JP2007216384A - Deep hole cutting method using deep hole cutting drill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deep hole cutting method, remarkably improving cutting power. <P>SOLUTION: In the case where a core with a diameter proportional to a core drop amount ε of a knife edge part 2 of a drill head 1 is generated and formed in a non-cutting zone, when the spiral moving angle of a contact point between the knife edge part 2 and the core in proportion to the linear feed s of the knife edge part 2 spirally moving is θ, deep hole cutting is performed so that the core drop amount εand the feed s are set within the range expressed by a formula: ε/s≥1/(2π*tanθ). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention particularly relates to a deep hole cutting method using a deep hole cutting drill.

  When this type of tip is attached to the drill head in the radial direction with respect to the rotational axis, the tip of the tip naturally has to be accurately positioned in order to cut to the center of the workpiece. I have to pass. However, since the cutting speed at the center of the drill is theoretically zero, the cutting edge of this part is loaded with thrust resistance, so-called chisel edge, which is the part where the cutting force does not work. This is one of the reasons why we cannot improve our ability.

  In order to avoid this, as shown in FIGS. 10 and 11, the tip 20 that is attached to the tip of the drill head 1 in the radial direction has a center 21 whose blade edge 21 passes through the rotational axis O of the drill head 1. The chip breaker 23 attached to the rake face 22 of the cutting edge portion 21 is also located at the down-centered position, that is, attached to the cutting edge 22 in the counterclockwise direction with respect to the line CL. As shown in FIGS. 10 and 11, a non-cutting zone 24 corresponding to the center down amount ε × 2 is provided between the portion 21 and the rotation axis O, and the rotation axis O side is overlaid as shown in FIG. By cutting the workpiece W with the blade edge portion 21 having the lapped inner cutting edge angle β, the core C that is not cut remains in the non-cutting zone 24 during the cutting process, and this is broken by the chip breaker 23 during the cutting process. Indicated by As the folded taken is subdivided, a technology for better discharged from the discharge hole of the drill head 1 together with the cutting chips is proposed by the applicant, is currently pending.

  According to this, the cutting edge portion 21 is not located on the rotation axis O of the drill head 1 and the so-called chisel edge portion does not exist, so that the cutting force can be significantly increased as compared with the prior art. As shown in FIG. 11, the portion of the blade edge portion 21 that contacts the core (zone A and the surrounding zone B) is close to the chisel edge (rotation axis O), and therefore receives a large cutting resistance, and has a long period of time. There was a possibility that chipping occurred during use and the cutting edge part of the zone A or B part was broken.

  An object of the present invention is to propose a deep hole cutting method using a deep hole cutting drill that has completely eliminated the above-mentioned difficulties and has succeeded in dramatically improving the cutting ability.

の範囲に、前記芯下がり量εと前記送り量ｓが設定されるようにして切削するようにした深孔切削方法に係る。 In order to solve the above-mentioned problem, the invention according to claim 1 is provided with a cutting edge portion 2 on the tip portion of the drill head 1 and a scooping surface 3 of the cutting edge portion 2 if the reference numerals shown in the embodiment are attached. In the deep hole cutting drill in which the cutting tip 5 on which the chip breaker 4 is formed is attached to the rotation axis O of the drill head 1 in the radial direction, the inner cutting edge angle of the cutting tip 5 The cutting edge portion 2 having β is rotated from the center line CL (axis passing through the rotation axis O) in the counter-rotating direction, that is, the position of the center downward with respect to the center line CL and the center line CL. The tip breaker 4 provided on the rake face 3 of the cutting edge portion 2 is also provided with a taper surface 2a overlapping between the position raised in the direction, that is, the center rise position with respect to the center line. The position raised in the rotation direction from the line CL, that is, When a core having a diameter proportional to the amount of core lowering ε of the cutting edge portion is generated and formed in the non-cutting zone by using a deep hole cutting drill provided at a position where the core is lifted with respect to the core line CL, When the spiral movement angle at which the contact between the blade edge portion and the core moves in a spiral manner in proportion to the linear feed amount s of the blade edge portion is θ,

In this range, the deep hole cutting method is performed such that the center fall amount ε and the feed amount s are set.

  The invention according to claim 2 is the deep hole cutting drill according to claim 1, wherein the taper angle γ of the taper surface 2 a of the cutting edge portion 2 is 15 to 45 ° with respect to the rotation axis O. Relates to a deep hole cutting method using

  The invention according to claim 3 relates to a deep hole cutting method using the deep hole cutting drill according to claim 2, wherein the tapered surface 2a of the cutting edge portion 2 is formed by honing.

  The invention according to claim 4 is characterized in that the amount L of overlap of the cutting edge portion 2 is 0.1 to 0.4 mm. The depth using the deep hole cutting drill according to any one of claims 1 to 3. The present invention relates to a hole cutting method.

  Moreover, the invention which concerns on Claim 5 uses the drill for deep hole cutting in any one of Claims 1-4 in which the internal cutting-blade angle (beta) of the said blade edge | tip part 2 is formed in the range of 15 degrees-60 degrees. Related to the deep hole cutting method.

  According to the deep hole cutting method using the deep hole cutting drill of the invention according to claim 1, the cutting edge portion having the inner cutting edge angle of the cutting tip attached to the tip portion of the drill head has its center line. The position lowered in the anti-rotation direction from the (axis passing through the rotation axis), that is, the position of the center down with respect to the center line, and the position raised in the rotation direction from the center line, ie, the position of the center up with respect to the center line Since the blade tip portion of the portion in contact with the core is a tapered surface, the blade edge strength can be sufficiently provided, and the taper surface can be sufficiently provided. The cutting action and the crushing action as well as the sum of the crushing action and the inner cutting edge angle can be expected to provide an efficient cutting action. The taper face is formed and formed by the taper face itself. And is subdivided by the chip breaker provided on Suiku surface, the core can be satisfactorily carried out from the discharge hole of the drill head together with the chips.

  Furthermore, during the rotation of the drill head, the cutting operation is not necessarily performed while accurately maintaining the center of rotation, a slight runout occurs due to the action of external force, etc., and the cutting edge part sandwiches the rotation axis, There may be a slight deviation between the center-up state and the center-down state, but even in this case, the deviation is absorbed between the widths of the tapered surface of the blade edge, and breakage such as chipping of the blade edge can occur. It can be prevented as much as possible.

の範囲に、前記芯下がり量εと前記送り量ｓが設定されるようにして深孔切削するようにしてなるため、所謂切削途上でドリルヘッドの回転軸心側に取着される内切刃角を有するチップが、その切削作業途上で被削材との干渉によりチップの折損等の発生することはない。 According to the present invention, particularly when a core having a diameter proportional to the amount of core drop ε of the cutting edge portion is formed and formed in the non-cutting zone, the cutting edge is proportional to the linear feed amount s of the cutting edge portion. When the spiral movement angle at which the contact between the part and the core moves spirally is θ,

Since the deep hole cutting is performed so that the center down amount ε and the feed amount s are set in the range of the inner cutting edge that is attached to the rotary shaft side of the drill head during the so-called cutting process The tip having a corner does not break the tip due to interference with the work material during the cutting operation.

  According to the invention of claim 2, the taper angle of the taper surface of the blade edge portion is preferably 15 to 45 ° with respect to the rotation axis, and in the case of 15 ° or less, the blade edge The strength of the part becomes insufficient, and there is a risk of being affected by the chisel edge with less core formation. When the angle is 45 ° or more, the crushing action increases with respect to the cutting action of the cutting edge, resulting in cutting. The resistance increases and the cutting force becomes insufficient.

  According to the invention of claim 3, the tapered surface of the blade edge portion is preferably formed by honing, and the edge of the blade edge can be satisfactorily sharpened by this honing and good cutting action. Can contribute.

  Moreover, according to the invention which concerns on Claim 4, it is preferable that the amount of overlap of a blade edge | tip part is 0.1-0.4mm, and when 0.1 mm or less, blade edge strength is fully ensured. In addition, the generation of the core is insufficient and the cutting efficiency cannot be increased. Even in the case of 0.4 mm or more, the generation of the core is sufficiently performed and the cutting efficiency can be increased, but the crushing action is increased with respect to the cutting action of the cutting edge part, and as a result, the cutting resistance is reduced. There is a risk that the cutting force will be slightly insufficient.

  Moreover, according to the invention which concerns on Claim 5, it is preferable that the internal cutting-blade angle of a blade edge part is formed in the range of 15 degrees-60 degrees, and when it is 15 degrees or less, it is rather than the cutting force of the blade edge part 2. The crushing action becomes large and it is difficult to increase the cutting force, and when it is 60 ° or more, it is difficult to increase the cutting strength of the blade edge portion 2.

  1 and 2 show a state in which a tip 5 according to an embodiment of the present invention is attached to a tip portion of a drill head 1, and tips 5a and 5b are respectively provided at a central portion side, an intermediate portion side and an outer peripheral portion side. And 5c are attached to the tip of the drill head 1 by bolts 6 in the radial direction. Of these, the present invention particularly relates to the tip 5a attached to the center side, and the cutting edge portion 2 having the inner cutting edge angle β of the tip 5a is attached to be overlapped to the rotation axis O side. Yes.

  1 and 2, chip discharge holes 7 and 8 are formed in the drill head 1, and a guide pad 9 is fixed to the outer peripheral surface side of the drill head 1. The tip 5 shown in FIGS. 1 and 2 relates to a so-called slow-away tip that is detachably attached to the drill head 1 with a bolt 6, but of course a brazed tip may be used.

  As shown in FIGS. 3 and 4, the tip 5 a attached to the center portion side of the drill head 1 includes a portion having a cutting edge portion 2 having an outer cutting edge angle α and a portion having an inner cutting edge angle β. Among them, the blade edge portion 2 having the inner cutting edge angle β is attached so as to overlap the center line CL passing through the rotation axis O in the radial direction.

  As shown in FIGS. 5 and 6, the blade edge portion 2 has a position lowered in the counter-rotating direction from its center line (axis passing through the rotation axis), that is, a position 2A that is centered downward with respect to the center line CL. , A position 3 that rises in the rotational direction from above the center line CL, that is, a taper surface 2a that overlaps with the center line 2B from the center line 2B, and the scooping surface 3 of the cutting edge 2 Further, the chip breaker 4 provided on the scooping surface 3 is provided at a position rising in the rotational direction from the center line CL, that is, at positions 3a and 4a that are centered up with respect to the center line.

  The taper angle γ of the taper surface 2a with respect to the rotational axis O is set to 15 ° to 45 °, and the position from the core lowering position 2A of the rotational axis O of the blade edge portion 2 to the position 2B of the core rising. The overlap amount L is set in a range of 0.1 to 0.3 mm.

  Therefore, when the overlap amount L of the blade edge portion 2 is 0.3 mm and the taper angle γ is 30 °, the width p1 of the tapered surface 2a is 0.6 mm.

  The tapered surface 2a is formed by honing and naturally forms a cutting surface.

  FIG. 6 shows a phenomenon of cutting by the cutting edge part 2 and, as shown in FIG. 5, the overlap amount L of the cutting edge part 2 is 0.3 mm and the taper angle γ is 30 °. When the width p1 of the taper surface 2a of No. 2 is 0.6 mm and the rotation axis O is overlapped with the width center portion t of the taper surface 2a, the width p2 of the portion in charge of cutting is the center down position It is 0.3 mm on the 2A side, becomes an obtuse angle with respect to the flank 11, and ensures the strength of the core lowering position 2 </ b> A of the cutting edge portion 2.

  Accordingly, as shown in FIG. 7, the work material W is cut as shown in the portion p2 from the core lowering position 2A of the blade edge portion 2 to the width center portion t, and some cores C are generated and formed during the cutting. At the same time, the core C is broken by the taper surface 2a and subdivided by the chip breaker 4 formed on the scooping surface 3 and discharged.

  Since the work piece is cut by the cutting edge portion 2 formed on the tapered surface 2a in this way, a slight crushing action works together with the cutting action. This is the inner cutting edge angle β of the cutting edge portion 2. Efficient cutting action can be expected by taking a large value. Further, during the rotation of the drill head 1, the cutting operation is not always performed while accurately maintaining the rotation center O, and a slight runout occurs due to the action of an external force or the like, so that the cutting edge portion 2 has a rotational axis O. Although there is a case where it is slightly biased between the up-centered state and the center-down state, the tip is absorbed by the width of the tapered surface 2a of the blade edge portion 2 and the chipping of the blade edge portion 2 is performed. The occurrence of breakage such as can be prevented as much as possible.

  By the way, as described above, the core C having the radius ε [mm] (FIGS. 6 and 7) as a radius is generated and formed by the blade edge portion 2. Depending on the amount ε and the feed amount s of the cutting edge 2, interference may occur with the work material. Therefore, the center down amount ε and the feed amount s of the cutting edge 2 are in the condition of the region where no interference occurs. Must be set.

となる。

が成り立つ。
ゆえに、内切刃角βを有する刃先部２の被削材に対する干渉が起こらない領域は、

と表すことができる。
即ち、刃先部２の芯下がり量εと送り量ｓは、

と同じか又はそれ以上の領域に設定する必要がある。 When this is expressed by a calculation formula, in FIG. 8 and FIG. 9, when the core C having the radius of the core down amount ε [mm] is generated, the point P where the core C and the blade edge portion 2 are in contact is the feed amount s. Moves spirally with [mm / rev]. If the angle formed by the circumference and the point P at this time is θ [°], the diagrams shown in FIGS.

It becomes.

Holds.
Therefore, the region where the cutting edge portion 2 having the inner cutting edge angle β does not interfere with the work material is:

It can be expressed as.
That is, the amount of core drop ε and the feed amount s of the blade edge part 2 are as follows.

Must be set to the same or larger area.

  As described above, in the present invention, the cutting edge portion 2 having the inner cutting edge angle β of the cutting tip 5 attached to the tip portion of the drill head 1 has its center line CL (the axis passing through the rotation axis O). ) In the counter-rotating direction, that is, a position 2A that is centered down with respect to the center line CL, and a position that is in the direction of rotation from above the center line CL, that is, a position 2B that is centered up with respect to the center line CL. Since the blade edge portion 2 of the portion in contact with the core C is a tapered surface 2a by being overlapped in a tapered surface 2a shape between them, the blade edge strength can be sufficiently provided, and The tapered surface 2a can be expected to have an efficient cutting action by taking the sum of the crushing action as well as the cutting action, and by taking a larger inner cutting edge angle β, and the core C formed and formed by the tapered face 2a is , Taper The core C is broken by the surface 2a itself and subdivided by the chip breaker 4 provided on the scooping surface 3, so that the core C can be carried out better than the discharge hole of the drill head 1 together with the chips.

  In this case, the taper angle γ of the taper surface 2a of the blade edge portion 2 is preferably 15 to 45 ° with respect to the rotation axis O. There is a problem in strength, and there is a risk that the generation of the core C is small and the influence of the chisel edge may be exerted. Increases and the cutting force becomes insufficient.

  Moreover, since the taper surface 2a of the blade edge | tip part 2 is formed by honing processing, the blade edge | tip part 2 can be sharpened well and it can contribute to cutting action favorably.

  Furthermore, the overlapping amount L (FIGS. 5 and 6) of the blade edge portion 2 is preferably 0.1 to 0.4 mm, and when the edge length is 0.1 mm or less, the blade edge strength is sufficiently ensured. In addition, the generation of the core C is insufficient and the cutting efficiency cannot be increased. Even in the case of 0.4 mm or more, the generation of the core C is sufficiently performed and the cutting efficiency can be increased, but the crushing action is increased with respect to the cutting action of the cutting edge portion 2, resulting in cutting. There is a possibility that the cutting force is slightly insufficient due to an increase in resistance.

  Furthermore, the inner cutting edge angle β (FIG. 3) of the blade edge portion 2 is preferably formed in the range of 15 ° to 60 °, and when it is 15 ° or less, the crushing action is greater than the cutting force of the blade edge portion 2. Increases, it is difficult to increase the cutting force, and when it is 60 ° or more, it is difficult to increase the cutting strength of the blade edge portion 2.

It is a front view of the drill for deep hole cutting which concerns on one Embodiment of this invention. It is the same top view. It is an enlarged view of the cutting tip which is the principal part. It is the same top view. FIG. 4 is a cross-sectional view taken along line AA in FIG. 3. It is an enlarged plan view which shows the attachment position to the drill head of the chip | tip of the principal part. It is effect | action explanatory drawing which shows the cutting state which cuts a work material with the chip | tip for cutting of one Embodiment of this invention. It is explanatory drawing explaining the effect | action of the principal part. It is explanatory drawing for demonstrating the effect | action of the principal part. It is explanatory drawing which shows the cutting state which cuts a cut material with the cutting tip of a prior art. It is a top view of the chip. It is a front view of the chip.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drill head 2 Cutting edge part 2a Tapered surface 3 Sloping surface 4 Tip breaker 5 Cutting tip O Rotating shaft center β Inner cutting edge angle CL Center line γ Taper angle L Overlapping amount C core

Claims (5)

Deep hole cutting in which a cutting tip having a cutting edge formed on the tip of the drill head and a chip breaker on the cutting surface of the cutting edge is attached to the rotation axis of the drill head in the radial direction. In the drill for cutting, the cutting edge portion having the inner cutting edge angle of the cutting tip is a position lowered in the counter-rotating direction from the center line (axis passing through the rotation axis), that is, a position of the core lowering with respect to the center line, A chip breaker provided on the rake face of the blade edge portion, which is provided in a taper surface overlapping with the position raised in the rotational direction from the center line, i.e., the center up position with respect to the center line, Using a deep hole cutting drill provided at a position that is raised in the rotational direction from the center line, that is, at a position that is centered up with respect to the center line, a core having a diameter proportional to the amount of core lowering ε of the cutting edge is not cut. Formation formed in the zone Case, when the contact point between the blade tip portion and the core in proportion to the linear feed amount s of the blade tip part has a spiral moving angle which moves helically θ that,

A deep hole cutting method in which cutting is performed such that the core drop amount ε and the feed amount s are set in a range of.   2. The deep hole cutting method using the deep hole cutting drill according to claim 1, wherein the taper angle of the tapered surface of the blade edge portion is formed to be 15 to 45 ° with respect to the rotation axis.   The deep hole cutting method using the deep hole cutting drill according to claim 2, wherein the tapered surface of the cutting edge portion is formed by honing.   The deep hole cutting method using the deep hole cutting drill according to any one of claims 1 to 3, wherein an amount of overlap of the cutting edge portion is 0.1 to 0.4 mm.   The deep hole cutting method using the deep hole cutting drill according to any one of claims 1 to 4, wherein an inner cutting edge angle of the cutting edge portion is formed in a range of 15 ° to 60 °.

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