JP3976985B2 - Side cutter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a side cutter having a throw-away tip, and in particular, adopts an axial angle at the tip of the tip, suppresses cutting vibration and cutting resistance generated when grooving or the like, and is stable and The present invention relates to a side cutter that enables highly efficient cutting.
[0002]
[Prior art]
Conventionally, tools used for cutting in machine tools include a cutting tool, an end mill, a side cutter, and the like, and among these, processing by a side cutter is generally used for efficient groove processing. The end mill has an advantage that automatic tool change can be easily performed, and is a tool suitable for grooving in an unmanned process by a machining center. On the other hand, the side cutter has a large load on the cutting edge of the chip, so there is a lot of chip blade loss and unmanned machining is impossible, but in a machine tool with a high rigidity structure and a high horsepower motor, it depends on other tools. Much more efficient grooving is possible.
[0003]
Chips used in conventional side cutters for grooving include a high-speed steel chip and a cemented carbide chip in terms of material. Many high-speed steel inserts are used for side cutters used for relatively simple grooving in small machine tools, and carbide inserts are used for side cutters used for grooving in medium and large machine tools. Is done. This type of carbide tip includes a brazing type and a throw-away type. Currently, a carbide throw-away tip is mainly used. In this carbide throw-away tip, the blade shape corresponding to chip countermeasures is devised, and various coatings are applied in order to improve the blade edge life.
[0004]
The side cutter for grooving has a larger body diameter compared to other cutters, and a low-speed range is used to obtain the same cutting speed as a small-diameter cutter. Therefore, one tooth of the reduction gear in the drive mechanism of the spindle The resistance against hitting increases, and particularly when the cutting edge is a negative type, a large resistance is generated.
[0005]
In addition, the groove processing by the side cutter has 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, although it varies somewhat depending on the groove depth. Since the side cutter is processed within this short 1/8 cutting length, the number of blades involved in the cutting is small, and the cutting process is intermittent cutting. In particular, a single blade is used at the start and end of cutting. Cutting results in a very loud intermittent sound.
[0006]
Therefore, in FIG. 9, among the conventional side cutter, showing the A key Sharureki angle of the cutting edge, the chip edge shape of the side cutter so-called Neganegataipu the radial rake angle are both set to negative (negative). This negative type blade type is inferior to the positive type in sharpness of the cutting edge, but has a feature that it can withstand severe cutting and has a long blade edge life.
[0007]
In FIG. 9, FIG. 9 (a) is a view showing the side cutter from the radial direction, and FIG. 9 (b) is a view showing the side cutter from the axial direction. 10 is a cutter body, and 12 is a throw-away tip. α is A key Sharureki angle that have been taken to the negative. As shown in FIG. 9A, chip pockets 11 are formed on the outer peripheral portion of the cutter body 10 at a predetermined interval. 12, a chip 13 mounting groove 13 and a chip locator 14 mounting groove 15 are formed adjacent to the chip pocket 11. In the tip 12, the tip constituting the left cutting edge 16a and the tip constituting the right cutting edge 16b are alternately distributed to the left and right and arranged in the circumferential direction. The tip 12 of FIG. 9 is a tip of a type in which four cutting blades are provided in one tip and the blade edge can be widened by one corner, and is fixed to the cutter body 10 by a tip pressing screw 16. Such a negative-type insert tip shape is compact and has a good insert economy, and is a generally adopted method, but has a large cutting resistance and tends to promote deterioration of the machine tool.
[0008]
Figure 10 is a side cutter having a A key Sharureki angle α of the cutting edge of the chip 20, the edge shape of the so-called Pojipojitaipu the radial rake angle β is set both to the positive (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 disposed on the back side of the chip 20. As shown in FIG. 10 (a), in the tip 20, the tip constituting the left cutting blade 20a and the tip constituting the right cutting blade 20b are alternately distributed to the left and right and arranged in the circumferential direction. It is the same as the negative type.
Such a positive / positive type tip edge shape has a shorter cutting edge life than the negative / negative type, but is excellent in sharpness.
[0009]
The negative type shown in FIG. 9 and the positive / positive type shown in FIG. 10 are properly used depending on the use environment and the material of the workpiece.
[0010]
[Problems to be solved by the invention]
The conventional side cutter has a large chip pocket 11 in order to enable deep groove processing. The number of chips 12 and 20 set is reduced by the amount of space for the chip pocket 11. In addition, since the cutting edge width of one edge of the insert 12 is relatively wide, the left cutting edge 12a and the right cutting edge 12b (or the cutting edge 20 in the case of the insert 20, the left cutting edge 20a and the right cutting edge 20b) overlap each other. The blade wrap width A is relatively large. This cutting edge wrap width A has the advantage of reducing the number of cutting blades in design and reducing the manufacturing cost of the cutter, but on the other hand, there are few cutting edges involved in cutting and inevitably becomes intermittent cutting and resistance. In addition, stable cutting may be difficult due to increased vibration.
[0011]
Further, as shown in FIG. 10, since it is provided with the A key Shall angle alpha, while the direction of the cutting resistance acting on the chip 20 is excluded to the outside from the cutter body 10, the backup of the locator 22 is weak structure Therefore, the locator 22 may be damaged when subjected to a large cutting resistance.
[0012]
Further, in the case of the positive / positive type, as shown in FIG. 10B, the lower half of the center of the chip 20 is clamped by being sandwiched between the wedge 21 and the locator 22 in view of the chip discharging property. For this reason, the locator 22 easily deforms into a square shape due to the cutting resistance acting on the chip 20, and if the cutting is continued as it is, a minute gap is formed between the back surface of the chip 20 and the front surface of the locator 22. Occurs, and the backup force of the chip is weakened, and the chip is damaged by receiving a large cutting resistance due to intermittent cutting. Once the chip breaks, the next cutting blade is damaged by a greater resistance, and this phenomenon is expanded in a chain.
[0013]
Accordingly, an object of the present invention is to provide a side cutter that eliminates the problems of the prior art, reduces cutting resistance, reduces the load on the cutting edge of the chip, extends the cutting edge life, and enables stable cutting. There is to do.
[0014]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention provides a grooving side cutter having a plurality of throw-away tips arranged in a circumferential direction on an outer peripheral portion of a cutter body. The tips for cutting and the tips for the right cutting edge are arranged at irregularly spaced intervals in the circumferential direction, and each tip is provided with a cutting edge extending in the thickness direction of the tip. The negative axial rake angle is set to at least 30 degrees, the side of the chip perpendicular to the thickness direction is received by the cutter body, and the side of the chip perpendicular to the width direction is received by the chip locator. fixed to the left and right cutting blade tip is made Gaisetsu blade tip and inner cutting edge tip of the chip, each paired Gaisetsu adjacent back and forth in the left and right cutting blade tip Cutting edge of different pitches in the use chip Naisetsu a blade for chips, the left Gaisetsu blade tip and right inner cutting edge for chips and Migigaisetsu blade tip and left inner cutting edge tip adjacent to the front and rear This is characterized in that the intervals are combined, and a large number of chips are arranged at uneven blade edge intervals.
[0015]
According to the present invention, since the main component force of the cutting resistance applied to the chip can be received at the cutter body, the load applied to the chip locator can be reduced, and the chip has a cutting edge in the chip thickness direction. Since it is provided so that the tip width direction is directed to the circumferential direction of the cutter body, the circumferential component of cutting resistance can be received from the width direction which is much stronger than the thickness direction. Therefore, the chip strength can be increased.
[0016]
Further, the cutting edge of the chip, cutting to when it is preferable to have a large A key Sharureki angle of 30 degrees or more, which from this, the cutting resistance increases gradually during cutting, to start cutting across blade cutting edge Since the maximum resistance is achieved, a large cutting force is not applied to the cutting edge instantaneously at the start of cutting, and the impact on the cutting edge can be mitigated, which prevents damage to the cutting edge as well as stable cutting, greatly extending the tool life. It becomes possible.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a side cutter according to the present invention will be described with reference to the accompanying drawings.
First Embodiment FIG. 1 shows a side cutter 30 according to a first embodiment of the present invention. FIG. 1A is a side view showing the arrangement of chips on the outer periphery of the cutter main body 32 of the side cutter 30, and FIG. 1B is a plan view of the side cutter 30.
[0018]
As shown in FIG. 1 (b), the cutter main body 30 is formed in a disc shape having a predetermined thickness, and is centered at the center for positioning coaxially with a tool arbor (not shown). A hole 33 is formed. The spindle of the machine tool is attached via a tool arbor and coupled to the spindle by a bolt inserted into the cutter clamp hole 34. The rotational torque of the main shaft is transmitted to the cutter body 30 via the torque transmission key 35.
[0019]
As shown in FIG. 1A, a plurality of grooves are formed in the circumferential direction in a staggered manner on the outer peripheral portion of the cutter body 30, and the following throw-away type chips are embedded in the grooves. It is attached.
[0020]
The throw-away tip includes a left blade tip and a right blade tip, which are sequentially arranged at predetermined intervals in the circumferential direction so as to be alternately distributed. The left blade tip 36 and the left inner blade tip 37 are paired with each other as the left blade tip, and the right outer blade tip 38 and the right blade tip are used as the right blade tip. The inner cutting edge tips 39 are paired with each other.
[0021]
2A is an enlarged view of a part of FIG. 1A, and FIG. 2B is an enlarged view of a part of FIG.
[0022]
On the left and right sides of the outer peripheral portion of the cutter body 32, a first tip mounting groove 41 for mounting a left outer cutting tip 36 and a right outer cutting tip 38 via a tip locator 40 is formed. . The second tip mounting groove 42 for mounting the left inner cutting tip 37 and the right inner cutting tip 39 via the tip locator 40 is continuous with the first tip mounting groove 41 in front of the cutter rotation direction. The chip pocket 45 is formed.
[0023]
In this embodiment, each chip has a rectangular piece shape, and the chip locator 40 has an L shape. The chip locator 40 can receive and restrain two side surfaces perpendicular to the width direction of the chip. Thus, it has the two constraining surfaces 40a and 40b which make a right angle. In a state where each chip 36 to 39 is combined with the chip locator 40 to form a rectangular shape as a whole and fit into the first chip mounting groove 41 and the second chip mounting groove 42, The cutter body 32 receives the widest vertical side (in the width direction), and the constraining surfaces 40a and 40b of the tip locator 40 receive the side surfaces perpendicular to the width direction. Each chip 36 to 39 is detachably fixed by a chip pressing screw 43, and the chip locator 40 is detachably fixed by a locator pressing screw 44.
[0024]
3A is a cross-sectional view taken along the line AA in FIG. 2B, showing a left outer cutting edge tip 36 and a left inner cutting edge tip 37. FIG. 3B is a cross-sectional view of FIG. It is BB sectional drawing in (b), and shows the chip | tip 38 for right outer cutting edges, and the chip | tip 39 for right inner cutting edges.
[0025]
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 through a tip locator 40, and the right outer cutting edge tip is also provided on the right side. 38 and a right inner cutting edge tip 39 are arranged through a tip locator 40 with a step.
[0026]
Thus, the cutting edges 46 are provided so as to extend in the chip thickness direction at the cutting edges of the chips 36 to 39 arranged on the left and right sides. In addition, the cutting edge of each of the tips 36 to 39 has a lateral clearance angle γ and a longitudinal clearance angle δ.
[0027]
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 main body 32 are set as follows. As shown in FIG. 2A, if the pitch between the left outer cutting edge tip 36 and the left inner cutting edge tip 37 adjacent to each other in the left blade is defined as pitch P1, the right edge adjacent to the right blade The cutting edge interval between the outer cutting edge tip 38 and the right inner cutting edge tip 39 is set to the same pitch P1. On the other hand, the interval of the blade edge between the adjacent left outer cutting edge tip 36 and the right inner cutting edge tip 39 is set to a pitch P2 (P2> P1) different from P1. In this way, by combining different pitches with respect to the cutting edge spacing between adjacent chips, the arrangement of a large number of cutting blades 46 is set to be unequal to suppress resonance during cutting and prevent cutting vibration. ing. In order to suppress cutting vibration and noise, it is desirable that the pitch between the cutting edges is small and the number of cutting blades is large. However, if the number of cutting blades is too large, the production cost of the cutter increases and the cutting resistance increases. Since the negative surface is larger than the positive surface, it is not preferable.
[0028]
In grooving by the side cutter 30, the blade involved in actual cutting while the cutter body 32 rotates is a cutting blade in the cutting length range shown in FIG. 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 main body 32. In order to maintain stable cutting, it is necessary that several cutting edges always enter the cutting length range of 1/8 of the outer peripheral length and participate in the cutting. The pitch is preferably such that there is at least one pair of left inner and outer cutting edge tips 36 and 37 and right inner and outer cutting edge chips 38 and 39 in the cutting length range.
[0029]
In the side cutter 30 according to the present invention, each of the tips 36 to 39 is a throw-away tip having the same cutting edge configuration. The shape of the throw-away tip 50 as a single unit is shown in detail in FIG.
[0030]
As shown in FIG. 4, the tip body 50 of one throw-away tip has cutting edges 46 formed at four corners thereof so that the tip can be used with its front and back being changed. In the center of the chip body, a chip set hole 49 for inserting the above-described chip pressing screw 43 is formed. In this case, the cutting edge 46 provided in the thickness direction at each corner, the negative of A key Sharureki angle α is set at a large angle. The A key Sharureki angle α is preferably 30 ° or more. Reference numeral 52 denotes a flat width following the cutting blade 46, and secures the side surface of the cutting blade 46 that comes into close contact with the chip locator 40 when the chip is replaced.
[0031]
FIG. 5 is a diagram showing a CC cross section in FIG. 4. An R squeeze surface 48 is formed at a corner portion of the chip body 50. Cutting edge 46, rake angle both in a predetermined A key Sharureki angle α mentioned above forms a blade shape by R rake face 48 theta is set. Further, a land width 51 is provided at the tip of the cutting blade 46 for protection of the cutting edge, and both end portions of the cutting blade 46 are R-shaped in order to increase the blade shape strength.
Next, the cutting action of the side cutter configured as described above will be described.
In FIG. 1, 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. Chips shaved with the left inner cutting edge tip 37 and the right inner cutting edge tip 39 accumulate in the tip pocket 45, and the chips shaved with the left outer cutting edge tip 36 and the right outer cutting edge tip 38 are The left inner cutting edge tip 37 and the right inner cutting edge tip 39 accumulate in a gap on the side.
[0032]
Left and right inner and outer edge of the chip 36 to 39, because it has a large A key Sharureki angle negative α the cutting edge, the direction of action of the cutting force F, as shown in FIG. 2 (a), the cutter body portion 32 side It will turn. When the cutting force F is divided into an axial component force Fa and a circumferential component force Fb, the cutter body portion 32 can receive the axial component force Fa of the cutting force F applied to the chips 36 to 39. The load applied to the tip locator 40 can be reduced, and the tip locator 40 can be prevented from being damaged.
[0033]
Further, since the chips 36 to 39 are provided so that the cutting edge 46 is provided in the chip thickness direction and the chip width direction is directed to the circumferential direction of the cutter main body 32, the circumferential force component Fb of the cutting force F is provided. Can be received from the width direction, which is much stronger than the thickness direction, so that the chip strength can be enhanced. Moreover, the chip 36 to by taking a cutting edge structure 39 in the thickness direction, it is assumed cutting width of the cutting edge 46 is narrow, the on that much burden on the cutting edge 46 is reduced, a large A key Sharureki angle α Since the cutting width is widened and the resistance is dispersed, the life of the cutting edge can be improved.
[0034]
Next, a description will be given of the cutting action by making the cutting edge of the chip into a reasonable cutting edge shape.
FIG. 6 is a view showing the mechanism of the cutting action of the chip 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. The cutting edge 46 is large because it has a A key Sharureki angle alpha, gradually increasing the range of the blade cutting a gradually workpiece from one end to the other end of the cutting edge 46. Along with this, the cutting resistance gradually increases, and the cutting resistance becomes maximum when the entire cutting edge 46 hits the workpiece and starts cutting with the entire cutting edge 46. In this way, the cutting resistance gradually increases, and the cutting resistance is maximized when the cutting of the entire cutting edge 46 starts. Therefore, as the cutting starts, a large cutting resistance is instantaneously applied to the cutting edge. It will not load. Therefore, the cutting vibration can be reduced and the impact on the cutting edge can be mitigated, so that the cutting edge can be prevented from being damaged and the tool life can be greatly extended.
[0035]
Further, upon setting a large A key Sharureki angle of the cutting edge, because it sets the rake angle theta, there is an advantage that the effect of reducing the cutting resistance exerted on the cutting edge is doubled. This is because by providing the squeeze angle θ, the cutting edge not only pushes the work piece but also pulls it, and the cutting resistance is further reduced.
[0036]
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, the four tips 36 to 39 forming the inner blade and the outer blade on the left and right are arranged in the circumferential direction as a set, whereas in the second embodiment, the left blade The left cutting edge tip 60 forming the right blade and the right cutting edge tip 60 are arranged in the circumferential direction as a set. Such a side cutter according to the second embodiment is applied to groove processing in which the groove processing width W is relatively narrow, and the thicknesses of the left cutting edge tip 60 and the right cutting edge processing tip 61, respectively. The processing width W of the groove is covered. The single chip, have been used the same chip as the first embodiment, a large negative for A key Sharureki angle α is set to the cutting edge 46.
[0037]
Further, the pitch interval between the left cutting edge tip 60 and the right cutting edge chip 61 that are adjacent to each other in the front-rear direction is not constant but is set to be unequal. In this case, the pitch interval P1 between the right cutting edge tip 60 and the left cutting edge tip 61 adjacent on the front side and the pitch interval P2 between the left cutting edge tip 61 adjacent on the rear side are as follows. Is different. Thereby, the resonance which generate | occur | produces during cutting is suppressed, and it enables it to perform stable cutting.
[0038]
Third Embodiment FIG. 8 is a view showing a throwaway tip of a side cutter tool according to a third embodiment of the present invention from four directions.
This slow Au E Lee chips, cutting edge 70 formed on the cutting edge is formed in the thickness direction of the chip, in the range of large A key blade shape Sharureki angle α and rake angle θ is set to the first embodiment The tip is the same as that of the embodiment, except that a convex blade shape that curves convexly is employed as the cutting blade 70 and that the squeeze surface 71 that forms the squeeze angle θ is chamfered. As shown in FIG. 4, the straight blade-shaped cutting blade 46 may curl in a spiral shape to increase the rigidity, resulting in a large cutting resistance. Since the shape does not curl and becomes an arc shape, rigidity is lost. Moreover, the separation | spacing from the cutting blade becomes favorable by taking the space of the squeeze surface 71 large.
[0039]
Furthermore, the chip body is provided separately with a nick 72A and a nick 72B, and these are alternately attached to the cutter body 32, whereby the chips can be made smaller and the chips can be discharged more favorably. It is effective in preventing clogging of chip pockets and protecting the finished surface of the groove.
[0040]
【The invention's effect】
As is apparent from the above description, according to the present invention, the cutting force is reduced and a large cutting force is not momentarily applied to the cutting edge of the chip, so that the cutting edge life can be greatly extended. In addition, the load on the cutting edge and the tip locator can be reduced, and stable and smooth high-efficiency cutting can be achieved even with intermittent cutting of the side cutter. Therefore, the deep groove processing by the conventional side cutter, which could only be performed by a machine tool having high rigidity, can be realized with higher productivity and more economically by a machine tool having average rigidity.
[Brief description of the drawings]
1A and 1B are diagrams showing a first embodiment of a side cutter according to the present invention, in which FIG. 1A is a side view of a cutter body, and FIG. 1B 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 view showing a cross section AA in FIG. 2B, and FIG. 3B is a view showing a BB cross section in FIG. 2B.
FIG. 4 is a perspective view of a single chip according to the first embodiment.
FIG. 5 is a view showing a CC cross section in FIG. 4;
FIG. 6 is a view for explaining a cutting mechanism of a side cutter according to the present invention.
FIG. 7 is a diagram showing a second embodiment of a side cutter according to the present invention.
FIG. 8 is a view showing chips according to a third embodiment of the side cutter according to the present invention from four directions, respectively.
FIG. 9 is a view showing a side cutter of a conventional negative-type blade edge configuration.
FIG. 10 is a diagram showing a side cutter having a conventional positive / positive type blade edge configuration.
[Explanation of symbols]
30 Side cutter 32 cutter body portion 36 left Gaisetsu blade tip 37 left inner cutting edge tip 38 Migigaisetsu edge chip 39 right inner cutting edge tip 40 tip locator 45 chip pocket 46 cutting 48 rake face α A key Charrake angle θ Squee angle

Claims (3)

In the side cutter for grooving having a plurality of throwaway type chips arranged in the circumferential direction on the outer peripheral portion of the cutter body,
A plurality of left cutting edge tips and right cutting edge tips are arranged in the cutter body portion at uneven cutting edge intervals in the circumferential direction, and each cutting edge has a cutting edge in which the cutting edge extends. The tip has a negative axial rake angle set to at least 30 degrees, the side surface perpendicular to the thickness direction of the tip is received by the cutter body, and the side surface perpendicular to the width direction is the tip locator. the chip is fixed to the cutter body so as to receive at the left and right cutting blade tip is made Gaisetsu blade tip and inner cutting edge tip of the chip, each paired back and forth in the left and right cutting blade tip Adjacent outer cutting tips and inner cutting tips, front and rear left outer cutting tips and right inner cutting tips, and right outer cutting tips and left inner cutting tips different blade of in pitch Combining interval, side cutter, characterized in that an array of a large number of chips at the cutting edge spacing of unequal distribution.   The side cutter according to claim 1, wherein a squeeze angle is further set at a cutting edge of the front tip.   The side cutter according to claim 1 or 2, wherein a cutting edge of the tip has a convex cutting edge that curves in a convex shape.

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