KR920010885B1 - Throw away type insert cutter - Google Patents

Abstract

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Description

Drawaway face milling cutter

1 to 7 show one embodiment of the present invention, and FIG. 1 shows a bottom view of a front milling cutter.

2 is a cross-sectional view taken along the line (II)-(II) of FIG.

FIG. 3 is a view from the III-arrow direction of FIG. 2 showing the drawaway tip disposed; FIG.

FIG. 4 is a view seen from the direction of the IV arrow in FIG. 2 showing a state in which the drawaway tip is disposed in an axial rake angle. FIG.

5 is a view seen from the direction of the V arrow of FIGS. 3 and 4. FIG.

6 is a bottom view for explaining the comparison of drawaway tips of two types.

FIG. 7 is a view from the VII arrow direction of the drawaway tip in FIG. 6. FIG.

8 is a side view showing an example of a conventional front milling cutter.

* Explanation of symbols for main parts of the drawings

1: drawaway tip 2: main cutting edge

5: cutter body 6a: drawaway tip

6b: drawaway tip 10a: main cutting edge

10b: major cutting edge 0: axis

αa: shaft tilt angle αb: shaft tilt angle

The present invention relates to a drawaway type face milling cutter capable of preventing fine vibration of the cutter body.

In general, in the case of cutting using a front milling cutter, each drawaway tip is an interrupted cut that repeats cutting and non-cutting each time the cutter body rotates once. And drawaway tips are prone to deficiency.

Therefore, it is desired to be able to prevent the drawaway tip from being lost without minute vibration.

By the way, as a conventional front milling cutter, the so-called uneven split type front milling cutter as shown in FIG. 8 is known, for example.

The front milling cutter shown in this drawing has a plurality of draws spaced apart at an angle of (θ1) and an angle of (θ2) alternately in the circumferential direction at the distal end portion of the cutter body 1 which is rotated about the axis (0). Away tip 2... The drawaway tip 2 has the main cutting edge 3 and the sub cutting edge 4, and the sub cutting edge 4 is the feed direction of the cutter (arrow A in the drawing). And a fixed radial inclination angle, an axial inclination angle, and a coordinator angle are attached to the main cutting edge 3, respectively. .

In the above-described front milling cutter, rough cutting is performed by the main cutting edge 3 of the drawaway tip 2, while finishing cutting is performed by the sub-cutting blade 4 positioned parallel to the cutting direction of the cutter. Since it is performed, surface roughness of a cutting surface can be improved.

And a plurality of drawaways 2... Are arranged at uneven intervals in the circumferential direction of the cutter body, so that chips having different thicknesses are alternately generated.

For this reason, since the period and magnitude of the impact force received by the cutter body become irregular, there is an advantage that the cutter body is less susceptible to resonance and is effective for preventing fine vibration.

However, in the face milling cutter as described above, there is a problem that it cannot sufficiently cope with the request of preventing the fine vibration of the cutter body and preventing the drawaway tip.

That is, in the above-mentioned front milling cutter, since the radial inclination angle, the axial inclination angle, and the nose holder angle of the main cutting edge of the drawaway tip are all the same, the main cutting edge 3 of each drawaway tip 2 receives. Although the magnitude of the impact force varies slightly depending on the thickness of the chip produced, the direction in which the impact force acts depends on each major cutting edge (3). Are all the same for.

For this reason, the impact force which always points in the same direction is applied to the main cutting edge 3 of each drawaway tip 2, and this impact force is transmitted to the cutter main body 1. As shown in FIG.

The direction of the impact force transmitted to the cutter body 1 is determined by the drawaway tips 2... Since it is the same with respect to, the cutter body 1 tends to resonate easily.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a drawaway type front milling cutter which hardly causes the cutter body to resonate and cause minute vibrations, and thus effectively prevents a drawaway tip from being lost. do.

The drawaway type front milling cutter of the present invention has a plurality of drawaway tips attached to the distal end of the cutter body, and a part of the drawaway tips is the shaft inclination angle of the main cutting blade and the shaft inclination angle of the remaining cuttingaway tip. It is arranged to be different from.

In the front milling cutter of the above-described configuration, since the direction of the impact force applied to the main cutting edge is different according to the axial inclination angle of the main cutting edge, the direction of the impact force transmitted to the cutter body varies depending on the drawaway tip.

For this reason, the cutter body rarely resonates and causes minute vibrations.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 7.

In Fig. 1, reference numeral 5 denotes a cutter body, and six drawaway tips 6 of the same shape and size are formed on the outer periphery of the tip. The wedge member 8 and the clamp screw 9 are attached and detached via the supporter 7, respectively.

These drawaway tips 6... Is divided into two types of the axial inclination angle αa at the position corresponding to the radial direction of the main cutting edge 10 and the one of αb (where αa and αb are all right angles αa <αb). In other words, the main cutting edge 10a located on the inner circumferential side of the cutter body 5 of one drawaway tip 6a has a radial line L1 (L2), which divides the outer circumference of the cutter body 5 into six equal parts. It is located on the plane S1 which is spaced apart by the dimension X from the back of the rotation direction L1 which is one of and is parallel to the axis 0.

Moreover, the main cutting edge 10b located in the inner circumferential side of the cutter body 5 of the other drawaway tip 6b has a radial line L3 having an angle of (β) with respect to the radial line L2. Is spaced apart by the dimension Y (here, Y <X) in the rearward direction of rotation, and is located on a plane S2 parallel to the axis 0.

Here, the dimension X (Y) and the angle β are each sub-cutting edges 11a, 11b... Is set so as to be positioned on a radius line that divides the outer periphery of the cutter body 5 into six equal parts.

And as shown in FIG. 3 and FIG. 4, the main cutting blades 10a and 10b which are located in the outer peripheral side of the cutter body 5 of each drawaway tip 6a and 6b are all the above-mentioned planes ( An angle (δ) with respect to the plane S3 which holds an angle (γ) with respect to S1 (S2) and crosses the plane S1 (S2) at right angles as shown in FIG. It is positioned to hold.

As a result, the major cutting edges 10a and 10b have an angle of γ1 with respect to the planes S1 and S2 as viewed from the bottom (FIG. 1).

Here, angle (gamma) and angle (delta) are set so that the auxiliary cutting blades 11a and 11b may be parallel to the feed direction of a cutter (the arrow A direction in FIG. 1).

By this arrangement, the radial inclination angle on the major cutting edge 10a is a radial line passing through any point Pa on the plane S1 and the main cutting edge 10a, as shown in FIG. It becomes the angle (lambda) a which (La) makes.

Moreover, the radial inclination angle of the said main cutting edge 10b becomes the angle (lambda) b which consists of the plane line S2 and the radial line Lb through arbitrary points Pb on the main cutting edge 10b. (Where λa and λb are all right angles λa> λb).

As shown in FIG. 7, the axial inclination angle of the main cutting edge 10a is the plane Sa and the drawaway passing through the axis 0 and the radius line La, as shown by the arrow in the radial line La direction. The angle αa is formed at the rake surface 12a of the tip 6a.

Moreover, the axial inclination angle of the main cutting edge 10b is an angle formed between the plane Sb and the inclined surface 12b passing through the axis 0 and the radius line Lb as viewed by the arrow in the radius Lb direction, and the plane Sb. ) And an angle αb formed by the straight lines Pb and Qb.

These two drawaway tips 6a and 6b are alternately arranged in the circumferential direction of the cutter body 5.

In the drawaway type front milling cutter, the drawaway tip 6a is different because the axial inclination angle between the main cutting blade 10a of the drawaway tip 6a and the main cutting blade 10b of the drawaway tip 6b is different. The direction of the impact force received by the main cutting edges 10a and 10b is different in the case of performing the cutting process using the cutting edge) and the case of the cutting process using the drawaway tip 6b.

For this reason, the direction of the impact force transmitted to the cutter body 5 differs depending on the drawaway tips 6a and 6b, and the cutter body 5 resonates and there is almost no fine vibration, and the drawaway tips 6a and 6b0 The deficiency of can be effectively prevented.

In addition, since the direction of the inclination angle αb of the major cutting edge 10b is in a positive direction than the axis inclination angle αa of the other major cutting edge 10a, the ejection property of the chip can be improved and the cutting resistance can be reduced. have.

Each drawaway tip 6a, 6b is provided. Since the mutually opposite positions with respect to the reference plane S1 and S2 are the same, as shown in FIG. 5, the shape of the recess 5a for attaching the drawaway tips 6a and 6b is the same. The cutting body 5 can be easily machined.

In addition, in the above-described embodiment, the angles with respect to the planes S1 and S2 of the major cutting edges 10a and 10b are each γ, and the angles with respect to the plane S3 are each δ. It is not limited to the same structure, You may change the axial tilt angle by changing the angle (gamma) and the angle (delta) by the main cutting edges 10a and 10b.

Further, the arrangement may be appropriately changed, such as arranging two drawaway tips 6b and 6b between two drawaway tips 6a and 6b adjacent in the circumferential direction.

In addition, in the above embodiment, the auxiliary cutting edges 11a, 11b,... Although the dimension X (Y) and the angle (beta) are set so that it may be located at equal intervals in the circumferential direction of this cutter body 5, you may make it located at the same interval.

Further, in the above embodiment, the drawaway tip 6... Are divided into two types of αa and αb of the inclination angle, but may be classified into many more types.

As described above, in the drawaway type front milling cutter of the present invention, a drawaway tip of a plurality of drawaway tips mounted on the distal end of the cutter body has an axis tilt angle of the main cutting edge of the main cutting edge of the remaining drawaway tip. Since it is arranged to be different from the inclination angle, the direction of impact force transmitted to the cutter body varies depending on the drawaway tip.

For this reason, the effect that the cutter body hardly oscillates due to resonance and that the drawaway tip can be effectively prevented can be obtained.

Claims (1)

To the drawware type front milling cutter formed by detachably attaching a plurality of drawaway tips 1 holding the main cutting edge 2 to the distal end of the cutter body 5 which is rotated about the axis 0. In this case, a part of the drawaway tip 6a is arranged differently from the axis tilt angle αb of the main cutting edge 10a of the main cutting edge 10a so as to be different from the axis tilt angle αb of the main cutting edge 10b of the remaining drawaway tip 6b. Drawaway type front milling cutter, characterized in that made.

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