drill body. Faces 2d at both sides in the direction intersecting with the axis of the throw-away tip 2 are exposed from the drill body when the throw-away tip is mounted in the recessed groove, and the faces 2d are provided with two marginal parts 21, 22 kept into contact with a work. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a drill having a throwaway tip that can be attached to and detached from a drill body, and a throwaway tip.
[0002]
[Prior art]
Conventionally, a detachable indexable tip (hereinafter referred to as “tip”) has been attached to a drill body having a concave groove on the tip surface, and the disposable tip is disposable without repolishing. By doing so, there is a drill that saves time for tool re-grinding and reduces tool change time.
[0003]
FIG. 8 shows an example of a conventional drill. In FIG. 8, the drill DJ has a drill body 100 and a throw-away tip 101 that can be attached to and detached from the drill body 100. A concave groove 103 is formed in the distal end surface 102 of the drill body 100 so as to open to the distal end surface 102. At the time of drilling, the drilling is performed while a part of the surface 104 of the indexable insert 101 arranged in the concave groove portion 103 exposed from the drill body 100 is applied to a workpiece W which is a workpiece. .
[0004]
[Problems to be solved by the invention]
By the way, the following problems have arisen in the conventional drill as described above.
In the case of drilling the work W using the drill DJ, the hole H is bent immediately before the hole H is penetrated, that is, when the drill DJ comes out of the hole H of the work W (see arrow C in FIG. 8). ) A phenomenon has occurred, and a problem has arisen that the machining accuracy of the drill for the workpiece W is reduced.
[0005]
The present invention has been made in view of such circumstances, and when drilling using a throwaway tip mounted on a drill body, a drill capable of maintaining high processing accuracy and a throwaway detachable from the drill. The purpose is to provide chips.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a drill according to the present invention is a drill having a drill body rotatable around an axis, and a throwaway tip detachable from the drill body, wherein the throwaway tip is substantially flat. The drill body has a concave groove portion at the tip end thereof, in which the throw-away tip can be arranged, and the surfaces of both sides in the direction intersecting with the axis of the throw-away tip arranged in the concave groove portion are the drill. Each of the side surfaces of the throw-away tip is provided with at least two margin portions for hitting a workpiece.
The throw-away tip of the present invention is a substantially flat-shaped throw-away tip that can be inserted into a concave groove portion opened in the distal end surface of the drill body, wherein both surfaces in the direction intersecting with the insertion direction when inserted into the concave groove portion have It is set so as to be exposed from the drill main body, and at least two margin portions corresponding to the workpiece are provided on each of the two side surfaces.
[0007]
According to the present invention, in a throw-away tip mounted on a drill main body, at least two margin portions are provided on each of the surfaces exposed from the drill main body to form a double margin structure. There are at least four margins corresponding to the workpiece. Accordingly, the position of the drill with respect to the workpiece is stabilized even during rotation, and thus it is possible to suppress the occurrence of bending of the hole when drilling.
That is, in the related art, when drilling, the drilling is performed while applying a part of the surface of the throw-away insert exposed from the drill body. Therefore, the position in the direction intersecting with the axis of the rotating drill becomes unstable. However, in the present invention, the rotating drill is provided by providing at least two, and a total of four, margin portions of the throw-away tip on one exposed surface. When the position in the direction intersecting the axis of the hole is stably penetrated, the occurrence of bending of the hole can be suppressed.
[0008]
In the drill according to the aspect of the invention, the concave groove portion is formed along a plane including the axis so as to open on a distal end surface of the drill body, and a guide groove extending in a direction along the axis line is formed on an inner surface of the concave groove portion. A protrusion is provided on the outer surface of the throw-away tip opposite to the inner surface of the concave groove portion, the convex portion being engageable with the guide groove. According to this, a serration structure is formed by the guide groove and the convex portion, and the insert of the throw away tip is inserted into the concave groove portion so as to slide from the front end side while the convex portion is engaged with the guide groove, and the throw away tip is drilled. It can be easily attached to the main body, and the alignment accuracy of the indexable insert with respect to the drill main body can be improved. Also, the serration structure allows the drill body to rotate and the workpiece to be machined by the throw-away tip, so that the drill body and the throw-away tip do not shift, and the rotational force of the drill body is throw-away. It is reliably and efficiently transmitted to the chip.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the drill and the indexable insert of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing an embodiment of a drill and a throw-away tip according to the present invention. FIG. 1 (a) is a side view seen from a Y direction, and FIG. 1 (b) is a side view seen from an X direction. It is. 2 is a view of FIG. 1A viewed from the front end side (Z direction side), and FIG. 3 is a cross-sectional view taken along the line AA of FIG. 1B.
[0010]
In FIG. 1, a drill D includes a drill main body 1 rotatable around an axis O, and a throw-away tip (hereinafter, referred to as “tip”) 2 detachably attached to the drill main body 1. The tip 2 is made of a hard material such as a cemented carbide and has a cutting edge 2a. On the rear end side of the drill body 1, a shank portion 1a, which is a large diameter portion, is provided. On the other hand, a pair of chip discharge grooves 4 that are open on the distal end surface 3 of the drill body 1 are formed on the distal end side of the drill body 1. As shown in FIG. 2, the chip discharge grooves 4 are twisted to the opposite sides with respect to the axis O and to the rear side in the drill rotation direction T at the time of drilling around the axis O toward the rear end. Is formed in a spiral shape.
[0011]
A groove 6 is formed at the tip of the drill body 1. The concave groove portion 6 is formed along a plane including the axis O, and is formed so as to open to the distal end surface 3 of the drill body 1. The concave groove portion 6 is formed so as to cut out in a diametrical direction with respect to the axis O between the wall surfaces facing the drill rotation direction T at the distal end side of the chip discharge groove 4, and the axial line O faces the distal end side. And a pair of opposed inner side surfaces 6b orthogonal to the bottom surface 6a and extending along the axis O. As shown in FIG. 1B, the concave groove 6 is formed so as to open in a U-shape toward the distal end face 3 in a side view, and the chip 2 can be arranged.
[0012]
The chip 2 is formed in a substantially pentagonal flat plate shape, and is arranged in the concave groove portion 6 with its rear end face 2c facing the bottom face 6a. Further, the size of the tip 2 is set such that the surfaces 2 d, 2 d on both sides in the direction intersecting with the axis O are exposed from the drill body 1 when the tip 2 is arranged in the concave groove 6.
[0013]
A channel 5 is formed inside the drill body 1 along the axis O. The flow path 5 is formed so as to communicate the rear end face 8 of the drill body 1 with the bottom face 6 a of the concave groove 6. As shown in FIG. 1A, a processing oil (fluid) is provided to the flow path 5 on the rear end face 8 side of the drill body 1 outside the drill body 1. A processing oil supply unit 9 that can be supplied is connected. The processing oil supplied to the flow path 5 from the processing oil supply unit 9 provided outside the drill body 1 flows from the rear end face 8 of the flow path 5 to the bottom face 6 a of the concave groove portion 6 facing the front end side. It is supposed to.
[0014]
As shown in FIG. 1 and FIG. 2, a recessed recess (cavity) 15 formed by counterboring is formed on the bottom surface 6 a of the recessed groove 6. The search portion 15 is formed so as to be continuous with the front end side of the flow path 5 and has a larger diameter than the flow path 5. When the tip 2 is arranged in the groove 6, the boring portion 15 forms a gap 15 between the drill body 1 and the rear end face 2 c of the tip 2. The gap 15 is used as an oil reservoir for the processing oil supplied from the flow path 5.
[0015]
A guide groove 7 extending in a direction along the axis O is formed on the inner side surface 6 b of the concave groove portion 6. The guide groove 7 is formed by forming a plurality of groove portions extending in a direction along the axis O in a direction intersecting with the axis O, and is formed on each of the pair of inner side surfaces 6b. At this time, the guide groove 7 is not formed on the entire surface of the inner side surface 6b, but is formed from the vicinity of each axis O of the inner side surface 6b to one end in the X direction as shown in FIG. .
[0016]
As shown in FIGS. 1 and 3, the tip 2 has a through-hole 10 formed in the center in the X direction in the thickness direction. The tip portion is set so as to coincide with the through hole 11 drilled in the Y direction at the center portion in the X direction of the tip portion. Each of the through holes 10 and 11 is formed with a female screw, and the drill body 1 and the tip 2 are connected by screwing a fixing member 12 made of a bolt into each of the through holes 10 and 11. Fixed. Here, each of the through holes 10 and 11 is formed at the center in the X direction, and coincides with the axis O.
[0017]
4 is a side view of the throw away tip 2 viewed from the Y direction, FIG. 5 is a view of FIG. 4 viewed from the distal end side, and FIG. 6 is a side view of the throw away tip 2 viewed from the X direction.
As shown in FIGS. 4 and 5, the chip 2 is formed in a substantially pentagonal flat plate shape, and the tip of the chip 2 has an isosceles triangular shape that gradually retreats from the axis O toward the outer peripheral side. (V-shape). A plurality of projections 13 that can be engaged with the guide grooves 7 of the drill body 1 are formed on the outer surface 2 b of the tip 2. The protrusions 13 are formed so as to extend in the direction along the axis O, that is, so that their ridges coincide with the direction of the axis O, and are formed in a plurality in a direction intersecting with the axis O. The protrusion 13 is formed at a position corresponding to the position where the guide groove 7 of the groove 6 is formed when the chip 2 is arranged in the groove 6. That is, the protrusion 13 is formed on each of the pair of outer surfaces 2b, and is formed from the vicinity of each axis O of the outer surface 2b to one end in the X direction.
[0018]
Here, the cutting blade 2a is formed at the intersection ridge line between the tip of the tip 2 and the rake face 20 facing the drill rotation direction T side of both outer side faces 2b of the tip 2. The rake face 20 is an inclined face that gradually narrows toward the rear end side of the chip 2 (see FIG. 4) and gradually recedes toward the opposite outer side face 2b (see FIG. 6). And the convex part 13 is formed in the part other than the rake face 20 of both outer side surfaces 2b.
[0019]
Each of the plurality of protrusions 13 is formed with a tapered portion 30 (30A to 30D) so as to be inclined toward the front side in the insertion direction, that is, toward the rear end surface 2c of the chip 2. That is, the tapered portion 30 is formed so as to reduce the thickness of the chip 2 toward the rear end face 2c side of the chip 2. The formation distances in the insertion direction of the tapered portions 30A to 30D formed on each of the plurality of protrusions 13, that is, the formation distances of the tapered portions 30A to 30D in the Z-axis direction are set to different values. In the present embodiment, the formation distance of each of the tapered portions 30A to 30D is set so as to gradually decrease from the center in the X direction of the outer surface 2b in the direction intersecting with the insertion direction toward the end. That is, the forming distance of the tapered portion 30D at the center in the X direction of the outer side surface 2b is set to be the longest, and the forming distance is set to gradually decrease toward the end in the X direction. Further, each of the distal ends (-Z side) of the tapered portions 30A to 30D is set to be disposed on a linear line M, and the angle between the line M and the X axis is θM. I have. That is, the tapered portions 30A to 30D are chamfered by the same surface. On the other hand, as shown in FIG. 1A, the tip of the drill body 1 is formed in a substantially V-shape when viewed from the side, and the angle between the tip 3 and the X axis is determined by the line M and the X axis. Is substantially the same as the angle θM formed by That is, the forming distance of each of the tapered portions 30A to 30D is set such that the line M set in each of the tapered portions 30A to 30D substantially matches the inclination (shape) of the distal end surface 3.
[0020]
As shown in FIGS. 5 and 6, each of the surfaces 2 d and 2 d exposed from the drill body 1 when arranged in the concave groove portion 6 has a margin portion that hits a work (workpiece) when drilling. A plurality is provided. In the present embodiment, two margin portions are provided: a first margin portion 21 and a second margin portion 22. The first margin portion 21 is provided close to the rake face 20, and is provided so as to be inclined from the tip side to the outer surface 2b side opposite to the rake face so as to conform to the shape of the rake face 20 (FIG. 6). The second margin section 22 is provided substantially in parallel with the first margin section 21. A groove 23 is formed between the first margin 21 and the second margin 22 in parallel with the first and second margins 21 and 22. Here, the margin width h1 of the first margin portion 21 is set to about 3 to 10% of the diameter of the drill body 1, and is preferably set to about 5%. The margin width h2 of the second margin portion 22 is set to 10 to 15% of the diameter of the drill body 1, and is preferably set to about 12%. The width h3 of the groove 23 is set to 5 to 10% of the diameter of the drill body 1, and is preferably set to 12%.
[0021]
By the way, when the tip 2 is disposed in the concave groove portion 6, as shown in FIG. 7, between the convex portion 13 formed in the chip 2 and the guide groove 7 formed in the concave groove portion 6 of the drill body 1. Is set such that a gap portion 14 is formed near the top and valley of each of the plurality of convex portions 13. The gap 14 is set to a size that allows the processing oil to flow, and the processing oil can flow at the front end side and the rear end side of the chip 2. When the chip 2 is disposed in the concave groove 6, The processing oil supplied to the bottom surface 6 a of the groove 6 through the flow path 5 flows through the gap 14. That is, the processing oil supplied to the concave groove 6 via the flow path 5 flows out from the tip end side of the chip 2 through the gap 14. Here, the gap portion 14 is formed only near the top of the protrusion 13 (near the valley of the guide groove 7), and in other portions, the guide groove 7 and the protrusion 13 contact each other. Is set to The gap 15 described above is formed at a position on the bottom surface 6 a of the concave groove 6 corresponding to the joint between the guide groove 7 and the convex 13. That is, when the chip 2 is placed in the concave groove 6, the gap 15 is continuous with the gap 14. Here, the gap 15 formed to have a larger diameter than the passage 5 is formed so as to be continuous with each of the plurality of gaps 14 formed between the guide groove 7 and the projection 13. .
[0022]
Next, a procedure for attaching the tip 2 to the drill body 1 in the drill D having the above-described configuration and an operation at the time of drilling will be described.
First, the rear end face 2c of the chip 2 and the concave groove 6 are opposed to each other. Here, as described above, the angle between the line M and the X-axis, which are set in each of the tapered portions 30A to 30D, and the inclination angle of the distal end surface 3 of the drill body 1 with respect to the X-axis have substantially the same value θM. Is set. When attaching the tip 2 to the drill body 1, the forming direction of the through hole 10 of the tip 2 and the forming direction of the through hole 11 of the drill body 1 are made to coincide with each other, and the tip surface 3 side (opening side) ), The chip 2 is inserted in the + Z direction, that is, in the direction of the axis O (see the arrow S in FIG. 1). Here, in a state where the tip 2 is inserted into the concave groove portion 6, the angle between the line M set by each of the tapered portions 30A to 30D and the X axis, and the inclination angle of the tip end surface 3 of the drill body 1 with respect to the X axis Are set to substantially the same value θM, so that each of the plurality of protrusions 13 formed in the chip 2 and each of the plurality of guide grooves 7 formed in the concave groove 6 are engaged substantially simultaneously. Is done. That is, at the time of the insertion operation, the plurality of projections 13 and the guide grooves 7 are engaged at the same time, so that the insertion operation can be performed smoothly without shaking the chip 2. Then, the chip 2 is arranged in the groove 6 by being further inserted. By inserting the chip 2, the rear end surface 2 c of the chip 2 and the bottom surface 6 a of the concave groove 6 come into contact with each other. The position where the rear end face 2c of the chip 2 comes into contact with the bottom surface 6a of the concave groove 6 is set so that the through hole 10 of the chip 2 and the through hole 11 of the drill body 1 coincide with each other. The tip 2 is connected and fixed to the drill body 1 by inserting the fixing member 12 into the through holes 10 and 11 and screwing the fixing member 12 as a bolt and the through holes 10 and 11 having female threads. .
[0023]
When removing the tip 2 from the drill body 1, the screw between the fixing member 12 and the through holes 10, 11 is unscrewed, and after removing the fixing member 12, the tip 2 is pulled out from the concave groove portion 6. The main body 1 and the chip 2 are separated.
[0024]
After the tip 2 is fixed to the drill body 1, drilling is performed on the work while supplying the processing oil to the flow path 5 of the drill body 1 from the processing oil supply unit 9. The processing oil supplied to the flow path 5 is supplied from the front end of the flow path 5 to the gap 15 as a processing oil reservoir. Since the gap 15 and the gap 14 are continuous, the processing oil is discharged from the tip end side of the chip 2 through the gap 14. In this way, the drilling can be performed while supplying the processing oil to the work.
[0025]
Here, a first margin portion 21 and a second margin portion 22 are provided on the surfaces 2d and 2d of the chip 2 to form a double margin structure. That is, in the drill D that rotates during drilling, the number of margin portions corresponding to the work (workpiece) is two at one surface 2d, and at least four in total. Therefore, even during rotation, the position of the drill 1 in the direction intersecting with the axis O is stable with respect to the workpiece, so that drilling can be performed while suppressing occurrence of bending of the hole when drilling.
[0026]
As described above, by setting the margin portion of the tip 2 to at least two, and a total of four, on one exposed surface 2d, the position in the direction intersecting with the axis of the rotating drill 1 can be stably penetrated. The occurrence of bending of the hole can be suppressed.
[0027]
In this embodiment, two margin portions are provided for one surface 2d, but three or more arbitrary plural portions may be provided. Further, the shape of the groove 23 as viewed from the Z direction can be arbitrarily set, such as a V shape, an arc shape, or a rectangular shape.
[0028]
【The invention's effect】
By setting the margin portion of the throw-away tip to at least two to form a double margin structure, it is possible to perform drilling with a stable position in a direction intersecting with the axis of the drill. Therefore, it is possible to suppress the occurrence of bending of the hole at the time of penetration, and to realize high processing accuracy.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of a drill of the present invention.
FIG. 2 is a view of the drill of FIG. 1 as viewed from a distal end side.
FIG. 3 is a sectional view taken along the line AA of FIG. 1;
FIG. 4 is a side view of the throw-away tip.
FIG. 5 is a view of the throw-away tip as viewed from the distal end side.
FIG. 6 is a side view of the throw-away tip.
FIG. 7 is a diagram for explaining a gap.
FIG. 8 is a view showing a problem of a conventional drill.
[Explanation of symbols]
1 ... drill body, 2 ... tip (throwaway tip), 2b ... outer surface,
2d ... (exposed) surface, 3 ... tip surface, 6 ... concave groove, 6b ... inner surface, 7 ... guide groove,
13: convex portion, 21: first margin portion, 22: second margin portion, 23: groove portion,
O: axis, D: drill

Claims (3)

In a drill having a drill body rotatable around an axis and a detachable tip that is detachable from the drill body,
The indexable tip is formed in a substantially flat plate shape,
The drill body has a concave groove portion at the tip portion where the throw away tip can be arranged,
Surfaces on both sides in the direction intersecting with the axis of the throw away tip arranged in the concave groove portion are set to be exposed from the drill body, respectively.
A drill characterized in that at least two margin portions corresponding to a workpiece are provided on each of the both surfaces of the indexable insert. The concave groove portion is formed along a plane including the axis so as to open to a tip end surface of the drill body, and a guide groove extending in a direction along the axis line is provided on an inner surface of the concave groove portion, and the throw away The drill according to claim 1, wherein a convex portion capable of meshing with the guide groove is provided on an outer surface of the tip facing the inner surface of the concave groove portion. In a substantially flat-shaped throw-away tip that can be inserted into a concave groove portion opened in the tip surface of the drill body,
It is set so that the surfaces on both sides in the direction intersecting with the insertion direction when inserted into the concave groove portion are respectively exposed from the drill body,
A throw-away tip, wherein at least two margin portions corresponding to the workpiece are provided on each of the two side surfaces.

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