JPH0569206A - Throwaway cutting tool - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a chip with high chip disposability and a long life, and a throw-away bite capable of stably supporting such a chip. [Structure] The positive-type throw-away tip 6 has chamfer honing with a honing width of 1 mm or more and a honing angle of 2 to 15 degrees on the cutting edge portion formed on the ridges of the upper and lower rake surfaces, and the tip receiving seat 26 is received. Formed on the surface is a protrusion that fits into the honing portion on the lower surface of the chip 6. Then, insert the chip 6 into the throwaway bite base 3
6 is mounted via the seat 26, and is clamped and fixed from above by a clamp piece 50 via a chip breaker 48.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw away tool used for cutting metal materials and the like.

[0002]

2. Description of the Related Art If a cutting edge of a throw-away tip (hereinafter referred to as "chip") is sharp, the cutting edge is likely to be damaged during cutting. Therefore, conventionally, the cutting edge is flat or curved (honed). ) Is being done. FIG. 7 shows an example of honing of the cutting edge of the chip. (A) shows a cutting edge formed on the ridge line between the rake face 2 and the flank face 4 in a plane shape with a honing width L and a honing angle θ. In the case of chamfer honing (negative land), (b) is a case where the cutting edge formed on the ridge portion of the rake face 2 and the flank face 4 is notched in a curved shape with a radius R (= honing width M) and is round honed. Is. Honing is generally performed with honing widths L and M of about 0.05 to 0.5 mm and a honing angle θ of about 15 to 25 degrees.

[0003]

In the above-mentioned conventional honing tip, the chips cut by the cutting edge pass through the rake face of the tip while rubbing during cutting. For this reason, in the above chips, the heat generated by the wear of the chips and the rake face tends to reduce the high temperature strength of the material, and the wear tends to shorten the life. The present invention is based on the technical background as described above,
An object of the present invention is to provide a chip having a high chip disposal property and a long life, and also to provide a throw-away bite capable of stably supporting such a chip.

[0004]

SUMMARY OF THE INVENTION According to the present invention, in a throw-away bite equipped with a mechanism for clamping and fixing a tip to a base body via a sheet, the tip is provided with a cutting edge portion at the ridges of the upper and lower rake faces. And a chamfer honing with a honing angle L of 2 to 15 degrees is performed on each of the cutting edge portions formed on the ridge, and the chafer honing of the sheet is performed. The tip receiving surface is formed with a protrusion that fits into the honing portion of the tip.

[0005]

In the throw-away bite having the above structure, since the honing width L is 1 mm or more in the chamfer honing of the cutting edge of the tip, the honing width L becomes a value larger than the tool feed amount and the work material is cut. It is cut by the honing part of the blade. And the honing angle θ
Since the angle is 2 to 15 degrees, the chips pass through the honing surface, are then pushed out in a direction substantially parallel to the honing surface, and are broken by the bending action. A cutting resistance is applied to the chip during cutting, but this force is received by the sheet laid on the lower surface of the chip, and the cutting is performed stably.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First, with reference to FIG. 3, a chip used in the throw-away byte according to the present embodiment will be described. This figure shows a negative type chip 6 having a substantially square shape in plan view.
Is shown. In the upper half surface of the tip 6, four cutting edge portions 12 extending rightward from the corner portion are formed at the ridges of the upper rake face 8 and the four flank faces 10. The cutting edge portion 12 is formed by honing (chamfer honing) the corner portion of the tip 6 into a substantially rectangular shape in a plan view, and the honing width L is 1 to 5 mm larger than the normal tool feed amount, and , Its honing angle θ
Is set in the range of 2 to 15 degrees. The ridge line portion 16 between the honing surface 14 and the rake surface 8 is provided with a minute round honing with a radius R of 0.1 mm. Chip 6
The lower half surface is formed in point symmetry with the upper half surface of the above-mentioned tip 6 with the center of the tip 6 as a point of symmetry, and the ridge line portion between the lower rake surface 20 and the four flanks 10 ... Four cutting edge portions 22 ... Which extend rightward from the corner portion are formed.

Next, the sheet used for the throw-away bite according to the embodiment will be described with reference to FIG. This figure shows a sheet 26 having a substantially square shape in a plan view, and an upper surface (chip receiving surface) 28 of the sheet 26 is formed with projections 30 that are fitted to the rake surface 8 or 20 of the chip 6. Has been done. That is, on the upper surface 28, four protrusions 30 ... Leftwardly extending from the corners are formed. The inclination angle ψ of the protrusions 30 is formed to be the same as the honing angle θ of the tip 6, and the protrusions 30 are formed. The part 30 is adapted to fit into the cutting edge part 12 or 22. The lower surface 32 of the seat 26 is a flat surface. Also, sheet 2
A screw hole 34 is formed in the central portion of 6 to penetrate from the upper surface 28 to the lower surface 32.

Next, with reference to FIGS. 1 and 2, the attachment of the throw-away bite of the tip 6 to the base will be described. In these drawings, reference numeral 36 denotes a throw-away bite base body (holder), and a seat seating surface 40 having a screw hole 38 formed in the center and one end portion of a clamp screw 42 are screwed into the tip end portion thereof. A screw hole 44 for forming is formed. When mounting the chip 6 on the base 36, the seat 26 is fixed to the seat seating surface 40 by the seat pins 46, and then the chip 6 and the chip breaker 48 are laminated on the seat 26. On the other hand, one end of the clamp screw 42 is screwed into the screw hole 44 and the other end is screwed into the clamp piece 50. Then, the tip end 52 of the clamp piece 50 presses the upper surface of the chip breaker 48 downward to clamp and fix the chip 6 to the base 36 (see FIG. 1).

When the chip 6 is fixed to the cutting tool as described above and the work is cut, the honing width L is set to be sufficiently larger than the tool cutting amount k as shown in FIG. The cutting material is the honing surface 1 near the ridge 18.
Cut at 4. Then, the chips are extruded along the honing surface 14 in a direction substantially parallel to the honing surface 14, guided in a direction away from the rake surface, and divided by a bending action. At this time, since the cutting resistance in the chip discharge direction is reduced, the temperature rise of the chip due to rake face wear is suppressed and the wear resistance is improved, the chip disposability is improved, and the life of the chip 6 is extended. Since cutting resistance is applied to the tip 6 during cutting, if the tip receiving surface 28 of the sheet 26 is a flat surface, the tip 6 will be attached to the tip 6 by the gap between the honing portion on the lower surface side of the tip 6 and the tip receiving surface 28 of the sheet 26. Although vibration will occur, the tip receiving surface 28 of the sheet 26 is formed with the projections 30 ... Which are fitted to the rake surface 8 or 20 of the tip 6 as described above, and therefore is shown in FIG. As shown in FIG.
It is supported in close contact with the chip receiving surface 28 of the above. Therefore, the tip 6 does not vibrate due to the cutting resistance, and the cutting is stably performed.

The honing angle θ is set in the range of 2 to 15 degrees. This is because if the angle θ is less than 2 degrees, the life of the tip is not extended, and if the angle θ is 15 degrees or more, the cutting resistance is increased. Is too large, the wear of the cutting edge increases, and the life of the tip is shortened in each case. FIG. 6 shows a chip in which a cemented carbide is coated with titanium carbide, titanium nitride and aluminum oxide, and chamfer honing (circular honing) is performed under each condition.
It shows the relationship between the cutting time (horizontal axis) and the amount of wear of the flank (vertical axis) when 15 was cut at high speed. The honing conditions were a honing width L of all 3 mm, a honing angle θ of 0 degree (when round honing with a radius R of 0.1 mm), 5 degrees, 10 degrees, and 15 degrees. The cutting speed was 630 (m / min), the depth of cut was 1.0 mm, and the feed rate was 0.25 (mm / rev). In the figure, P1 is radius 0.
In the case of 1mm round honing, P2 is when θ is 5 degrees,
P3 shows the case where θ is 10 degrees, and P4 shows the case where θ is 15 degrees. From the figure, it can be seen that the wear amount decreases in the order of P3, P2, P4, and P1 in the state where the cutting time is 2 minutes or more.

Further, in order to see the effect of the throw-away bite according to the present invention on the unstable phenomenon of cutting, a high feed cutting test was conducted under the following conditions. The results are shown in Table 1. The present invention uses a throw-away bite similar to that shown in FIGS. 1 and 2 described above, and five types of chips in which the land angle and the land width are changed to various values and the lower surface of these chips are fitted. A sheet having an upper surface formed in a shape to be used was used. Further, as comparative products 6 to 8, the same chips as those of the products 1 to 3 of the present invention were mounted on a chip holder similar to the chip holder of FIGS. 1 and 2 using a plate-shaped sheet having a flat upper surface. The comparative product 9 is a conventional shaped honed chip with a small land width, and a conventional plate-shaped sheet is mounted on the same chip holder as the comparative products 6 to 8. Using. In Table 1, the contact method indicates a contact state between the chip and the sheet.

Work Material: SCM415 Round Bar with 4 Grooves of 10 mm Width Cutting Speed: 200 m / min Feed: 0.9 mm / rev Cutting Depth: 1.5 mm Cutting Time: 25 Minutes

[0013]

[Table 1]

As can be seen from Table 1, the throw-away bite according to the present invention, in which the projection for fitting with the chip is formed on the upper surface of the seat, does not cause chatter vibration during cutting and can be used for a long time. It can be seen that stable cutting is possible.

In the above embodiment, only the ridge line portion 16 is round-honed, but in order to further improve the fracture resistance of the cutting edge, a minute round honing is also applied to the horn line portion 18 and the ridge line portion 18 of the flank 10. It is preferable to apply. Also, honing is not round honing, honing width L is 0.1 m
It may be chamfer honing of about m.

The chamfer honing of the chip 6 described above is not limited to the construction by grinding, but may be molding.

[0017]

As described above, according to the present invention, since the cutting edge of the tip is chamfered with a honing width L of 1 mm or more and a honing angle θ of 2 to 15 degrees, chip disposability is improved. Is improved and the chip life is extended. This tip is supported by the throw-away bite through the sheet having the tip receiving surface formed with the protrusion that fits into the honing portion of the tip, so that the tip is stably supported by the throw-away bite. Therefore, good cutting is possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a tip-mounted state of a throw-away bite according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the throw-away bite.

3A and 3B show a chip according to the embodiment, FIG. 3A is a plan view, FIG. 3B is a front view, and FIG. 3C is a side view.

FIG. 4 is a view showing a seat according to the embodiment, (a) is a plan view, (b) is a front view, and (c) is a side view.

FIG. 5 is an explanatory sectional view showing a cutting state of a cutting edge portion of a chip.

FIG. 6 is a graph showing the relationship between cutting time and flank wear.

FIG. 7 is a partial cross-sectional view showing an example of honing of the tip of the tip.

[Explanation of symbols]

 6 chip 8 rake face 12 cutting edge part 20 rake face 22 cutting edge part 26 sheet 28 chip receiving surface 30 protrusion part 36 base body

Claims (1)

[Claims] 1. A throw-away tool provided with a mechanism for fastening a throw-away tip to a base body via a sheet, wherein the throw-away tip is a negative type in which cutting edges are formed on the ridges of the upper and lower rake faces. The throw-away tip of No. 1 and each cutting edge formed on the ridge has a honing width L of 1 mm or more and a honing angle θ of 2
A throw-away bite, wherein chamfer honing is performed at an angle of up to 15 degrees, and a projection portion that fits into a honing portion of the throw-away tip is formed on the tip receiving surface of the sheet.