JPS624402Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a throw-away cutting tip.

FIGS. 1A to 1E show a conventional throw-away cutting tip (hereinafter simply referred to as a cutting tip) and an example of its cutting process. First, FIG. 1a shows a plan view of a parting tip 1, in which a back taper τ is formed from the cutting edge 2 to the rear edge of the tip. This is to prevent any part other than the cutting edge 2 that performs cutting from coming into contact with the workpiece 3, as shown in FIG. 1b. Moreover, FIG. 1c shows a side view of the parting tip, and a front clearance angle γ _e is provided. Figure 1d is a side view of the state during parting, and shows the front relief angle γ.
Because of _e , nothing other than the cutting edge 2 is in contact with the workpiece 3. Furthermore, FIG. 1e shows a front view of the parting tip, in which a side clearance angle γ _s is provided so that the part other than the corner portion 4 of the cutting edge does not come into contact with the workpiece 3.

By the way, in general, parting-off machining has a deeper depth of cut than grooving, so the entire parting-off tip 1 enters into the workpiece 3, as shown in Figure 1b, and a back taper τ is required. However, for this reason, a normal parting tip can only have one main cutting edge, and there is a problem in that the cost of the tip per cutting edge is relatively high.

Therefore, recently, a triangular chip 6 as shown in FIG. 2 has been provided for the purpose of increasing the number of cutting edges. However, in this case, the corner portion 4 of the cutting blade is often worn and damaged due to parting with the cutting blade 2a, and as a result, the remaining two cutting blades 2b and 2c cannot be used or Even if it can be used, the wear condition of both corner parts 4 of the cutting blade is different, so the surface roughness of the machined surface deteriorates, and the cutting resistance is different in both corner parts 4 of the cutting blade, so the tool holder 5 tends to bend and it is not possible to perform a good cutting process. The problem is that it cannot be done.

The present invention was developed to eliminate the drawbacks of the prior art as described above, and its purpose is to reduce the chip price per cutting edge by providing two cutting edges, and to reduce the chip price per cutting edge by providing two cutting edges. An object of the present invention is to provide a throw-away type parting tip which has independent cutting edge corner parts on each side and can perform good cutting. In order to achieve the above-mentioned object, the present invention provides first and second opposing parts in a throw-away type cut-off tip body having a substantially rectangular parallelepiped shape.
A first cutting knife is provided on a predetermined side of the first surface of the pair of second surfaces, and one side of the second surface is orthogonal to the predetermined side of the second surface. A second cutting knife is provided at the tip, and the first cutting knife and the second cutting knife are each provided with a side clearance angle and a back taper extending from the cutting knife toward the rear edge of the chip.

An embodiment of the present invention will be described below with reference to the drawings. Figures 3a to 3c show the basic shape of the cutting tip according to the present invention, and Figure 3a
3 shows a plan view, FIG. 3b shows a side view, and FIG. 3c shows a front view. In this shape, only the back taper τ is provided, so there are four cutting edges 2, 2', but if the front relief angle γ _e and side relief angle γ _s are provided as described later, the cutting edges will be two. It becomes a place.

Figure 4 shows the basic shape in Figure 3,
A front relief angle γ _e , a side relief angle γ _s , and a recess 7 for stably fixing the main parting tip to the cutting tool holder are provided on the bottom surface on the opposite side of each cutting edge. In this case, one end P of the concave surface has a side relief angle γ _s
The cutting edge should run away from the corner 4 of the cutting edge. As shown in FIG. 4, in the throw-away type parting tip according to the present invention, the first and second parts facing each other in the tip body having a substantially rectangular parallelepiped shape are
A first cutting knife 2 is provided on a predetermined side of the first surface of a pair of surfaces, and a first cutting knife 2 is provided on one side of the second surface that is orthogonal to the predetermined side of the second surface. 2 cutting blades 2 are provided, and if you want to replace the used cutting blade with an unused cutting blade, turn the tip front and back as shown in Figure 5, and rotate it 90 degrees clockwise to use the unused cutting blade. The shape is such that it is possible.

Next, in the parting tip of the present invention constructed as described above, a back taper τ is provided from each cutting edge 2 to the rear edge of the chip, as shown in FIGS. 4a and 4b. Even in the case where the entire parting chip enters the workpiece 3 during parting off of a workpiece with a large diameter as shown in FIG. 2, the side surfaces of the chip other than the cutting edge 2 do not come into contact with the workpiece. Further, since the front relief angle γ _e is provided, no part other than the cutting edge 2 contacts the workpiece 3 even on the front surface of the chip. On the other hand, in the front view shown in FIG. 4c, the side relief angle γ _s is set so that the width is the maximum at the corner 4 of the cutting blade 2.
The parts other than the corner parts 4 do not come into contact with the workpiece 3.

As described above, a first cutting knife is attached to a predetermined side of the first surface of the pair of opposing first and second surfaces of the cutting tip main body having the shape of a substantially rectangular parallelepiped. 2, and a second cutting knife 2 is provided on one side of the second surface that is orthogonal to the predetermined side, and
Since the cutting blade 2 is provided with a front clearance angle γ _e , a side clearance angle γ _s , and a back taper τ extending from the cutting blade 2 toward the rear edge of the chip, it is possible to use either cutting blade. It is possible to carry out a precise parting process, and the cost of the chip per cutting edge can be made extremely low. In addition, as shown in FIG. 4c, the opposite surface of the cutting edge 2 has a concave portion 7, so that it can be stably placed in the tool holder 5, which has a convex portion 8 as shown in FIG. , presser foot 1
The parting tip 1 is firmly fixed to the cutting tool holder 5 by pressing the upper surface of the cutting tip 1 with the bottom surface of the tip of the cutting tip 1 and tightening the presser foot 10 to the cutting tool holder 5 with the tightening bolt 11. .

Note that the present invention is not limited to the above embodiments.

(1) FIG. 5 is a partial perspective view showing the state in which the parting tip 1 of the present invention is attached to the cutting tool holder 5, and a concave chip breaker 9 is provided on the cutting edge 2 of the parting tip 1. This makes it easier to break off chips from parting off, which tend to be long and connected.

(2) Figures 6a and 6b show a plan view and a side view of the parting tip 1 of the present invention provided with a rake face 12 with a positive rake angle d. In addition to reducing cutting resistance, it has the effect of curling chips and making them easier to process.

(3) In addition to the above, the shape of the chip breaker, the contact with the tool holder, and the shape of the restraining portion may be modified without changing the gist of the present invention. Further, the positions of the two cutting edges may be the same as the position of the cutting edge 2' in FIG. 3c, as long as they form an angle of 90 degrees to each other at the edges at both ends of the chip.

As explained above, according to the throw-away type cut-off tip of the present invention, one of the two faces of the pair of opposing first and second faces of the cut-off tip main body having a substantially rectangular parallelepiped shape. A first cutting knife 2 is provided on a predetermined side of the first surface, and a second cutting knife 2 is provided on one side of the second surface that is perpendicular to the predetermined side, and Since the first and second cutting blades are each provided with a side relief angle γ _s and a back taper from the cutting blade toward the rear edge of the chip, compared to conventional parting chips that have only one cutting edge, The chip price per cutting edge is extremely low, and since adjacent cutting edges share the cutting edge corner like a conventional triangular parting chip, wear and tear on one cutting edge will damage the remaining cutting edges. Problems such as the blade becoming difficult to use can also be solved.

[Brief explanation of the drawing]

Figures 1 a to e are diagrams showing a conventional parting chip and its parting process, Figure 2 is a diagram showing parting process using a conventional triangular parting chip, and Figures 3 a to c
4 is a diagram showing the basic shape of the cutting tip of the present invention, FIGS. 4 a to 4 c are configuration diagrams showing an embodiment of the cutting tip of the present invention, and FIG. 6A and 6B are block diagrams showing other embodiments of the present invention. 1... Cutting tip, 2... Cutting blade, 2a, 2
b, 2c... Triangular chip cutting blade, 3... Workpiece, 4... Corner part of cutting blade, 5... Bit holder, 6... Triangular chip, 7... Concave portion, 8... Convex portion, 9 ...chip breaker, 10...presser foot, 11...tightening bolt, 12...rake face, τ
... Back taper, γ _e ... Front relief angle, γ _s ... Side relief angle, P ... One end of concave surface, α ... Rake angle, β
...Knife angle.

Claims (1)

[Scope of utility model registration request] In a throw-away type parting tip having a substantially rectangular parallelepiped shape, the first of a pair of opposing first and second surfaces of the tip body.
A first cutting knife is provided on a predetermined side of the surface, and
A second cutting knife is provided on one side of the second surface that is orthogonal to the predetermined side, and a side relief angle is provided to the first cutting knife and the second cutting knife, and from the cutting knife. A throw-away cutting tip characterized in that a back taper is provided toward the rear edge of the tip.