JPS5932483Y2 - Throwaway tip - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an indexable tip, particularly an indexable tip in which the tip has a chip disposal function.

In order to efficiently cut the outer diameter and inner diameter of the work material, it is necessary to effectively dispose of chips, and for this purpose,
The indexable tip is provided with various chip disposal mechanisms.

Among these, as shown in FIG. 1, a breaker groove 2 of the same width is formed all around the cutting edge of an indexable insert 1, or as shown in FIG.

It is common to have two breaker grooves that gradually narrow from the nose.

These are designed to curl the chips at a predetermined curvature along the respective grooves 2, 2', and divide the chips appropriately.

However, these chip disposal mechanisms are limited by the cutting edge length l.
It is effective when the depth of cut is 1/3 to 1/2 and the feed is increased, but depending on the cutting method, the entire area of the cutting edge may be used, and in this case, the feed may be relatively small. , the thickness of the chips becomes smaller and they cannot perform their functions.

In other words, when the depth of cut is made small, the chips are curled relatively well under the influence of the nose part even if the thickness is a little small, making them more likely to break. However, when the depth of cut is made large, the chips are not guided well into the breaker groove and break off to a certain curvature. Do not curl.

In the case of the one shown in FIG. 1, the width of the breaker groove is constant, so the chips come into contact with the groove 2 over the entire width direction, thereby dispersing the breaking force.

In addition, the width of the breaker groove 2' in the one shown in Fig. 2 changes, so it is possible to add some curl, but there is almost no difference from the former, and therefore, the chips can be extended without any curl. It has the disadvantage of getting wrapped around the holder, etc.

This also applies when only the central portion of the cutting edge is used, such as in chamfering operations.

In order to overcome the above-mentioned drawbacks, a breaker that can partially distort the chips is required.

Conventionally, devices have been devised in which the chips are partially distorted by small protrusions, etc., but these methods are less effective when the thickness of the chips is small.

This invention was proposed in order to eliminate the above-mentioned drawbacks, and provides an indexable insert that is thin, has a wide width that can be scooped into the center of the cutting edge, and can effectively process small chips. It is intended to.

The configuration of this invention will be explained below based on the attached drawings.

Note that this invention is applicable not only to the one shown in the figure but also to equilateral triangular and rhomboid shaped chips, but for convenience of explanation, only a square chip is shown here.

As shown in FIGS. 3 to 7, the indexable tip 10 of this invention has a flat upper surface 11 that serves as a rake surface.
and a lower surface 12 that is almost parallel to this.

A truncated conical protrusion 14 serving as a breaker is provided on the upper surface 11 of the negative type indexable tip, which is composed of a side surface 13 that intersects at right angles with the upper surface 11.

A plurality of small projections 15 are formed.

The protruding part 14 is a gamma-shaped piece whose center is set concentrically with the inscribed circle of the cutting blade 16, and its diameter d is made 0.5 to 3 smaller than the diameter of the inscribed circle, and , the height H to the upper end is increased by 0.1 to 1 from the cutting edge 16.

This protrusion 14 has a cutting edge 16 at the center of the chip 1.
closest to.

Therefore, as shown in FIG. 7, the distance C from the cutting edge 16 to the protrusion 14 becomes minimum at the center of the cutting edge and gradually increases toward both sides.

The reason why the diameter and height of the protrusion 14 are limited to the above values is that if it is too close to the cutting edge or too high, it will easily interfere with chip evacuation. This is because if the force (force) or H is less than 0.1 maN, there is a risk that the chips will not make good contact.

Further, if only the protrusions 14 are formed on the rake face, the distance from each nose 17 to the protrusions 14 becomes long, which causes problems in cutting using the noses.

Therefore, small protrusions 15 are formed on the upper surface 11 close to each nose 17.

This small protrusion has a truncated conical shape and is formed at approximately the same height as the protrusion 14, and can effectively distort chips starting from the nose portion.

In addition, the shape of the small protrusion 15 may be spherical, as shown in FIG.

Further, the shape of the chip to which this invention is applied is not limited to the illustrated negative type, but may be a positive type.

Furthermore, since the negative type includes a double-sided type, in that case, the protrusions 14 and small protrusions 15 may be formed on both sides of the chip.

The throw-away tip of this invention has the above configuration,
When cutting with this, even small chips come into sufficient contact with the protrusions or small protrusions, making them easier to curl.

Also, since only a portion of the chips come into contact with each other, in chamfering work where the straight section of the cutting edge is used over a wide area, as shown in FIG. The distance of straight movement is P<P', and the magnitude of the strain applied to the chips is P>y, so that the chips are given an ideal breaking force and are reliably separated.

As mentioned above, the indexable insert of this invention is extremely effective not only for normal chips but also for cutting with large depth of cut and chamfering work, etc. Also, since the area of the upper part of the protrusion is large, it can be used on both sides. The supporting state when molded is also stable.

[Brief explanation of the drawing]

FIG. 1a is a plan view showing a conventional indexable tip, FIG.
Figure a is a plan view showing another conventional indexable tip, Figure 2 is an enlarged sectional view taken along the line ■-■ as above, and Figure 3
The figure is a plan view showing the indexable tip of this invention.
Figure 4 is a side view of the same as above, Figure 5 is a perspective view of the same, Figure 6 is an enlarged sectional view taken along line 1-1 in Figure 3, and Figure 7 is an enlarged view taken along line IV-IV of Figure 3. FIG. 8 is a cross-sectional view showing a main part of another embodiment, and FIG. 9 is a view showing a state in which chips are discharged during chamfering work. 10... Throwaway tip, 11...
...Top surface. 12...Bottom surface, 13...Side surface, 14.
...protrusion. 15... Small protrusion, 16... Cutting edge, 17
...Tooz.

Claims (1)

[Scope of utility model registration request] In a polygonal indexable insert having a flat rake or cutting edge portion (b) and a rake face inclined toward the center, there is a surface on the rake face 0.
A truncated conical protrusion that is 5 to 3 mm smaller and 0.1 to 1 higher than the cutting edge is formed, and a spherical or truncated conical protrusion that is approximately the same height as the protrusion is formed near each nose. A throw-away tip characterized by forming a small protrusion.