JPS6339706A - Throw away type boring tool - Google Patents

Abstract

PURPOSE:To improve the tool rigidity by eccentrically fitting a tip provided with a slant face on the upper square portion to the tip section of a tool main body and securing a large back metal on the tool main body side. CONSTITUTION:A diamond-shaped tip 10 formed with a slant face 12 is removably fitted to the tip seat 3 of a tool main body 1 with a clamp screw 6. A negative rake angle alpha is applied so that the axis O of the tool main body 1 is located on a cutting blade 13 inclined by the slant face 12 or on the slant face 12 side apart from the cutting blade 13. Therefore, this tip 10 is fitted eccentrically by a size (a) from the axis O to the upper face 11. The axis O of a drill is made to match the rotary axis of a work, and boring machining is performed. This drill can secure a back metal with a large size L1 on the tool main body 1 side, thus the high tool rigidity can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a throw-away type hole-drilling tool suitable for use in various hole-drilling operations such as drills and poling tools.

[Prior Art] Figures 16 and 17 show a conventional indexable drill, in which the above-mentioned indexable drill is a type of tool, so the reference numeral 1 in the figures is the drill body (tool body). .

This drill body l has a generally circular shape in appearance, and a chip discharge 1112 is formed along the axial direction on the outer periphery of its tip, and a chip seat is formed on the wall surface facing the rotation direction of the tip of this chip discharge groove 2. 3 is formed. A rhombic plate-shaped indexable tip (hereinafter referred to as a tip) 4 made of cemented carbide or the like is placed on the tip seat 3 at its ridgeline to cut a cutting edge 5 toward the tip of the drill body 1. It is removably mounted with a clamp screw 6 at the position shown in FIG.

Here, this depth 4 has its cutting edge 5 positioned along the radial direction from the axis O of the drill body l, and its axis O.
It is mounted with the upper end 5a located closer to the tip of the drill body l than the outer peripheral end 5b.

In the conventional indexable drill having the above configuration, when either the trill or the workpiece is rotated, the cutting blade 5 is sent in the zero direction of the axis. A hole with a radius equal to the entire length of the cutting blade 5 is machined in the workpiece.

[Problems to be Solved by the Invention] However, in the conventional indexable drill described above, when the end 5a of the cutting edge 5 is positioned beyond the axis 0 of the drill body I, the tip of the drill body L The portion extending beyond the axis O that protrudes to the side rubs the surface of the workpiece, making it impossible to drill holes. Furthermore, if the end portion 5a does not reach the axis O, a cylindrical core that is not cut between these ends will be formed in the workpiece.

Therefore, the cutting edge 5 has one end 5a aligned with the axis 0.
It must be located along the radial direction of the drill body 1. For this reason, as shown in Fig. 17, it is not only possible to increase the thickness of the tip 4, but also it is not possible to provide sufficient back metal r7 for the trill body I, resulting in poor tool rigidity. There was a problem.

In addition, since the inner diameter of the hole that can be machined with the - drill is only one, it is necessary to prepare drills with different tip sizes for the number of inner diameters of the holes to be machined, which is extremely uneconomical. there were.

[Object of the invention] This invention has been made in view of the above circumstances, and an object thereof is to provide a throw-away type drilling tool that can have a large back metal on the tool body side and has excellent tool rigidity. It is something.

[Means for Solving the Problems] The throw-away type hole drill of the present invention has a tool that has a corner portion located on the center side of the tool body on the top surface, and a corner portion located on the center side of the tool body on the top surface. A chip with an inclined surface in which the thickness between the upper and lower surfaces gradually becomes thinner toward the tip side is placed on the cutting edge where the axis of the hole to be machined is inclined along the above-mentioned inclined surface, or from this cutting edge to the above-mentioned inclined surface. It is attached so that it is located on the side.

[Example] Figures 1 to 5 show an example in which the indexable drill according to the present invention is applied to an indexable drill as a first embodiment of the tool. Parts common to those shown are given the same reference numerals.

In FIGS. 1 to 5, in the indexable drill of this example, a diamond-shaped plate-shaped tip IO is detachably attached to a depth seat 3 of a drill body (tool body) by a clamp screw 6.

This chip! 0 is an inclined surface 12 in which a corner portion of the upper surface 11 located on the axis 0 side of the drill body 1 has a thickness gradually thinner between the upper and lower surfaces from the center of the upper surface 11 toward the tip end of the corner.
is formed by.

Therefore, this top surface II drill body! The cutting edge 13 formed on the ridgeline on the tip side is formed to be inclined from the upper surface II toward the lower surface side at the corner portion.

As shown in FIG. 4, this tip 10 has a cutting edge I3 whose axis O of the drill body l is inclined by an inclined surface I2.
It is mounted so as to be located above or on the side of the inclined surface 12 from the cutting edge 13, with a negative rake angle α. Therefore, this chip IO is mounted upwardly by the dimension a from the axis 0 to the upper surface It. In addition, the symbol in the figure! 4 is the cutting edge 1 from the base end of the drill body l.
3 shows a side hole for supplying cutting oil to the vicinity.

Next, the operation of the above-mentioned indexable drill having the above-mentioned configuration will be described in the case where drilling is performed by rotating the workpiece side.

First, the axis 0 of the indexable drill is aligned with the rotational axis of the workpiece, and the indexable drill is placed toward the workpiece in the direction of its axis O. Then, the axis of the indexable drill is 0 on the workpiece.
A hole is machined with a radius equal to the dimension from the end 13b of the cutting blade 13 to the end 13b of the cutting blade 13.

In this case, as shown in FIG. 5, as a result of forming the inclined surface I2 at the corner portion of the tip 10, the portion of the cutting edge 13 that is inclined by the above-mentioned inclined surface 12 or the straight portion along the upper surface 11 is Since the trill main body 1 is inclined at an angle θ from the outer circumferential side to the center side toward the live wire portion of the trill main body 1, the portion of the center side end 13a that exceeds the axis O comes into contact with the workpiece. Never.

Additionally, this indexable drill can also be used to drill holes with different inner diameters.

That is, as shown in FIG. 6, the axis O of the indexable drill is separated from the rotational axis 01 of the workpiece by a predetermined distance X, and the drill is sent in the direction of the axis O. Then, the workpiece is machined by two people, whose radius is the dimension from the axis of rotation 01 to the end 13b of the cutting blade I3. therefore,
The above-mentioned mutual axes 0.0. A hole will be machined whose inner diameter is larger by the dimension 2X than the hole that would be machined if the numbers were matched. During machining, this hole drilling is performed from the rotation axis 0 of the workpiece, and from this axis 0 in the vicinity to the cutting edge 13.
15 small cylindrical cores with a radius equal to the distance between them are formed. The core 15 grows in accordance with the feed of the indexable drill, and then comes into contact with the inclined surface 12 of the tip 10 and is cut.

As described above, in the throw-away type trill of this example, since the inclined surface 12 is formed at the corner portion of the upper surface 11 of the chip 10, the chip IO can be mounted higher than the conventional trill. Therefore, it is possible to secure a back metal having a large dimension L1 on the drill body 1 side, so that high tool rigidity can be obtained.

Moreover, as a result of forming the inclined surface I2, the inclined portion of the cutting edge 13 becomes the drill body! Because the cutting edge 1 is inclined toward the proximal end of
The center side end 13a of No. 3 can be extended to a position beyond the axis 0, and therefore, as mentioned above, an excellent effect can be obtained in that holes with different inner diameters can be drilled with a - drill. . Further, the hole at one end can be drilled by so-called fine poling, etc., by slightly displacing the axis O from the rotation axis OI of the workpiece to expose the inner diameter of the hole again after machining.

Embodiment of Meya] FIGS. 7 to 1+ show an indexable drill which is a second embodiment of the indexable drilling tool of the present invention.

In the indexable drill of this example, the top surface 21 of the tip 20 attached to the trill main body 1 has a thickness fr from the center of the top surface 21 to a corner portion on the center side, and a thickness between the top and bottom surfaces toward the bottom side. An inclined surface 22 is formed which gradually becomes thinner, and a stepped portion 23 substantially parallel to the upper surface 21 is formed between this inclined surface 22 and the tip of the corner. Similar inclined surfaces 22 and stepped portions 23 are also formed at corners diagonally opposite this corner.

The tip 20 is also provided with a negative rake angle α so that the axis O of the drill body 1 is located on the cutting edge 24 inclined by the inclined surface 22 or on the inclined surface 22 side of the cutting edge 24. is installed.

As a result, in the throw-away type trill of this example, as shown in FIG. By spacing a predetermined dimension X from
Holes with different inner diameters can be machined.

Therefore, even in the indexable drill mentioned above,
In addition to being able to obtain the same effects as those shown in the first embodiment, this indexable drill also has a stepped portion 2 between the inclined surface 22 and the tip of the corner.
3, so the tip 2 at the tip of this corner
Since it is possible to prevent a decrease in the strength of the core and also to increase the angle of inclination of the inclined surface 22, it is possible to obtain the effect of excellent cutting performance of the core.

In addition, since the inclined surfaces 22 and the step portions 23 are formed symmetrically at the diagonally opposite corner portions of the chip 20, by rotating the chip 20 by 180”, the portions become even more symmetrical. Hole drilling can be performed using the , so you can benefit from its Bi-resistance properties.

In addition, in the description of the first and second embodiments above, when machining holes with different inner diameters, the cutting edge 13.24
and the above rotation axis 0. The axis 0 is spaced apart from the rotation axis aO1 of the workpiece so that a gap is created between the core and the core, but the invention is not limited to this. By spacing the axis 0 along the end 13a of the cutting blade 13, the hole can be drilled without forming a core.

Further, as shown in FIG. 13, a slope 26 that is gentler than the slope 22 is formed between the slope 22 and the tip of the corner, and the axis 0 is spaced apart along the sloped cutting edge 24a of this part. You may let them.

Also, the shape of the chip used for one neck is not limited to a diamond shape.
4 < , as in the example shown in FIGS. 14 and 15,
A trapezoidal tip 30 has an inclined surface 32 formed at a corner portion of an upper surface 31 located toward the center of the drill body I, in which the thickness between the upper and lower surfaces gradually decreases from the center toward the tip of the corner. You may also wear something.

[Effects of the Invention] As explained above, the slow 79584 type drilling tool of the present invention has a tool that has a hole at the tip of the tool body, and a corner portion located on the center side of the tool body on the upper surface. A chip with an inclined surface that gradually thins the thickness between the upper and lower surfaces toward It was installed to do so.

Therefore, according to the indexable type drilling tool, since the tip can be mounted upright, a large back metal can be secured on the tool body side, and as a result, high tool rigidity can be obtained. Moreover, as a result of extending the cutting edge to a position beyond the axis, by separating the axis from the axis of the hole to be machined, holes with different inner diameters can be machined with one tool.

Furthermore, after machining one end hole, by slightly moving the axis from the rotational axis of the workpiece and exposing the inner diameter of the hole again, so-called fine polling can be performed. can be obtained from

[Brief explanation of drawings]

Figures 1 to 5 show a first embodiment of the indexable hole drilling tool of the present invention, with Figure 1 being a plan view, Figure 2 being a front view, and Figure 3 being a proximal side view. 4 is a side view of the tip side, FIG. 5 is an enlarged plan view of the tip, FIG. 6 is a diagram showing an example of machining in which the holes are drilled using a tool, and FIGS. 7 to 1θ. The figures show a second embodiment of the present invention; FIG. 7 is a plan view, FIG. 8 is a front view, FIG. 9 is a side view of the tip end, and FIG. 11 is a diagram showing an example of machining in which the hole is drilled using a tool, and FIGS. 12 and 13 are diagrams each showing an example of mounting other chips.
4 and 15 show a third embodiment of the present invention, FIG. 14 is a plan view, FIG. 15 is a view taken along line B-B of FIG. 14, and FIGS. 16 and 17 are a conventional Fig. 16 is a plan view of the tip, Fig. 17 is a top view of the indexable drill.
The figure is a side view of the tip side. I...Drill body (tool body), 3rd...Chip seat, 10.20.30...Throwaway depth, 11.21.31...Top surface, 12.22 .26.32... Slope, 13.2
4... Cutting edge, 0.01... Axis line.

Claims (1)

[Scope of Claims] A throw-away type drilling tool in which a throw-away tip is attached to the tip of a tool body with a cutting edge formed on a ridgeline on the upper surface thereof positioned on the tip side of the tool body. , forming an inclined surface on a corner portion of the upper surface of the throw-away tip located on the center side of the tool body, the thickness between the upper and lower surfaces gradually becoming thinner from the center of the upper surface toward the tip of the corner portion; Further, the throw-away tip is mounted such that the axis of the hole to be machined is located on the cutting blade that slopes along the slope, or on the side of the slope from the cutting blade. Type drilling tool.