JPH0426167Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a throw-away tip that is used by being attached to a cutting tool, and particularly relates to a throw-away tip that is suitable for thread cutting and has improved disposal of cutting waste. .

(Prior art) In thread cutting, as in other cutting processes, it is preferable to break the cutting waste into small pieces so that the cutting waste does not get wrapped around the tool or the workpiece, but the depth of cut is extremely small. It is extremely difficult to break the chips under cutting conditions where the feed rate is high, and if you try to forcefully break the chips with a chip breaker, etc., the cutting resistance will increase, and if the material is not rigid, it will cause so-called chattering. Abnormal vibrations called so-called abnormal vibrations occurred and machining accuracy decreased.

For this reason, conventional throw-away tips for thread cutting either do not form a tip breaker or
As shown in FIG. 5, a tool in which a groove 53 is formed near the cutting edge 52 to partition the cutting edge 52 from the main body side has been used. However, these throw-away tips 51 break the cutting waste into small pieces,
It is not possible to control the ejection direction or stabilize the entrainment of cutting chips, and there is a problem in that long cutting chips wind around tools, objects to be cut, and the like.

Therefore, in order to solve these problems, a throw-away tip for thread cutting was developed in which a recess was formed on the rake face and the cutting waste was smoothly discharged. No. 62-106694.

(Problem to be solved by the invention) However, in the former case, since the recess is provided at a distance behind the cutting blade, there remains a problem in controlling the delivery of cutting chips from the cutting blade to the recess.
In addition, in the latter case, since the recess is formed near the cutting edge, the cutting chips are sent smoothly into the recess, but there is a problem in winding them into a stable string-wound shape (regular curl shape). was what remained.

The present invention is a throw-away tip for thread cutting that solves the above problems, smoothly sends the cutting waste generated during thread cutting into the recess, and stably discharges the cutting waste in a string-wound shape. We aim to provide the following.

(Means for Solving the Problems) In order to achieve the above object, the present invention is a throw-away tip for thread cutting, which has a cutting edge corresponding to the shape of a thread groove at a corner portion, and has a cutting edge inside the cutting edge. The upper surface part is a delivery groove recessed than the cutting edge, and a winding recess which is deeper than the delivery groove and has a side opening by notching the upper part of at least one side of the throwaway chip is provided inside the delivery groove. A thread-cutting throw-away tip is continuously formed near one side of the thread-cutting tip.

In this case, the side opening is provided on the thread cutting direction side (front side in the advancing direction) of the throw-away tip, and the concave bottom of the winding recess is located on the advancing direction side than the bisector of the cutting edge. It is preferable that it is formed.

(Function) According to the throw-away tip for thread cutting, the cutting waste generated by the cutting blade is guided by the delivery groove and delivered to the winding recess, and is continuously curled in the winding recess. Since the winding recess is open on one side, the cutting waste is wound up in a string-wound shape and discharged from the side opening, and the cutting waste is guided to the bottom of the recess.

(Example) Hereinafter, an example of the throw-away tip for thread cutting according to the present invention will be described with reference to the drawings.

1 to 4 show an embodiment of the throw-away tip for thread cutting, in which FIG. 1 is a perspective view thereof, FIG. 2 is a partially enlarged plan view showing the cutting blade portion, and FIG. The figure is a side view thereof, and FIG. 4 is a schematic plan view schematically showing the flow of cutting waste during use.

A throw-away tip for thread cutting (hereinafter referred to as a tip) 1 is a thick plate in a roughly triangular shape made of cemented carbide, cermet, ceramic, etc., and has tip support surfaces 2 on both upper and lower surfaces. An insertion hole 3 for attaching a cutting device is formed in the center thereof, and a cutting edge 5 adapted to the shape of a thread groove is formed on the outer peripheral edge of each corner portion 4.
The side surface is a flank surface 6 having a cross section substantially the same as that of the cutting edge 5.
The upper surface of the cutting edge 5 slopes downward inward, and leaves a narrow land 7 along the cutting edge 5, with a slight depth (for example, 0.05~
A cutting waste delivery groove 8 having a diameter of 0.5 mm) and sloping downward in the direction of a winding recess 9, which will be described later, is formed. A concave part 9 for trapping cutting chips having a mortar-like upwardly expanding curved surface deeper than the above is formed by partially notching the upper part of the side surface of the chip on the threading direction side, and the notch part is formed by a side opening. It is designated as part 10. The winding recess 9 has a recess bottom 9a formed on the traveling direction side of the bisector (imaginary line) X of the cutting edge 5, and a peripheral surface within the recess slopes downward toward the recess bottom It is formed as a surface.

Further, the outer peripheral edge of the side surface opposite to the side surface opening 10 across the cutting edge 5 is bent from the cutting edge 5 to form an edge 11 or an edge 11 in a direction perpendicular to the bisector X of the cutting edge 5. It is formed as an edge inward of the orthogonal edges, and the inner side of the edge is a recessed portion 11a with a portion of the upper portion of the opposite side cut out.

Then, the tip 1 is fixed to the insertion part of the throw-away tool by inserting a bolt or the like into the insertion hole 3, and the throw-away tool is inserted into a cutting device and a suitable tool such as a round bar or the like is inserted into the cutting device. When the cutting blade 5 is pressed against the workpiece 20 and fed in the thread cutting direction at a predetermined speed, a thread groove is formed in the workpiece 20 by the cutting blade 5 as shown in FIG. At the same time, cutting debris 21 is generated in the area. The cutting debris 21 generated by the cutting edge 5 climbs over the land 7 and enters the delivery groove 8.
While being guided by the delivery groove 8, it is pushed away by the following cutting waste 21 and moved to the winding recess 9. Furthermore, the cutting waste 21 hits the inclined wall surface of the winding recess 9, is rolled up while continuously curling upward, and is formed into a string-wound wire shape from the side opening 10 provided on the side surface of the chip 1. The chip 1 is then discharged in the threading direction. At this time, the concave bottom 9a
is formed on the advancing direction side of the bisector of the cutting edge 5, so that the cutting chips are stably discharged in the advancing direction, and there is no risk of them wrapping around or coming into contact with the machined part. be excluded.

Note that the edge 11 may be used as a cutting edge or may not be used as a cutting edge. Whether or not to remove the threaded portion can be selected depending on the precision of the screw, surface roughness, etc. If the thread is used as a blade, the edge 11 should be removed in a direction perpendicular to the bisect of the cutting edge 5 as described above. It can be used if it is formed.

In the above, the tip is not limited to a substantially triangular plate, but can be applied to various polygonal plates, and the cutting edge shape can also be manufactured to correspond to various thread groove shapes. can. Furthermore, it may have a clamp configuration in which the insertion hole 3 is not provided and it is fixed from the top, or it is also possible to provide the same configuration as the above-mentioned upper surface on both the upper and lower surfaces and use both surfaces.

(Effects of the invention) As described above, according to the throw-away tip for thread cutting of the present invention, the cutting waste generated during thread cutting is sent out through the delivery groove to the winding recess. At the same time, the cutting waste is continuously curled upward in the winding recess and rolled up, and is discharged from the side opening in a string-wound shape. Therefore, the cutting waste does not get wrapped around the tool or the workpiece, and the processing efficiency of the cutting waste can be improved, and production efficiency can be increased.

In addition, if an opening for the winding recess is formed on the side surface in the thread cutting direction, the cutting waste will be rolled up in a spiral shape from the opening in the direction in which the chip advances, and will be discharged from the thread. Since it does not come into contact with cut parts, it does not damage the parts, and it is possible to efficiently produce high-quality screws, bolts, and other items that require threads. These production costs can be reduced.

The above effect is more reliably stabilized by forming the concave bottom of the winding concave portion to be located on the advancing direction side with respect to the bisector of the cutting blade.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the throw-away tip for thread cutting according to the present invention, Fig. 2 is a partially enlarged plan view showing the cutting blade portion, Fig. 3 is a side view thereof, and Fig. 4 is FIG. 5 is a schematic plan view schematically showing the flow of cutting waste during use, and FIG. 5 is a plan view showing a conventional example. 1... Throwaway tip for thread cutting, 4...
... Corner part, 5 ... Cutting edge, 8 ... Delivery groove, 9 ...
...Recess for winding, 10... Side opening.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A throw-away tip for thread cutting having a cutting edge corresponding to the shape of a thread groove at a corner portion, the upper surface portion of which is inside the cutting edge being recessed than the cutting edge. A recess for winding is formed continuously near one side inside the throw-away groove, and the throw-away chip has a recess deeper than the throw-away groove and has a side opening by notching the upper part of one side of the throw-away chip. Throw-away tip for thread cutting. (2) The throw-away tip for thread cutting according to item 1, wherein the side opening is provided on the thread-cutting direction side of the throw-away tip. (3) The throw-away tip for thread cutting according to item 1 or 2, wherein the bottom of the winding recess is located on the advancing direction side of the bisector of the cutting blade.