JP2001315018A - Side cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a side cutter capable of reducing the cutting resistance, and the load to be applied to the edge of a throw away tip, elongating the service life of the edge, and providing the stable cutting. SOLUTION: The edge having an extended cutting edge 46 is mounted in the thickness direction of the chips 36 and 37, a negative axial rake angle αis determined on the edge of the chip, and the chips are fixed to a cutter body 32 in a state that a side face perpendicular to the thickness direction of each chip is received by a cutter body part, and a side face vertical to the width direction is received by a chip locator 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side cutter having a throw-away type insert, and more particularly, to the use of an axial angle for the cutting edge of the insert to reduce the cutting vibration and cutting resistance generated when performing groove machining or the like. The present invention relates to a side cutter that suppresses, stabilizes, and enables high-efficiency cutting.

[0002]

2. Description of the Related Art Conventionally, tools used for cutting in a machine tool include a cutting tool, an end mill, a side cutter, and the like. Of these tools, a side cutter is generally used for efficient groove machining. . The end mill has an advantage that the tool can be automatically changed easily and is a tool suitable for groove machining in an unmanned process by a machining center. On the other hand, since the side cutter has a large load on the cutting edge of the insert, unattended machining is impossible due to the large loss of the insert blade.However, in a machine tool having a highly rigid structure and a motor with a high horsepower, it is difficult to use other tools. It is possible to perform much more efficient groove processing than that.

[0003] Conventional chips used for the side cutter for groove processing include a high-speed steel tip and a cemented carbide tip in terms of material. High-speed steel chips are often used for side cutters used for relatively simple grooving on small machine tools, and carbide tips are used for side cutters used for grooving on medium and large machine tools. Is done. This type of carbide chip includes a brazing type and a throw-away type. At present, a carbide throw-away chip is mainly used. In this carbide indexable insert, a blade shape corresponding to chip countermeasures is devised, and various coatings are applied in order to improve the life of the cutting edge.

The side cutter for grooving has a larger body diameter than other cutters, and uses a low speed range to obtain the same cutting speed as a small-diameter cutter. The resistance to one tooth increases, and especially when the cutting edge is a negative type, a particularly large resistance is generated.

[0005] Further, in the groove machining by the side cutter,
Although slightly different depending on the depth of the groove, there is a feature that the cutting length involved in cutting per one rotation of the cutter is very short, about 1/8 of the outer peripheral length of the side cutter body. Since the side cutter works in this short 1/8 cutting length,
The number of blades involved in cutting is small, and the cutting process is intermittent cutting. In particular, at the start of cutting and at the end of cutting, cutting is performed with one blade, and a very loud intermittent sound is generated.

FIG. 9 shows a so-called negative-negative type side cutter in which the axial rake angle and the radial rake angle of the cutting edge of the conventional side cutter are both set to negative (negative). Although the cutting edge of the negative type is inferior to that of the positive type, the cutting edge is characterized by enduring severe cutting and having a long tool life.

In FIG. 9, FIG. 9A is a diagram showing the side cutter in a radial direction, and FIG. 9B is a diagram showing the side cutter in an axial direction. Reference numeral 10 denotes a cutter body, and reference numeral 12 denotes a throw-away type tip. α is the negative axial rake angle.
As shown in FIG. 9A, chip pockets 11 are formed at predetermined intervals on the outer peripheral portion of the cutter body 10.
In the chip 12, a groove 13 for mounting the chip 12 and a groove 15 for mounting the chip locator 14 are formed adjacent to the chip pocket 11. The chips 12 are arranged in the circumferential direction such that the chips forming the left cutting edge 16a and the chips forming the right cutting blade 16b are alternately distributed left and right. This figure 9
The tip 12 is a tip in which four cutting edges are provided for one tip, and the width of the cutting edge can be widened at one corner, and is fixed to the cutter body 10 by a tip holding screw 16. Such a negative-type tip edge shape is compact and economical in terms of inserts, and is a generally adopted method. However, the cutting force is large and tends to accelerate the deterioration of machine tools.

FIG. 10 shows a side cutter having a so-called positive-positive type edge shape in which the axial rake angle α and the radial rake angle β of the edge of the tip 20 are both set to be positive. The chip 20 is attached so as to be sandwiched between a wedge 21 fixed by a screw 23 on the chip pocket 11 side and a locator 22 arranged on the back side of the chip 20. As shown in FIG. 10 (a), the chips 20 are such that the chips constituting the left cutting edge 20a and the chips constituting the right cutting edge 20b are alternately distributed left and right in the circumferential direction. It is the same as the negative type. Such a positive-positive type tip edge shape is inferior in cutting edge life to a negative type, but is excellent in sharpness.

The negative type shown in FIG. 9 and the negative type shown in FIG.
The positive / positive type of 0 is properly used depending on the use environment and the material of the processing object.

[0010]

In the conventional side cutter, a chip pocket 11 is required to enable deep groove machining.
Is taking a large amount. The set number of chips 12 and 20 is reduced by the amount of space for the chip pocket 11. In addition, since the width of one cutting edge of the tip 12 is relatively wide, the left cutting edge 12a and the right cutting edge 12b (tip 20
In this case, the cutting edge lap width A where the left cutting edge 20a and the right cutting edge 20b) overlap is relatively large. This cutting blade lap width A
This has the advantage of reducing the number of cutting edges in the design and reducing the manufacturing cost of the cutter, but has fewer cutting edges involved in cutting and inevitably results in intermittent cutting, and is more stable due to increased resistance and vibration. Cutting may be difficult.

Further, as shown in FIG. 10, since the axial angle α is provided, the direction of the cutting force acting on the insert 20 is deviated from the cutter body 10, but the backup of the locator 22 is weak. Due to the structure, the locator 22 may be damaged when receiving a large cutting resistance.

Furthermore, in the case of the positive-positive type, FIG.
As shown in (b), the lower half of the center of the chip 20 is clamped between the wedge 21 and the locator 22 in consideration of the chip discharge property. For this reason, the locator 22 is liable to be minutely deformed into a V shape due to the cutting resistance acting on the chip 20.
A small gap is generated between the rear surface of the locator 0 and the front surface of the locator 22, and the backup force of the chip is weakened. Once the chip breaks, the next cutting edge is further damaged by further resistance, and this phenomenon spreads in a chain fashion.

Accordingly, an object of the present invention is to solve the problems of the prior art, reduce the cutting resistance, reduce the load on the cutting edge of the insert, extend the life of the cutting edge, and realize stable cutting. It is to provide a cutter.

[0014]

In order to achieve the above-mentioned object, the present invention provides a side cutter having a plurality of inserts of a throw-away type arranged in a circumferential direction on an outer peripheral portion of a cutter body, wherein a cutting edge extends. The cutting edge is provided in the thickness direction of the chip, and a negative axial rake angle is set on the cutting edge of the chip, and the side surface perpendicular to the thickness direction of the chip is received by the cutter body portion and the side surface perpendicular to the width direction is received. The tip is fixed to a cutter body so as to be received by a tip locator.

According to the present invention, the main component of the cutting resistance applied to the insert can be received by the cutter main body.
The load on the chip locator can be reduced, and the cutting edge is provided in the chip thickness direction and the chip is mounted so that the chip width direction is oriented in the circumferential direction of the cutter body. Since the circumferential component force can be received from the width direction which is much stronger than the thickness direction, the chip strength can be enhanced.

It is preferable that the tip of the insert has a large axial rake angle of 30 degrees or more.
As a result, the cutting resistance gradually increases during cutting, and the cutting resistance becomes maximum when cutting is started with the entire cutting edge, so that a large cutting force is not instantaneously applied to the cutting edge when cutting is started. In addition, since the impact on the cutting edge can be reduced, it is possible to stably cut the cutting edge, prevent the cutting edge from being damaged, and significantly extend the tool life.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a side cutter according to the present invention will be described below with reference to the accompanying drawings. First Embodiment FIG. 1 shows a side cutter 3 according to a first embodiment of the present invention.
Indicates 0. FIG. 1A is a side view showing an arrangement of chips on an outer peripheral portion of a cutter main body 32 of the side cutter 30, and FIG. 1B is a plan view of the side cutter 30.

As shown in FIG. 1B, the cutter main body 30 is formed in a disk shape having a predetermined thickness, and is positioned coaxially with a tool arbor (not shown) at the center thereof. For this purpose, a centering hole 33 is formed. The main shaft of the machine tool is attached via a tool arbor,
It is connected to the main shaft by a bolt inserted into the cutter clamp hole 34. The rotation torque of the main shaft is transmitted to the cutter body 30 via the torque transmission key 35.

As shown in FIG. 1A, the cutter body 3
A plurality of grooves are formed in the circumferential direction in a zigzag manner on the outer peripheral portion of the zero, and the following throw-away type chips are attached so as to be embedded in the grooves.

The inserts of the throw-away type include a tip for the left blade and a tip for the right blade, which are sequentially arranged at predetermined intervals in the circumferential direction so as to be alternately and alternately distributed. And as the tip for this left blade,
The left outer cutting edge tip 36 and the left inner cutting edge tip 37 form a pair with each other, and as the right blade tip, the right outer cutting edge tip 38 and the right inner cutting edge tip 39 form a pair. It has become.

FIG. 2A is an enlarged view of a part of FIG. 1A, and FIG. 2B is an enlarged view of a part of FIG.

On the left and right sides of the outer periphery of the cutter body 32, first chip mounting grooves 41 for mounting the left outer cutting edge tip 36 and the right outer cutting edge tip 38 via the tip locator 40 are formed. Have been. Insert the tip 37 for the left inner cutting edge and the tip 39 for the right inner cutting edge into the tip locator 40.
The second chip mounting groove 42 for mounting via
The first chip mounting groove 41 is formed so as to be continuous with the front side in the cutter rotation direction with a step and communicates with the chip pocket 45.

In this embodiment, a rectangular piece is used for each chip, and an L-shaped chip locator 40 is used. This chip locator 40 receives two side surfaces perpendicular to the chip width direction. It has two restraining surfaces 40a and 40b forming a right angle so as to be restrained. Each of the chips 36 to 39 is combined with a chip locator 40 to form a rectangular shape as a whole, and a first chip mounting groove 41,
When fitted in the second chip mounting groove 42, the cutter body 32 receives the widest side surface (width direction) perpendicular to the thickness direction of the inside 39 of each chip 36, and the constraint surfaces 40 a and 40 b of the chip locator 40 It is designed to receive the side surface perpendicular to the width direction. The chips 36 to 39 are detachably fixed by chip holding screws 43, and the chip locator 40 is detachably fixed by locator holding screws 44.

FIG. 3 (a) is a sectional view taken along the line AA in FIG. 2 (b), showing the tip 36 for the left outer cutting edge and the tip 37 for the left inner cutting edge, and FIG. 3 (b) FIG. 3B is a cross-sectional view taken along the line BB in FIG.

On the left side of the outer peripheral portion of the cutter body 32, a left outer cutting edge tip 36 and a left inner cutting edge tip 37 are disposed with a step therebetween through a tip locator 40, and the right outer right edge is also located on the right side. A blade tip 38 and a right inner cutting blade tip 39 are arranged via a tip locator 40 with a step.

The chips 36 thus arranged on both the left and right sides
The cutting edges 46 to 39 are provided so as to extend in the chip thickness direction. Each of the cutting edges of the chips 36 to 39 is provided with a lateral clearance angle γ and a vertical clearance angle δ.

In the side cutter according to the present invention, the circumferential arrangement intervals of the cutting blades 46 in the outer peripheral portion of the cutter body 32 are set as follows. As shown in FIG.
Assuming that the pitch between the adjacent left outer cutting edge tip 36 and the left inner cutting edge tip 37 on the left edge is a pitch P1, the adjacent right outer cutting edge tip 38 and the right inner cutting edge on the right edge The blade interval between the blade tip 39 and the blade tip 39 is set to the same pitch P1. On the other hand, an adjacent left outer cutting edge tip 36,
The interval between the cutting edge and the tip 39 for the right inner cutting edge is set to a pitch P2 (P2> P1) different from P1. In this way, by combining different pitches with respect to the cutting edge interval between the front and rear adjacent chips, the arrangement of a large number of cutting blades 46 is set unequally, so that resonance during cutting is suppressed and cutting vibration is prevented. ing. In order to suppress cutting vibration and cutting noise, it is desirable that the pitch of the cutting edge interval is small and the number of cutting edges is large, but if the number of cutting edges is too large, the manufacturing cost of the cutter increases and the cutting resistance increases. It is not preferable because the minus side becomes larger than the plus side.

In the grooving by the side cutter 30, the blades involved in the actual cutting while the cutter body 32 rotates are the cutting blades in the cutting length range shown in FIG. 1 (b). This cutting length range varies depending on the depth of the groove, but is usually about 1/8 of the outer peripheral length of the cutter body 32. In order to maintain stable cutting, several cutting blades always enter the cutting length range of 1/8 of this outer circumference,
It is necessary to be involved in cutting, and therefore, the pitch of the cutting edge interval is at least within the cutting length range, at least the left inner and outer cutting blade tips 36 and 37 and the right inner and outer cutting blade tips 38,
Preferably, there is a set of 39.

In the side cutter 30 according to the present invention, each of the inserts 36 to 39 uses a throw-away insert having the same cutting edge configuration. Therefore, the shape of the throw-away tip 50 as a single body is shown in detail in FIG.

As shown in FIG. 4, cutting edges 46 are formed at four corners of the tip body 50 of one throw-away tip so that the tip can be used by changing the orientation of the tip upside down. I have. In the center of the chip body, a chip setting hole 49 for screwing the above-mentioned chip holding screw 43 is formed. In this case, a negative axial rake angle α is set to a large angle on the cutting edge 46 provided in the thickness direction at each corner.
The axial rake angle α is preferably 30 ° or more. In addition, 52 is a flat width following the cutting blade 46, and secures the side surface of the cutting blade 46 which is in close contact with the chip locator 40 when the chip is replaced.

FIG. 5 is a view showing a cross section taken along line CC in FIG. An R-squeeze surface 48 is provided at the corner of the chip body 50.
Has been made. The cutting blade 46 is formed in a blade shape by an R-squeeze surface 48, and a predetermined rake angle θ is set together with the above-mentioned axial rake angle α. Further, a land width 51 is provided at the tip of the cutting blade 46 to protect the cutting edge, and both end portions of the cutting blade 46 are R-shaped to increase the blade shape strength. Next, the cutting action of the side cutter configured as described above will be described. FIG.
When the side cutter 30 rotates in the rotation direction indicated by the arrow, a groove having a depth D and a width W is cut into the workpiece 100. Tip 37 for left inner cutting edge and tip 39 for right inner cutting edge
The chips shaved in the above-mentioned manner accumulate in the tip pocket 45, and the chips shaved by the left outer cutting edge tip 36 and the right outer cutting edge tip 38 become the left inner cutting edge tip 37 and the right inner cutting edge tip 39. Accumulate in the gap beside the.

Since the tips 36 to 39 of the left and right inner and outer blades have a large negative axial rake angle α at the cutting edge, the direction in which the cutting force F acts, as shown in FIG. It turns to 32 side. When the cutting force F is decomposed into an axial component Fa and a circumferential component Fb, the cutter body 32 can receive the axial component Fa of the cutting force F applied to the chips 36 to 39. Therefore, the load on the chip locator 40 can be reduced, and the chip locator 40 can be prevented from being damaged.

The tips 36 to 39 are provided with the cutting blade 46 in the chip thickness direction and mounted so that the chip width direction is oriented in the circumferential direction of the cutter main body 32. Since the component force Fb can be received from the width direction, which is much stronger than the thickness direction, the chip strength can be increased. In addition, since the cutting edge configuration of the chips 36 to 39 is set in the thickness direction, the cutting width of the cutting edge 46 becomes narrow, the load on the cutting edge 46 is reduced by that much, and the large axial rake angle α Since the cutting width is widened and the resistance is dispersed, the life of the cutting edge can be improved.

Next, a description will be given of the cutting action by making the cutting edge of the tip a reasonable cutting edge shape. FIG. 6 is a diagram showing the mechanism of the cutting action of the tip body 50.
When the side cutter rotates and the workpiece is fed at a predetermined cutting amount per blade, the cutting blade 46 starts cutting the workpiece. First, the cutting edge at the flat width 52 first contacts the workpiece. Since the cutting blade 46 has a large axial rake angle α, the range of the blade for cutting the workpiece gradually increases from one end of the cutting blade 46 to the other end. Along with this, the cutting force also gradually increases, and the cutting force becomes the maximum when the entire blade of the cutting edge 46 hits the workpiece and starts cutting with the entire cutting edge 46. As described above, since the cutting resistance gradually increases and the cutting resistance is maximized when cutting is started with the entire blade of the cutting blade 46,
With the start of cutting, a large cutting force does not momentarily load the cutting edge. Therefore, the cutting vibration can be reduced and the impact on the cutting edge can be reduced, so that the cutting can be prevented stably and the cutting edge can be prevented, and the tool life can be greatly extended.

Further, since the rake angle θ is set after setting the large axial rake angle of the cutting edge,
There is an advantage that the effect of reducing the cutting resistance applied to the cutting edge is doubled. This is because, by providing the rake angle θ, the cutting edge not only pushes the workpiece but also pulls the workpiece, thereby further reducing the cutting resistance.

Second Embodiment Next, a side cutter according to a second embodiment of the present invention will be described. FIG. 7 shows a side cutter according to a second embodiment of the present invention. In the side cutter according to the first embodiment, four chips 36 to 39 forming an inner blade and an outer blade on the left and right sides are arranged as a set in the circumferential direction. A pair of a left cutting edge tip 60 and a right cutting edge tip 60 forming a right edge are arranged in the circumferential direction. The side cutter according to the second embodiment as described above is applied to groove processing in which the processing width W of the groove is relatively small, and the thickness of the left cutting edge tip 60 and the right cutting edge processing tip 61 is respectively different. The processing width W of the groove is covered. The same chip as that of the first embodiment is used as a single chip,
The cutting edge 46 has a large negative axial rake angle α
Is set.

A left cutting edge tip 60 adjacent to the front and rear sides is also provided.
And the pitch interval between the right cutting blade tip 61 are not constant,
It is set to be unequal. In this case, the right cutting edge tip 6
The pitch interval P1 between 0 and the left cutting edge tip 61 adjacent to the front side is different from the pitch interval P2 between the left cutting edge tip 61 adjacent to the rear side. This allows
Resonance generated during cutting is suppressed, and stable cutting can be performed.

Third Embodiment FIG. 8 is a view showing a throw-away tip of a side cutter tool according to a third embodiment of the present invention from four directions. In this indexable insert, the cutting edge 70 formed on the cutting edge is formed in the thickness direction of the insert, and the cutting edge shape in which a large axial rake angle α and a rake angle θ are set is the first embodiment. It is the same as the chip of the embodiment, but is different in that a convex blade shape that curves convexly is used as the cutting blade 70 and that the rake face 71 that forms the rake angle θ is largely chamfered. As shown in FIG. 4, in the case of the cutting blade 46 having a straight blade shape, the chip may be curled in a spiral shape to increase rigidity and cause a large cutting resistance.
In the case of 0, the chip has an arc shape without curling, and thus has no rigidity. In addition, by increasing the space of the squeeze surface 71, the separation of the chips from the cutting edge is improved.

Further, chips having nicks 72A and nicks 72B are separately provided in the chip body, and these chips are alternately attached to the cutter body 32, so that chips can be reduced in size and the chip discharge property can be further improved. This is effective in preventing chip pockets from clogging and protecting the finished surface of the groove.

[0040]

As is apparent from the above description, according to the present invention, since the cutting force is reduced and the large cutting force is not instantaneously applied to the cutting edge of the insert, the life of the cutting edge is reduced. It can be greatly extended, and the load on the cutting edge and tip locator can be reduced, so that stable and high-efficiency cutting can be performed even with intermittent cutting of the side cutter. Therefore, deep groove machining using a conventional side cutter, which can be performed only with a machine tool having high rigidity, can be realized with higher productivity at a more economical efficiency with a machine tool having average rigidity.

[Brief description of the drawings]

FIG. 1 is a view showing a first embodiment of a side cutter according to the present invention, and FIG. 1A is a side view of a cutter main body, and FIG.
(B) is a front view of the cutter body.

2 (a) is an enlarged view of FIG. 1 (a), and FIG. 2 (b) is an enlarged view of FIG. 1 (b).

3A is a diagram showing a cross section taken along the line AA in FIG. 2B, and FIG. 3B is a diagram showing a cross section taken along the line BB in FIG. 2B.

FIG. 4 is a perspective view of a single chip according to the first embodiment;

FIG. 5 is a diagram showing a CC section in FIG. 4;

FIG. 6 is a diagram illustrating a cutting mechanism of the side cutter according to the present invention.

FIG. 7 is a view showing a second embodiment of the side cutter according to the present invention.

FIG. 8 is a view showing a tip according to a third embodiment of the side cutter according to the present invention from four directions.

FIG. 9 is a diagram showing a conventional negative-negative type side cutter having a blade edge configuration.

FIG. 10 is a diagram showing a conventional positive-positive type side cutter having a blade edge configuration.

[Explanation of symbols]

 Reference Signs List 30 Side cutter 32 Cutter main body 36 Tip for left outer cutting edge 37 Tip for left inner cutting edge 38 Tip for right outer cutting edge 39 Tip for right inner cutting edge 40 Tip locator 45 Tip pocket 46 Cutting edge 48 Squeeze surface α Axial Rake angle θ Squee angle

Claims (6)

[Claims] 1. A side cutter having a plurality of inserts of a throw-away type arranged in a circumferential direction on an outer peripheral portion of a cutter body, wherein a cutting edge on which a cutting blade extends is provided in a thickness direction of the chip, and a cutting edge of the chip is provided on the cutting edge of the chip. A negative axial rake angle is set, and the chip is fixed to the cutter body so that a side surface perpendicular to the thickness direction of the chip is received by the cutter body and a side surface perpendicular to the width direction is received by the chip locator. And side cutter. 2. The side cutter according to claim 1, wherein the axial rake angle of the cutting edge of the tip is at least 30 degrees or more. 3. The side cutter according to claim 2, wherein a rake angle is further set at the cutting edge of the front tip. 4. The tip comprises a plurality of tips for a left cutting edge and a tip for a right cutting edge arranged in a circumferential direction on the cutter main body, and these many tips are arranged at unequally distributed cutting edge intervals. The side cutter according to claim 3, which is arranged. 5. The tip for left and right cutting blades comprises a pair of a tip for an outer cutting blade and a tip for an inner cutting blade, respectively.
5. The side cutter according to claim 4, wherein a plurality of chips are arranged at unequally-distributed edge intervals by combining edge intervals having different pitches between right and left cutting edges adjacent to each other in front and rear or between inner and outer cutting edges. 6. The side cutter according to claim 1, wherein the cutting edge of the tip has a convex cutting edge that is convexly curved.