JP6543956B2 - Deep Hole Drilling Tool - Google Patents

Description

  The present invention, for example, is attached to the tip of a boring bar used for drilling oil and the like, and the cutting oil supplied from the gap between the tool body and the processed deep hole in the workpiece together with the cutting waste is the tool body and bow link The present invention relates to a deep hole processing tip tool (borink head) which passes through the inside of a bar and is discharged to the rear end side.

In order to precisely perform deep hole machining by the so-called BTA method using the deep drilling tip tool as described above, the tip surface of the tool is placed 90 degrees in the direction to receive the cutting force of the blade provided on the tip surface. A deep hole machining tool has been proposed in which three guide pads are arranged at equal intervals in each case (see, for example, Patent Document 1).
However, in the deep hole processing tool described in Patent Document 1, the processing tool and the boring bar generate unstable vibration during deep hole processing, and as a result, the cutting amount of the workpiece changes, and the blade portion In some cases, the cross section of the formed deep hole becomes triangular or pentagonal due to fluctuations in contact force between the guide pad and the workpiece.

Furthermore, in order to solve the problems caused by the deep hole processing tool described in Patent Document 1, the positions of the three guide portions disposed on the tip surface side of the tip tool with respect to the rotation center of the tip surface of the tip tool When the position of the cutting edge of the blade portion is 0, the first guide portion is rotated 180 ° ± 10 ° to a position rotated 90 ° ± 10 ° in the direction to receive the cutting force of the blade portion. A guide portion arrangement structure and a guide portion arrangement method for a deep hole processing tip tool in which the third guide portion is arranged at a position where the second guide portion is rotated 181 degrees to 220 degrees have been proposed (for example, Patent Document 2).
According to the guide portion arrangement structure of the deep hole processing tip tool described in Patent Document 2, the unstable vibration due to the tip tool and the boring bar is slightly reduced during deep hole processing, but the formed depth is formed In some cases, the cross section of the hole may be triangular or pentagonal.

Japanese Utility Model Application Publication No. 5-53812 (pages 1 to 3, FIGS. 1 to 7) Patent No. 4951788 (pages 1 to 24, FIGS. 1 to 13)

  The present invention solves the problems described in the background art, can significantly reduce the unstable vibration due to the tip tool and boring bar during deep hole processing, and the cross section of the deep hole formed in the workpiece It is an object of the present invention to provide a deep hole processing tip tool which can be approximated closely to a perfect circle.

Means for Solving the Problems and Effects of the Invention

In order to solve the above-mentioned subject, the present invention is conceived to arrange four guide pads at appropriate positions on the tip surface side of the tip tool.
That is, the deep hole processing tip tool (claim 1) of the present invention is attached to the tip of the boring bar, and the cutting oil supplied from the gap between the tool body and the processed deep hole in the workpiece together with the cutting debris A deep hole processing tip tool which passes through the inside of the tool body and the bow link bar and discharges to the rear end side, the tool body having a cylindrical shape as a whole, and a cutting tool attached to the tip surface of the tool body The cutting edge from the center of rotation of the tip surface of the tool body, including a blade, and first to fourth guide pads disposed across the periphery of the tip surface of the tool body and the circumferential surface of the tool body When the position of the imaginary radial line passing through the blade surface is 0 degrees, the first guide pad is rotated 180 degrees ± 90 degrees at a position rotated 90 degrees ± 10 degrees in the direction to receive the cutting force of the cutting edge Position the second guide pad at the position rotated 10 degrees And the fourth guide pad is disposed at a position obtained by rotating the third guide pad at a position rotated by 220 ° ± 10 ° and a position obtained by rotating the third guide pad by 270 ° ± 10 °.

According to this, when the position of the imaginary radial line where the first, second and fourth guide pads pass the blade surface of the cutting blade from the rotation center of the tip surface is set to 0 degree, The following effects (1) to (4) can be achieved by arranging the third guide pads at positions separated by about 90 degrees in order to receive the cutting force and arranging the third guide pads at positions separated by about 220 degrees. It becomes possible.
(1) During deep hole processing, even if the first to third guide pads contact the inner wall surface of the processed deep hole and receive an outward force, the fourth guide pad receives a force toward the rotation center. Therefore, as a whole, the balance is maintained, and the cross section of the deep hole formed in the workpiece is unlikely to be triangular, and approximate to a perfect circle.
(2) During deep hole processing, the third and fourth guide pads face the center of rotation even if the first and second guide pads contact the inner wall surface of the processed deep hole and receive an outward force. Since the force is received, the balance as a whole is achieved, and the cross section of the deep hole formed in the workpiece is unlikely to be a pentagonal shape, and becomes close to a perfect circle shape.
(3) By combining the above (1) and (2), unstable vibration during deep hole machining can be significantly reduced.
(4) By the above (1) to (3), it becomes possible to form a cross section similar to a circular cross section to the workpiece and to form a straight deep hole along the axial direction with certainty.

The tool body is made of, for example, steel for machine structural use (SC steel type) or the like, and a through hole for discharging cutting oil and chips between the tip end face and the rear end face penetrates along the axial direction. doing.
Further, the cutting blade may have, for example, a single elongated tip made of cemented carbide (WC), or when the diameter of the tip surface and the inner diameter of the deep hole to be processed are relatively large. As described later, three or more chips may be linearly arranged at positions including the center and the periphery of the tip surface along the radial direction of the tip surface.
Further, the position of the cutting edge is a side along a radial direction of a blade surface for cutting a workpiece.
Furthermore, the guide pad is made of, for example, cemented carbide (WC), and is provided in a recessed groove formed along the axial direction and extending between the periphery of the tip surface of the tool body and the circumferential surface of the tool body. For example, a plurality of bolts or the like are inserted so that a plate-shaped base is inserted, and a curved surface similar in shape to the circumferential surface of the tool body adjacent on both sides in the circumferential direction protrudes outward from the circumferential surface. Fixed by
In addition, a work material in which a deep hole is formed by the boring bar and the deep hole processing tip is, for example, a circumferential surface (surface) side in order to obtain a long pipe used for drilling of oil or the like. A long (for example, about 1000 cm) round bar made of austenitic stainless steel hardened by warm forging etc. may be mentioned.

Further, in the present invention, when the position of the cutting edge is 0 degree from the rotation center of the tip end surface of the tool main body, the third guide pad receives the cutting force of the cutting edge 221 to 221. Also included is a deep drilling tip tool (Claim 2) disposed at a position rotated by 230 degrees.
According to this, it becomes easier to balance the overall forces received by the first to fourth guide pads described above, so that the effects (1) to (4) can be reliably obtained.

Furthermore, in the present invention, at the tip end surface of the tool main body, at a position excluding the cutting edge, one or more openings communicating with the through holes for discharging the cutting oil and cuttings are located. Also, a deep drilling tip tool (claim 3) is included.
According to this, the cutting oil forcedly fed from the gap between the deep hole formed in the workpiece and the outer peripheral surface of the tool main body together with the cutting waste, the singular or plural opened in the tip end surface of the tool main body The boring bar can be fed to the through hole communicated from the opening of the boring bar and reliably discharged from the inside of the boring bar to the base side thereof. Therefore, it is possible to prevent a situation where the roundness of the deep hole in the effect (4) is impaired.

In addition, in the present invention, the cutting blade includes a central tip including the rotation center of the tip surface of the tool body, an outer circumferential tip partially protruding outward from the periphery of the tip surface, and the outer circumferential side. The tip is formed at an intermediate position on the opposite side of the center of rotation of the tip surface and is composed of the tips and an intermediate tip disposed linearly along the diameter line. A tip tool (claim 4) is also included.
According to this, even when the diameter of the tool main body is relatively large (for example, about 60 mm), the workpiece can be processed in the radial direction along the periphery from the rotation center in the tip end face of the main body. Deep hole processing can be reliably performed by the rotation of the entire tip surface.
In addition, the cutting resistance can be reduced as compared with a cutting blade consisting of a single tip, and a plurality of (two or more) openings of through holes through which the cutting oil passes along with the cutting waste to the rear end side of the tool body As a result, the cutting oil and chips can be recovered smoothly (effect (5)).

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of one embodiment of a deep hole drilling tip tool according to the present invention. (A) is a side view along the arrow A direction in FIG. 1, (B) is a side view along the arrow B direction in FIG. Schematic which shows the use condition of the said tip tool for deep hole processing. The graph which shows the roundness of the deep hole formed by the tip tool of an example and a comparative example. The graph which shows the displacement amount with respect to the frequency in the tip tool of an Example and a comparative example. The graph which shows the eccentric amount accompanying the processing length by the tip tool of an Example and a comparative example. The top view which shows the tip tool for deep hole processing of a different form. (A) is a side view along the arrow A direction in FIG. 7, (B) is a side view along the arrow B direction in FIG. 7.

Hereinafter, modes for carrying out the present invention will be described.
FIG. 1 is a plan view showing one embodiment of a deep hole drilling tip tool 1a according to the present invention, FIG. 2 (A) is a side view along the direction of arrow A in FIG. 1, and FIG. FIG. 5 is a side view along the arrow B direction in FIG.
As shown in FIG. 1, FIG. 2 (A) and FIG. 2 (B), the deep hole processing tip tool 1a has a tool body 2 having a cylindrical shape as a whole, and 3 attached to the tip surface 3 of the tool body 2. Each cutting blade 5 a to 5 c and first to fourth guide pads 6 a to 6 d disposed around the periphery of the tip surface 3 and the circumferential surface (side surface) of the tool body 2.
The tool main body 2 is made of, for example, steel for machine structural use, and the tip end surface 3 is an arc surface which gently curves with the rotation center (center) C as an apex.

Further, the cutting edges 5a to 5c are made of cemented carbide (WC), for example, and the center side tip 5b including the rotation center C of the tip surface 3 in the blade surface, and a part from the periphery of the tip surface 3 A protruding outer peripheral side chip 5a and an intermediate chip 5c arranged at an intermediate position opposite to the outer peripheral side chip 5a across the rotation center C of the front end surface 3 and arranged linearly with the chips 5a and 5b It consists of That is, such tips 5a to 5c have respective blade surfaces for cutting the workpiece on a common straight line passing through the rotation center C in the tip surface 3, and the total of the three tips is the tip. It constitutes a cutting edge slightly longer than the radius of the surface 3. Therefore, the blade surface of the intermediate chip 5c is disposed in the opposite direction to the blade surfaces of the outer peripheral chip 5a and the central chip 5b.
The diameter of the tool body 2 and the inner diameter of the deep hole to be drilled in the workpiece are, for example, 50 to 60 mm or more by using the cutting blades 5a to 5c consisting of the three tips 5a to 5c as described above. Even if the diameter is large, cutting resistance can be effectively reduced, and uniform cutting can be easily performed on substantially the entire tip surface 3.
For the tips 5a to 5c, indexable tips that are easy to replace are preferably used.

Furthermore, the first to fourth guide pads 6a to 6d are made of the same cemented carbide as described above, and have a flat rectangular parallelepiped shape as a whole, and the outer peripheral surface is outward like the circumferential surface of the tool main body 2 It has a convex curved surface. Most of the first to fourth guide pads 6a to 6d are inserted in the grooves formed along the axial direction on the circumferential surface of the tool main body 2 except for the curved surface side, Not fixed with multiple bolts.
As shown in FIG. 1, when the position of an imaginary radial line passing from the center of rotation C to the blade surfaces of the cutting blades 5a to 5c is 0 degree on the front end surface 3 of the tool body 2, the cutting blade The first guide pad 6a is rotated 180 degrees ± 10 degrees to a position (angle θ1) rotated 90 degrees ± 10 degrees in the direction (direction) to receive the cutting force 5a to 5c, and the second guide to a position (angle θ2) The fourth guide pad 6d is disposed at a position (angle θ4) at which the third guide pad 6c is rotated by 270 ° ± 10 degrees at a position (angle θ3) at which the pad 6b is rotated at 220 ° ± 10 °.
Incidentally, in FIG. 1, the position θ1 of the first guide pad 6a is 90 degrees, the position θ2 of the second guide pad 6b is 180 degrees, the position θ3 of the third guide pad 6c is 225 degrees, and the position θ4 of the fourth guide pad 6d. Although it is 270 degrees, it is not restricted to these.

The reason why the first to fourth guide pads 6a to 6d are disposed at each position as described above in the deep hole drilling tip tool 1a of the present invention is as follows.
In the case of a deep hole processing tip tool in which three guide pads are disposed at each of the positions θ1, θ2 and θ4 as conventionally known (the above-mentioned Patent Document 1), the diameter when processing a deep hole in a workpiece Because of the vibration along the direction and the displacement along the axial direction, the cross section of the formed deep hole often has a substantially triangular or nearly pentagonal shape.
Further, as in the case of Patent Document 2, when arranging three guide pads, the first and second guide pads are arranged every θ1 and θ2, and the third guide pad is arranged at 181 degrees to 220 degrees. Although the tip tool which aimed at the roundness improvement by having been arranged in the range position is proposed, the limit by being three remained.

The inventor uses four guide pads to reliably reduce vibration along the radial direction and displacement along the axial direction when deep-piercing a workpiece, and uses the first to fourth guides. The positions at which the pads 6a to 6d are to be arranged are individually defined as the θ1 to θ4.
Therefore, even if the first to third guide pads 6a to 6c contact the inner wall surface of the processed deep hole during deep hole processing and receive an outward force, the fourth guide pad 6d is directed to the rotation center C. It is considered that since the force is received as a whole, balance is achieved as a whole, and the cross section of the deep hole formed in the material to be processed does not easily become triangular, and becomes a perfect circular shape (effect (1)).
Furthermore, even if the first and second guide pads 6a and 6b contact the inner wall surface of the processed deep hole during deep hole processing and receive an outward force, the third and fourth guide pads 6c and 6d Because the force in the direction of the center of rotation C is received, the balance as a whole is well balanced, and the cross section of the deep hole formed in the workpiece is unlikely to be a pentagonal shape and becomes a perfect circle shape (effect (2)). .
The reasons for the above viewpoints will be specifically described later by examples.

In addition, as shown in FIG. 1, FIG. 2 (A), (B), in the front end surface 3 of the said tool main body 2, for insertion of said cutting blade 5a-5c and 1st-4th guide pad 6a-6d Two (multiple) openings 8 and 9 are opened at positions excluding each recess, and the openings 8 and 9 pass through the rear end 4 side of the tool body 2 along the axial center. It is focused to communicate with the through hole 7.
That is, as shown in the schematic view of FIG. 3, the boring head 10 which is elongated from one end face to the workpiece W of a round bar which is rotated at high speed with both ends restrained by a large lathe (not shown) The deep hole machining is performed by attaching the deep hole machining tip tool 1a to the front end of the workpiece and sequentially pressing these along the axial direction of the central portion of the workpiece W.
A long through hole 11 is located at the center of the boring head 10, and the through hole 11 communicates with the through hole 7 on the tip tool 1a side. In the gap between the tool body 2 of the tip tool 1a and the boring head 10 and the inner peripheral surface of the deep hole formed in the workpiece W, the cutting oil is on the tip surface 3 side of the tip tool 1a from the right in FIG. Supplied by high pressure. Such cutting oil is discharged to the right side (outside) of FIG. 3 through the through holes 7 and 11 from the openings 8 and 9 of the tip surface 3 together with cutting chips cut in the cutting edges (tips) 5a to 5c. Ru.
The discharged cutting oil is recycled after the chips are removed by passing through a sieve and a magnetic filter.

In the following, examples of the present invention will be described together with comparative examples.
Prepare two round rod workpieces W with a diameter of 12 cm and a length of 1000 cm, made of austenitic stainless steel (JIS: equivalent to SUS 304) and hardened by warm forging in advance. Was rotatably constrained to a large lathe.
In the axial direction of the workpiece W described above, the cutting blades 5a to 5c consisting of three throwaway tips are arranged in advance at the tip of the boring bar 10 having a diameter of 56 mm and a length of 1000 cm, and having a diameter of 67 mm The tool body 2 and the first to fourth guide pads 6a to 6d were disposed at the following positions, and the deep hole processing tip tool 1a of the embodiment was prepared.
In the embodiment, the position θ1 of the first guide pad 6a is 90 degrees, the position θ2 of the second guide pad 6b is 180 degrees, the position θ3 of the third guide pad 6c is 221 degrees, and the position θ4 of the fourth guide pad 6d is 270 degrees And
On the other hand, the tool body 2 with a diameter of 67 mm including the cutting blades 5a to 5c is attached to the same tip of the boring bar 10 as above, and the first, second and fourth guide pads 6a, 6b and 6d are The tip tool for deep hole processing of the comparative example which carried out the position arrangement of was prepared.
The position θ1 of the first guide pad 6a in the comparative example is 90 degrees, the position θ2 of the second guide pad 6b is 180 degrees, and the position θ4 of the fourth guide pad 6d is 270 degrees (except for the third guide pad 6c). And the same as those described in Patent Document 1).

One of the workpieces W is rotated in the circumferential direction at a rotational speed of 240 rpm, and the boring bar 10 and the deep hole processing tip tool 1a of the embodiment are arranged along the axial direction of the workpiece W every minute Deep penetration was performed to obtain a deep hole having an inner diameter of 68 mm by advancing along the central axis of the workpiece W at a feed speed of 38 mm (Example).
Furthermore, while rotating the remaining workpiece W at the same rotational speed as above, the same boring speed as the above for the boring bar 10 and the deep hole processing tip tool of the comparative example along the axial direction of the workpiece W The deep hole processing for obtaining a deep hole having an inner diameter of 68 mm was performed by advancing along the central axis of the workpiece W (comparative example).

The two deep-pierced workpieces W using the deep-hole processing tip tool 1a of the embodiment and the deep-hole processing tip tool of the comparative example are cut at a position of 100 mm from the end surface where the cutting is started. The circularity of the inner surface of the deep hole appearing for each cut surface is individually measured using a circle measuring machine having a contact type sensor, and the results are shown in the circle graph of FIG. It was shown to.
As shown in FIG. 4, the contact locus (roundness) of the embodiment shown by the solid line is substantially similar to the imaginary circular shape shown by the one-dot chain line all around. On the other hand, the contact locus (roundness) of the comparative example indicated by the broken line in FIG. 4 is largely deviated from the substantially circular shape and the perfect circle indicated by the alternate long and short dash line. According to this result, it was revealed that the deep hole machining according to the example is superior in roundness to the deep hole machining according to the comparative example.

Further, during the deep hole drilling, the vertical surfaces of the circumferential surfaces of the two workpieces W being deep hole drilled using the deep hole drilling tip tool 1a of the embodiment and the deep hole drilling tip tool of the comparative example The displacement in the radial direction due to vibration in the direction and horizontal direction is measured along substantially the entire length in the axial direction for each workpiece W, and the displacement in the two directions and the axial distance (length) in the workpiece W Two basic graphs were obtained.
By subjecting the two basic graphs to known FFT analysis (Fourier analysis), graphs (frequency-displacement) showing displacement of each vibration frequency (frequency spectrum) were obtained for the example and the comparative example. The results are shown in the graph of FIG. In the graph of FIG. 5, the comparative example of the broken line almost overlapped with the example of the solid line at a low displacement amount.
As shown in FIG. 5, in the embodiment shown by the solid line, the displacement peak of 7.76 μm appeared at the frequency of about 16 Hz, while in the comparative example shown by the broken line, the vibration was at the displacement of about 35 Hz. A peak of 11.92 μm appeared. Therefore, as shown by the open arrow in FIG. 5, it was found that deep hole machining according to the example is superior to deep hole machining according to the comparative example in both the frequency of vibration and the displacement amount.

Furthermore, the two deep-pierced two workpieces W using the deep hole drilling tip tool 1a of the embodiment and the deep hole drilling tip tool of the comparative example are placed every 50 cm from the end face where the cutting is started. It cut | disconnected one by one and measured the displacement amount in processing length distinction. The results are shown in the graph of FIG.
As shown in FIG. 6, in the deep hole machining according to the example, the displacement amount was about 4.5 mm when the machining length reached 700 cm, whereas in the deep hole machining according to the comparative example, the machining length was When it reached 250 cm, the displacement amount was about 4.2 mm. From these results, it was found that the deep hole processing according to the example is excellent in straightness.
It will be easily understood that the effects (1) to (4) by the deep hole processing tip tool 1a are supported by the deep hole processing of the embodiment shown in FIGS.

FIG. 7 is a plan view showing a deep hole processing tip tool 1b of a different form, and FIGS. 8A and 8B are side views along the arrow A direction or the arrow B direction in FIG.
As shown in FIGS. 7, 8A and 8B, the deep hole processing tip tool 1b individually has the tool main body 2 including the tip surface 3 similar to the above, and the positions θ1 to θ4 similar to the above. The single cutting blade 5 is attached along the radial direction from the rotation center C of the tip surface 3 with the first to fourth guide pads 6a to 6d arranged. A single opening 8 is opened in the tip end surface 3 excluding the cutting blade 5, and the opening 8 communicates with the through hole 7 on the rear end 4 side. The deep hole processing tip tool 1b is suitable for a relatively small diameter tool having a diameter of, for example, 40 to 30 cm or less.
Also by the deep hole processing tip tool 1b as described above, it is possible to obtain the same effects as the effects (1) to (4).

The present invention is not limited to the embodiments and examples described above.
For example, the cutting blade is composed of five tips, and the central tip near the center C of the tip surface 3, the outer peripheral tip on the peripheral side, the intermediate tip located between them, and the outer peripheral side It may be configured such that it is composed of two intermediate tips which are located on the opposite side in the radial direction of the tips and approximately in the radial direction between the three tips.
Further, the cutting blades 5, 5a-5c and the first to fourth guide pads 6a-6d are not limited to the above-mentioned cemented carbide but may be made of cermet or fine ceramic such as partially stabilized zirconia. Furthermore, the recess of the tool body 2 for receiving the bottom side of the first to fourth guide pads 6a to 6d may be a wide bottom recessed groove having a bottom surface wider than the opening.
In addition, three or more openings may be provided in the distal end surface 3 of the tool body 2 and in communication with the through hole 7.

  According to the present invention, it is possible to remarkably reduce unstable vibration due to the tip tool and the boring bar during deep hole machining, and to make it possible to reliably approximate the cross section of the deep hole formed in the workpiece to a perfect circle. The tip tool for hole processing can be provided reliably.

1a, 1b ......... deep hole machining tool bit 2 ..................... tool body 3 ..................... tip surface 5,5A～5c ... cutting edge 6a~6d ......... guide pad 7 ... ............ Through hole 8, 9 開口 Opening 10 ボ ー リ ン グ Boring bar C ............... Center of rotation W ............... Workpiece θ1 θ4 ..... Angle (position)

Claims (4)

The cutting oil attached to the tip of the boring bar and supplied from the gap between the tool body and the processed deep hole in the workpiece is discharged together with the chips through the inside of the tool body and bow link bar to the rear end side Tool for deep hole processing,
A tool body that exhibits a cylindrical shape as a whole;
A cutting blade attached to the end face of the tool body,
First to fourth guide pads disposed between the periphery of the tip surface of the tool body and the circumferential surface of the tool body,
When the position of an imaginary radial line passing through the blade surface of the cutting blade from the center of rotation of the tip surface of the tool body is 0 degree, the direction of receiving the cutting force of the cutting blade is rotated 90 degrees ± 10 degrees A position where the first guide pad is rotated 180 degrees ± 10 degrees, a second guide pad is rotated 220 degrees ± 10 degrees, a third guide pad is rotated 270 degrees ± 10 degrees The fourth guide pad is disposed on the
Tool for deep hole machining characterized by The third guide pad is disposed at a position rotated 221 to 230 degrees in a direction to receive the cutting force of the cutting edge when the position of the cutting edge is 0 degree from the rotation center of the tip surface of the tool main body Being
The deep hole processing tip tool according to claim 1, characterized in that: At the tip end face of the tool body, at a position excluding the cutting edge, one or more openings communicating with the through holes for discharging the cutting oil and cutting debris are located.
The deep hole processing tip tool according to claim 1 or 2, characterized in that The cutting blade includes a central tip including the rotation center of the tip surface of the tool body, an outer circumferential tip partially protruding outward from the periphery of the tip surface, and the outer circumferential tip rotates the tip surface. It is arranged at the opposite middle position across the center, and is composed of the respective chips and the middle chips arranged linearly along the diameter line,
The deep hole processing tip tool according to any one of claims 1 to 3, characterized in that:

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