JPH0976205A - Milling cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve working atmosphere by a method wherein the impact cutting resistance of a milling cutter is reduced to contrive the high efficiency of cutting and reduce cutting sound. SOLUTION: One thread of screw type spiral groove 13 is cut on a body 12 whereby one thread of spiral protruded body 14 is provided. The protruded thread body is provided with a plurality of notched units 15 at intersecting positions between two pieces of imaginary twisted lines positioned on the circumference of the body with the central angle of 180 deg. while a plurality of tip seats 16 are provided at the rear side of rotation of the notched parts 15. The twisting angle of the tip seat 16 is 0 deg.. A cutting edge or tip 17 is fixed to respective tip seats detachably through screws. The tip is straight edge cutter and, therefore, spiral cutting, effected by a milling planer having spiral cutting edges, can not be effected, however, cutting near to the spiral cutting can be effected by shortening the length of the cutting edge. Accordingly, impact cutting resistance is reduced whereby a cutting having big cutting resistance is permitted and the generation of cutting sound can be reduced. The shape of the body 12 can be truncated conical type other than a circular column type.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a milling cutter used for cutting wood, wood-based materials, metal materials, plastic materials and the like.

[0002]

2. Description of the Related Art Conventionally, as a milling cutter of this type, for example, Japanese Patent Laid-Open No. 4-33110.
As shown in Japanese Unexamined Patent Publication No. 2 (see FIG. 11), at least one (two in the figure) screw-shaped spiral groove 2 is formed on the outer peripheral surface of the cylindrical body 1 to form a spiral convex strip 3 Is provided, a notch is formed in the ridge 3 in order to dispose the cutting edge at the intersection of the imaginary line L parallel to the axis of the cylindrical body and the ridge 3, and the chip seat 4 is formed in the notch. It has been known that a flat milling cutter is provided in which a sintered body chip 5 of cemented carbide or the like serving as a cutting edge is fixed to the chip seat 4 by brazing or the like.
According to FIG. 11, assuming that the effective length of the flat milling cutter is T and the pitch of the spiral ridges (synonymous with the pitch of JIS screw terms) is P, n = T / P or n + 1 cuts on the imaginary line L. There is a blade. However, n is an integer value with the remainder truncated.

However, in this flat milling cutter, since n or n + 1 cutting edges are difficult to work at the same time during cutting,
There is a problem that a large cutting resistance is generated due to shock, a vibration with a large amplitude is generated, and a cutting noise is considerably increased. The present invention is intended to solve the above-described problems, and it is possible to improve the efficiency of cutting by reducing impact cutting resistance and enabling heavy-duty cutting, and to reduce cutting noise. It is an object of the present invention to provide a milling machine that can improve the working environment by doing.

[0004]

Means for Solving the Problems and Effects of the Invention In order to achieve the above-mentioned object, the structural feature of the invention according to claim 1 is that the body is cylindrical or frustoconical, and that it is placed between both ends of the body. The spiral ridge provided by cutting at least one thread-shaped spiral groove on the outer peripheral surface and the ridge on the outer peripheral surface of the body at equal intervals with respect to the circumference and with respect to the axis A plurality of notches cut into the ridge at or near the intersection of the ridge with one or more virtual twist lines drawn on the helix with different twist angles, and in or within the notch. This is to provide a chip that becomes a cutting edge that is detachably fixed at a position facing the notch.

By configuring the invention according to claim 1 as described above, since the plurality of chips are arranged at a constant interval on the virtual twist line, the spiral formed by the cutting edges spirally discontinuously arranged. Cutting is possible. In addition, when cutting the work material, the cutting edges are distributed almost all around the milling cutter, resulting in discontinuous cutting that is almost continuous. As a result, when cutting the work material with the milling cutter, the cutting edges are sequentially pushed into the work material according to the twisted state, so that a large cutting resistance does not occur shockfully and the occurrence of vibration with a large amplitude can be suppressed. it can. Therefore, heavy cutting with large cutting resistance can be performed correspondingly, and cutting efficiency can be improved. Further, by using this milling cutter, the cutting noise can be significantly reduced and the working environment can be improved.

Further, the structural feature of the invention according to claim 2 is that in the milling cutter according to claim 1, the cutting edge of the chip is a straight blade. With the above configuration, in addition to the effect of the invention according to claim 1, it is easy to manufacture the chip seat by cutting the notch in the ridge so that the chip of the straight blade can be fixed. Therefore, the manufacturing cost is not increased as compared with the conventional case.

Further, the structural feature of the invention according to claim 3 is that in the milling cutter according to claim 1, the cutting edge of the chip is a twisting edge. With the above-described configuration, each cutting edge can perform spiral cutting that is similar to a milling cutter having a spiral cutting edge. As a result, the effect of the invention according to claim 1 can be obtained more reliably.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of an end mill 10 according to the first embodiment. The end mill 10 has a cylindrical shape, and includes a shank 11 and a body 12 coaxially connected to the shank 11. Body 1
One threaded spiral groove 13 is formed in the thread 2, and as a result, one threaded ridge 14 is provided in a spiral shape shown by a chain double-dashed line in the body development view of FIG. And the ridge 14
Is the equicenter angle position of the circumference of the body 12 (here, 180).
In order to arrange the straight blade at the intersection of the two virtual twist lines L1 and L2 located at the (.degree. Position), a plurality of cutout portions 15 are provided, and a plurality of tip seats are provided behind the cutout portions 15 in rotation. 16 are provided. The twist angle of the tip seat 16 (the angle of inclination of the surface of the tip seat with respect to the axis of the body) is 0 °.
The rotation direction of the end mill is counterclockwise as viewed from the end surface of the body.

As shown in FIGS. 1 and 3, a tip 17 as a cutting edge is brought into contact with a bottom surface of a notch portion serving as a radial reference and is detachably fixed to each tip seat 16 with a screw. ing. Here, in addition to the above cutting edge, a tip 18 is also provided as a bottom cutting edge. Since the tip 17 is a straight blade, the end mill 10 does not perform spiral cutting like a flat milling cutter having a spiral cutting edge, but shortens the length of the cutting edge (for example, about 10 mm or less) and discontinues. However, by arranging in a spiral shape, it is possible to perform cutting close to spiral cutting.

The end mill 10 having the above-described structure is capable of spiral cutting similar to a flat milling cutter having spiral cutting edges, and is sequentially cut by the tips 17 distributed over substantially the entire circumference of the body 12. Therefore, the shocking cutting resistance is smaller than that of the type shown in the prior art, and vibration with large amplitude is less likely to occur. Then, heavy cutting with a large cutting resistance can be performed correspondingly, and the efficiency of cutting can be improved. In addition, cutting noise is reduced and the working environment is improved. Further, the respective chips 17 are arranged spirally on the cylindrical surface of the body 12 as a whole,
Since the cutting edge of each individual tip is a straight blade, it is more complicated to manufacture than the conventional end mill to form the tip seat 16 by cutting the notch 15 parallel to the axial direction on the ridge 14. In addition, it does not increase the manufacturing cost. In the present embodiment, the tip seat is formed on the wall surface of the cutout portion, but it is formed on the outer peripheral surface of the ridge so that the cutting edge faces the cutout portion by fixing the tip to the outer peripheral surface. It may be placed at.

Next, a second embodiment will be described. FIG. 4 is a partially cutaway front view and side view of the flat milling cutter 20 according to the second embodiment. This flat milling cutter 20 is provided with a cylindrical body 21,
The body 21 is formed with two screw-shaped spiral grooves 22a and 22b, so that two projecting ridges 23a and 23b are formed.
b is provided. Each ridge 23a, 23b is shown in FIG.
As shown in the unfolded view of the body of FIG. 4, four virtual twist lines L1 located at four positions with a central angle of 90 ° on the circumference of the body 21
A plurality of cutout portions 24a, 24b are formed to place the straight blades at the intersections with .about.L4. Chip seats 28a and 28b are formed in the cutout portions 24a and 24b, respectively. On the chip seat, a step serving as a radial position reference of the chip is formed near the bottom surface of the notch. The twist angle (the angle of inclination of the surface of the tip seat with respect to the axis of the body) of the tip seats 28a and 28b is 0 °. Tip seat 28
On the front side of the flat milling cutters of a and 28b, the tip 26
a, 26b are brought into contact with each other, and the tips 26a, 26b are provided with ridges 23a, 23 in front of the cutouts 24a, 24b.
b through the back seats 25a and 25b by means of screws screwed into the through screw holes 27a and 27b provided in the chip seats 28a and 28b.
It is fixed to b. The rotation direction of the flat milling cutter is shown in Fig. 4.
It is clockwise when viewed from the side of the body shown in. Chip 26
The cutting edges of a and 26b are straight blades. The length of the cutting edge is preferably 20 mm or less. Further, by using the square chips 26a and 26b, a cutting edge can be formed on each side, and even if the cutting edge is worn, the cutting edge can be repeatedly used three times.

As a result, the flat milling cutter 20 also
Similar to the end mill 10 according to the first embodiment described above, spiral cutting similar to a flat milling cutter having a spiral cutting edge is possible, and cutting is performed by the chips 26a and 26b dispersed almost all around the body 21. Therefore, the shocking cutting resistance is smaller than that of the type shown in the prior art, and the vibration with large amplitude is less likely to occur. And
Heavy cutting with large cutting resistance is also possible, and the cutting efficiency can be improved. In addition, cutting noise is reduced and the working environment is improved. Furthermore, each chip 26
Although a and 26b are arranged spirally on the cylindrical surface of the body 21 as a whole, the cutting edge of each individual chip is a straight blade,
Notch 2 that is parallel to the axial direction to the ridges 23a and 23b
Forming the chip seats 25a and 25b by grinding 4a and 24b does not complicate the manufacturing process as compared with the conventional flat milling cutter and does not increase the manufacturing cost.

Next, a modified example 1 of the second embodiment will be described. FIG. 6 is a side view and a partially developed view of the flat milling cutter 30 according to the first modification. This flat milling cutter 30 has the same structure as the flat milling cutter shown in the second embodiment, but has an L-shaped backing 35a having an L-shaped cross section.
The tip 36a, 3
Chip seats 38a, 38 in which the front surfaces of the chips 36a, 36b are formed on the wall surfaces of the notch while engaging the back surfaces of the 6b.
b to be abutted and inserted into the notches 34a and 34b,
Fixing to the notch portions 34a, 34b is performed by the wedges 39a, 39
The difference is that the screws 37a and 37b are provided through the through screw holes provided in b. Note that the chips 36a and 36b
The reference position in the radial direction is the engaging portion of the L-shaped backers 35a and 35b, and the cutting edges are formed at two opposite sides of the tip. The effects of the flat milling cutter 30 configured as described above are similar to those of the flat milling cutter shown in the second embodiment.

Next, a modified example 2 of the second embodiment will be described. FIG. 7 is a side view and a partially developed view of the flat milling cutter 40 according to the second modification. This flat milling cutter 40 has the same configuration as the flat milling cutter shown in the first modification, but the L-shaped backing seats 45a and 45b are formed in the opposite directions to the L-shaped backing seats 35a and 35b in the first modification. There is. Then, the tip seats 48a, 48b are formed by forming the wedges 49a, 49b on the surfaces of the tips 46a, 46b while engaging the rear surfaces of the tips 46a, 46b with the engaging portions on the inner rear surfaces of the L-shaped backers 45a, 45b. The cutouts 44a, 44b.
The fixing to b is performed by screws 47a and 47b through through screw holes provided in the wedges 49a and 49b. The effects of the flat milling cutter 40 configured as described above are similar to those of the flat milling cutter shown in the first modification.

Next, a third embodiment will be described. FIG. 8 is a partially cutaway front view and side view of a flat milling cutter 50 according to the third embodiment, and FIG. 9 is a body development view thereof. This flat milling cutter 50 is the flat milling cutter 20 of the second embodiment, and the twist angles (body of body) of the cutouts 54a, 54b provided by cutting out each of the projecting strips 53a, 53b (same as 23a, 23b). Instead of 0 °, the inclination angle with respect to the axis is set to 10 °, which is the same as the virtual twist line. This notch 54
a and 54b have a back seat 55 having a shape similar to that of the second embodiment.
The a, 55b and the chips 56a, 56b are inserted and fixed. Since each cutting edge has a short length, a straight cutting edge can be used as a twisting blade.

As a result, the flat milling cutter 50 has the above-mentioned second
The flat milling machine 20 according to the embodiment of the present invention can perform spiral cutting more similar to a flat milling cutter having continuous spiral cutting edges. Also, the flat milling machine 50 is a flat milling machine 20.
Compared with, the impact cutting resistance becomes smaller, the vibration with large amplitude is less likely to occur, the cutting efficiency is further enhanced, and the cutting noise is further reduced. In addition, the flattening mill 20
It's a bit more complicated and costly compared to, but it's cheaper than a flat milling cutter with a spiral helix.
As a modification of the third embodiment, the second
Alternatively, the L-shaped backing, the wedge and the tip shown in the modified example 1 or modified example 2 of the embodiment may be used instead.

Next, a fourth embodiment will be described. FIG. 10 is a partially cutaway front view of the milling cutter 60 according to the fourth embodiment. This milling cutter 6
No. 0 is provided with a frustoconical body 61.
A screw-shaped one spiral groove 62 is formed in this, and thereby one ridge 63 is provided. Ridge 63
Is a plurality of notches cut to arrange the straight blades at the intersections with the two twisted lines (only L1 is shown) located at two positions with a central angle of 180 ° on the circumference of the body 61. 64
Is provided. A tip seat 68 is formed in each notch portion 64. On the chip seat, a step serving as a radial position reference of the chip is formed near the bottom surface of the notch.
The twist angle of the seat 68 (the angle of inclination of the surface of the seat with respect to the axis of the body) is 0 °. The tip 66 is brought into contact with the tip seat 68 on the front side of the milling rotation.
Is fixed to the chip seat 68 via the back seat 65 by a screw screwed into the through screw hole 67 provided in the convex strip 63 on the front side of the rotation of the notch portion 64. The rotation direction of the milling cutter is clockwise as viewed from the left side surface of the body shown in FIG. The cutting edge of the tip 66 is a straight blade, and the length of the cutting edge is preferably 20 mm or less. Also, by using a square tip 66, cutting edges can be formed on each side,
Even if one cutting edge wears, it can be used three times more.

As a result, the milling cutter 60 is also capable of spiral cutting similar to a milling cutter having spiral cutting edges, like the flat milling cutter 20 according to the second embodiment, and is dispersed in the body 61. Since the cutting is performed by the tip 66, the shocking cutting resistance becomes smaller than that of the conventional one, and the vibration with large amplitude is less likely to occur.
And heavy cutting with large cutting resistance is also possible,
The efficiency of cutting can be improved. In addition, cutting noise is reduced and the working environment is improved. Further, the respective tips 66 are arranged spirally on the truncated conical surface of the body 61 as a whole, but since the cutting edges of the individual tips are straight, the notches 64 parallel to the ridge 63 in the axial direction. Forming the chip seat 65 by grinding the slab does not complicate the manufacturing process as compared with the conventional milling cutter and does not increase the manufacturing cost.

Regarding the milling cutter 60 as well, the tip 66 can be fixed to the tip seat 68 by the method shown in the first and second variations. In addition, the third
As shown in the embodiment of FIG.
4 with a predetermined helix angle, and insert the tip 66 into the tip seat 6
By fixing to 8 it is possible to substitute a straight cutting edge as a twisting edge.

Incidentally, in the end mill and the milling machine shown in the above-mentioned respective embodiments, the size of each part, the helix angle, etc. may be appropriately changed according to the purpose and application of cutting. Further, two or more milling cutters of the present invention may be coaxially combined. Further, the cylindrical and frustoconical body to which the present invention is applied includes a cylindrical body having a spindle hole at the center. Further, in each of the above embodiments, a plurality of virtual twist lines are used for the milling cutter, but one virtual twist line may be used.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing an end mill according to a first embodiment of the present invention.

FIG. 2 is a development view of a body portion of the end mill according to the first embodiment.

FIG. 3 is a front view, a plan view and a side view showing a tip of the end mill.

FIG. 4 is a partially cutaway front view and a side view of a flat milling cutter having a cylindrical body according to a second embodiment.

FIG. 5 is a development view of a body portion of a flat milling cutter according to a second embodiment.

FIG. 6 is a side view and a partially developed view of a flat milling cutter according to Modification 1.

FIG. 7 is a side view and a partially developed view of a flat milling cutter according to Modification 2.

FIG. 8 is a partially cutaway front view and side view of a flat milling cutter according to a third embodiment.

FIG. 9 is a development view of a flat milling cutter according to a third embodiment.

FIG. 10 is a partially cutaway front view of a frustoconical body milling machine according to a fourth embodiment.

FIG. 11 is a front view of a flat milling cutter according to a conventional example.

[Explanation of symbols]

10 ... end mill, 11 ... shank, 12 ... body, 1
3 ... spiral groove, 14 ... ridge, 15 ... notch, 16 ...
Tip seat, 17 ... Tip, 20 ... Flat milling cutter, 21 ... Body, 22a, 22b ... Spiral groove, 23a, 23b ... Convex body, 24a, 24b ... Notch portion, 25a, 25b ... Back seat, 26a, 26b ... Chip, 30 ... Flat milling cutter, 34
a, 34b ... notch, 35a, 35b ... L-shaped backing,
36a, 36b ... Chip, 40 ... Flat milling cutter, 44a,
44b ... Notch, 45a, 45b ... L-shaped backing, 46
a, 46b ... Chip, 50 ... Flat milling cutter, 54a, 54
b ... Notches, 55a, 55b ... Backing, 56a, 56
b ... Tip, 60 ... Milling cutter, 63 ... Convex body, 64 ... Notch portion, 65 ... Back seat, 66 ... Chip, 68 ... Chip seat.

Claims (3)

[Claims] 1. A cylindrical or frustoconical body, and a spiral ridge provided by cutting at least one threaded spiral groove on the outer peripheral surface between both ends of the body. An intersection of the one or more virtual twist lines drawn on a spiral having a twist angle different from that of the convex strip with respect to the axis on the outer peripheral surface of the body and the axis, or the intersection thereof. A plurality of cutouts cut in the convex body at a nearby position, and a chip serving as a cutting edge detachably fixed in the cutouts or at a position facing the cutouts are provided. And a milling cutter. 2. The milling machine according to claim 1, wherein the cutting edge of the chip is a straight blade. 3. The milling machine according to claim 1, wherein the cutting edge of the tip is a twisting edge.