JP2015120216A - Deep hole processing device and deep hole processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deep hole processing device capable of improving durability of a guide bush.SOLUTION: A deep hole processing device 1 applies drilling and the like to a workpiece 2 by rotating a blade tool 20 around an axis. A guide bush 30 provided away from an outer periphery of the blade tool 20 on the radial outside of the blade tool 20 has an exhaust nozzle 31 for emitting a jet of oil toward the outer periphery of the blade tool 20. Thus, since an oil film is formed between an inner wall of the guide bush 30 and the blade tool 20, the blade tool 20 is rotated in the state of noncontact with the inner wall of the guide bush 30.

Description

  The present invention relates to a deep hole machining apparatus and a deep hole machining method.

Conventionally, there has been known a deep hole drilling device that drills a non-worked material such as metal or resin (hereinafter referred to as “work”) with a drill, or finishes an inner wall of a hole formed in a workpiece with a reamer. ing. Hereinafter, in this specification, a drill or a reamer is referred to as a “blade”. Moreover, in this specification, a deep hole means a thing deeper than the diameter of a hole.
The deep hole machining apparatus described in Patent Document 1 includes a guide bush on the outer diameter side of a blade for drilling a workpiece. The guide bush suppresses the whirling of the blade tip of the blade that occurs when the blade is rotated at a high speed.

JP 2002-321111 A

However, the deep hole machining apparatus described in Patent Document 1 has a configuration in which the inner wall of the guide bush and the cutting tool are in contact with each other. Therefore, when the blade is rotated at a high speed, the amount of heat generated may increase due to friction, or the guide bush may be worn. As a result, the durability of the guide bush is lowered, and there is a concern that the period during which the guide bush can be used is shortened.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a deep hole machining apparatus and a deep hole machining method capable of enhancing the durability of the guide bush.

A first invention is a deep hole drilling device for drilling a workpiece by a cutting tool rotating around an axis, and a guide bush provided away from the outer periphery of the cutting tool is a jet that ejects gas or liquid toward the outer periphery of the cutting tool It has an outlet.
As a result, a thin film of gas or liquid is formed between the inner wall of the guide bush and the blade, so that the inner wall of the guide bush and the blade rotate without contact. Therefore, heat generation and wear due to friction between the guide bush and the cutting tool are suppressed. Therefore, the deep hole machining apparatus can improve the durability of the guide bush.

The second invention is an invention of a deep hole machining method. This deep hole machining method is characterized in that the pressure of the gas or liquid ejected from the ejection hole of the guide bush is adjusted to such an extent that the blade and the inner wall of the guide bush are maintained in non-contact.
Thereby, the heat_generation | fever and abrasion by friction with a guide bush and a blade tool can be suppressed.

It is a block diagram of the deep hole processing apparatus by 1st Embodiment of this invention. It is sectional drawing of the front-end | tip part of the blade provided with a deep hole processing apparatus. It is sectional drawing of the guide bush with which a deep hole processing apparatus is provided. It is an expanded view of the guide bush with which a deep hole processing apparatus is provided. It is explanatory drawing which shows the motion of the blade tool in the case of deep hole processing. It is an expanded view of the guide bush of the deep hole processing apparatus by 2nd Embodiment. It is sectional drawing of the guide bush of the deep hole processing apparatus by 3rd Embodiment. It is an expanded view of the guide bush of the deep hole processing apparatus by 4th Embodiment. It is a perspective view of the deep hole processing apparatus by 5th Embodiment. It is sectional drawing of the XX line of FIG. It is a block diagram of the deep hole processing apparatus by 5th Embodiment. It is a perspective view of the deep hole processing apparatus by 6th Embodiment. It is sectional drawing of the XIII-XIII line | wire of FIG. It is a perspective view of the deep hole processing apparatus by 7th Embodiment. It is sectional drawing of the XV-XV line | wire of FIG. It is a block diagram of the deep hole processing apparatus by 7th Embodiment. It is a block diagram of the deep hole processing apparatus by 7th Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A first embodiment of the present invention is shown in FIGS. The deep hole machining apparatus 1 according to the first embodiment drills a workpiece 2 such as metal or resin.
As shown in FIG. 1, the deep hole machining apparatus 1 includes a rotation mechanism 10, a cutting tool 20, a guide bush 30, and the like.
An example of the rotation mechanism 10 is a small spindle motor. The cutting tool 20 is attached to the rotating mechanism 10 at one end in the axial direction, and rotates around the axis by driving the rotating mechanism 10.

FIG. 2 shows a state in which a drilling process is performed on the workpiece 2 with the blade 20.
The blade 20 is of a so-called BTA (Boring & Trepanning Association) type having a supply passage 22 and a discharge passage 23 on the inner diameter side of the outer peripheral wall.
An annular guide wall 21 is provided on the outer periphery of the blade 20. The supply passage 22 extends in the axial direction of the blade 20, and opens toward the distal end side of the blade 20 from the guide wall 21. The supply passage 22 can supply cutting fluid to the tip of the cutting tool 20.
The discharge passage 23 is provided at the axial center of the blade 20 and opens at the tip of the blade 20. The discharge passage 23 can discharge chips generated by drilling the workpiece 2 together with the cutting fluid.
In FIG. 2, the flow of the cutting fluid is indicated by arrows AE.

  When the tip of the cutting tool 20 enters the hole of the workpiece 2, the guide wall 21 described above is slidably brought into contact with the inner wall of the hole to suppress the swinging of the cutting tool 20. The guide wall 21 does not exhibit the function of suppressing the swinging of the blade 20 until it enters the hole of the workpiece 2.

As shown in FIG. 1, the guide bush 30 is provided in the vicinity of the workpiece 2 and can be inserted through the cutting tool 20. By providing the guide bush 30 in the vicinity of the work 2, it is possible to effectively suppress the whirling of the cutting tool 20 with the attachment point of the rotation mechanism 10 as a fulcrum.
Note that the cutting tool 20 inserted through the guide bush 30 is provided with the supply passage 22 and the discharge passage 23 on the inner diameter side of the outer peripheral wall. It is circular.

As shown in FIGS. 3 and 4, the guide bush 30 is provided on the outer diameter side of the cutting tool 20, slightly away from the outer periphery of the cutting tool 20. The guide bush 30 has an ejection hole 31, a restriction portion 32, and a groove portion 33.
The ejection hole 31 opens to the inner peripheral wall of the guide bush 30 and can eject gas or liquid to the inside of the guide bush 30 in the diameter. The ejection hole 31 of this embodiment ejects the oil supplied from the hydraulic pressure supply means 3 toward the outer periphery of the blade 20 at a predetermined pressure.
The groove portion 33 is provided on the inner peripheral wall of the guide bush 30 and can store the oil ejected from the ejection hole 31. The groove portion 33 of the present embodiment includes an X groove 34 extending in an X shape centering on the opening of the ejection hole 31 and a plurality of dimples 35.

The restriction portion 32 is a portion where the groove portion 33 is not provided on the inner wall of the guide bush 30 on one side and the other side of the guide bush 30 in the axial direction. The restricting portion 32 restricts the amount of gas or liquid that leaks from between the outer periphery of the blade 20 and the guide bush 30. In FIG. 3, the flow of oil supplied to the ejection hole 31 is indicated by an arrow F, and the flow of oil leaking from between the outer periphery of the restriction portion 32 and the restriction portion 32 is indicated by an arrow G. By adjusting the flow rate of oil ejected from the opening of the ejection hole 31 and the flow rate of oil leaking from between the outer periphery of the cutting tool 20 and the restricting portion 32, the oil is stored between the outer periphery of the cutting tool 20 and the guide bush 30. The hydraulic pressure is determined. The flow rate of oil leaking from between the outer periphery of the blade 20 and the restricting portion 32 is determined by the distance d therebetween.
The oil leaking from the restricting portion 32 can be reused after removing foreign matter with a filter (not shown).

Next, the deep hole processing method using the deep hole processing apparatus 1 mentioned above is demonstrated.
The deep hole machining method includes an ejection process, a pressure adjustment process, and a hole machining process.
In the ejection step, oil is supplied from the hydraulic pressure supply means 3 to the ejection hole 31 of the guide bush 30, and the oil is ejected from the opening of the ejection hole 31.
In the pressure adjusting step, the hydraulic pressure supplied from the hydraulic pressure supply means 3 to the ejection hole 31 is adjusted to such an extent that the blade 20 and the inner wall of the guide bush 30 can be maintained in a non-contact manner. Since the cutting edge 20 tends to swing as the blade 20 rotates at a higher speed, it is preferable to increase the hydraulic pressure supplied from the hydraulic pressure supply means 3 to the ejection hole 31 as the rotational speed of the blade 20 is increased.
Further, when the distance d between the outer periphery of the blade 20 and the restricting portion 32 is short, the hydraulic pressure supplied from the hydraulic pressure supply means 3 to the ejection hole 31 can be adjusted to be low. On the other hand, when the distance d between the outer periphery of the blade 20 and the restricting portion 32 is long, the hydraulic pressure supplied from the hydraulic pressure supply means 3 to the ejection hole 31 is adjusted to be high.

In the hole drilling process, the cutting tool 20 is rotated around the axis by driving the rotation mechanism 10 to drill the workpiece 2. At this time, cutting fluid is supplied to the tip of the cutting tool 20 through the supply passage 22 of the cutting tool 20, and chips generated by drilling the workpiece 2 are discharged together with the cutting fluid through the discharge passage 23.
Until the annular guide wall 21 provided at the tip of the blade 20 slides with the inner wall of the hole of the workpiece 2, the blade 20 is prevented from swinging by the guide bush 30. The guide bush 30 suppresses the whirling of the blade 20 without contacting the blade 20.

FIG. 5 shows how the guide bush 30 suppresses the swinging of the blade 20. In FIG. 5, the groove portion 33 of the guide bush 30 is omitted.
In the hole drilling process, as the blade 20 is rotated at high speed, the centrifugal force increases and the tip of the blade 20 tends to swing. Therefore, the central axis O2 of the blade 20 revolves around the central axis O1 of the guide bush 30. The hydraulic pressure between the inner wall of the guide bush 30 and the cutting tool 20 at this time is indicated by a one-dot chain line α and an arrow β in FIG. The hydraulic pressure increases as the distance between the inner wall of the guide bush 30 and the cutting tool 20 decreases, and decreases as the distance between the inner wall of the guide bush 30 and the cutting tool 20 increases. Therefore, the oil film γ is formed between the inner wall of the guide bush 30 and the cutting tool 20 due to the repulsive force of the oil, and the cutting tool 20 rotates without contact with the inner wall of the guide bush 30. As a result, the torque unevenness due to the friction between the inner wall of the guide bush 30 and the cutting tool 20 is eliminated, so that the swinging of the cutting tool 20 is further suppressed. Further, even if the cross-sectional shape of the inner periphery of the guide bush 30 or the outer periphery of the blade 20 is not a perfect circle due to manufacturing tolerances, the swirl due to the influence is reduced by the oil film γ.

The first embodiment provides the following operational effects.
(1) The deep hole machining apparatus 1 of the first embodiment includes a guide bush 30 having an ejection hole 31 through which oil can be ejected toward the outer periphery of the blade 20. As a result, an oil film γ is formed between the inner wall of the guide bush 30 and the blade 20, and the blade 20 rotates without contact with the inner wall of the guide bush 30. Therefore, since heat generation and wear due to friction between the guide bush 30 and the blade 20 are suppressed, the durability of the guide bush 30 can be enhanced.

(2) In the first embodiment, the supply passage 22 and the discharge passage 23 of the blade 20 are provided on the radially inner side of the outer peripheral wall of the blade 20. Thereby, it is possible to make the outer periphery of the blade 20 cylindrical. Therefore, it is possible to regulate the flow rate of oil leaking from the gap between the regulating portion 32 of the guide bush 30 and the cutting tool 20 and maintain the oil pressure inside the guide bush 30. Therefore, an oil film γ can be formed between the inner wall of the guide bush 30 and the blade 20.

(3) In 1st Embodiment, the guide bush 30 has the control part 32 in the inner wall of one and the other of the axial direction. The oil pressure inside the guide bush 30 can be maintained by adjusting the gap d between the restricting portion 32 and the blade 20.

(4) In 1st Embodiment, the guide bush 30 has the groove part 33 in the inner wall of the radial direction. As the groove 33 stores oil, the oil pressure inside the guide bush 30 is kept constant. Therefore, an oil film γ can be formed between the inner wall of the guide bush 30 and the blade 20.

(5) In the deep hole machining method of the first embodiment, the hydraulic pressure ejected from the ejection hole 31 of the guide bush 30 is adjusted to such an extent that an oil film γ can be formed between the inner wall of the guide bush 30 and the blade 20. . Thereby, since the inner wall of the guide bush 30 and the blade 20 rotate without contact, heat generation and wear due to friction between the guide bush 30 and the blade 20 can be suppressed.

(Second Embodiment)
A deep hole machining apparatus according to a second embodiment of the present invention will be described with reference to FIG. Hereinafter, in the plurality of embodiments, the same reference numerals are given to substantially the same configurations as those in the first embodiment described above, and the description thereof is omitted.
In the second embodiment, the guide bush 40 of the deep hole machining apparatus has a porous material having a plurality of pores 41 on the inner wall in the radial inner direction. FIG. 6 is a development view of the inner wall of the guide bush 40, and schematically shows a plurality of pores 41 of the porous material in an enlarged manner. In the second embodiment, the plurality of pores 41 of the porous material correspond to the ejection holes described in the claims.
The guide bush 40 ejects air supplied from an air supply means (not shown) through the pores 41 of the porous material at a predetermined pressure. The air supply means is exemplified by a compressor of factory equipment.

The guide bush 40 regulates the flow rate of air leaking from between the inner wall of the guide bush 40 and the outer periphery of the blade 20 on one and the other inner walls in the axial direction. By adjusting the flow rate of air ejected from the pores 41 of the porous material and the flow rate of air leaking from the gap between the inner wall of the guide bush 40 and the outer periphery of the blade tool 20, the gap between the guide bush 40 and the blade tool 20 is adjusted. The stored air pressure is determined.
By forming an air layer between the inner wall of the guide bush 40 and the blade 20, the blade 20 rotates without contact with the inner wall of the guide bush 40.

  In the second embodiment, the guide bush 40 has a porous material having a plurality of pores 41 on the inner wall in the radial inner direction. Thereby, it is possible to eject air from the plurality of pores 41 of the porous material toward the entire circumference of the blade 20 and form an air layer between the inner wall of the guide bush 40 and the blade 20. . Therefore, heat generation and wear due to friction between the guide bush 40 and the blade 20 can be suppressed, and the durability of the guide bush 40 can be enhanced.

(Third embodiment)
A deep hole machining apparatus according to a third embodiment of the present invention will be described with reference to FIG.
In the third embodiment, the inner wall in the radial direction of the guide bush 50 is formed by three arcuate surfaces 51, 52, 53 as viewed from the axial direction. The circular arc surfaces 51, 52, 53 are convex in the radially outward direction. Thereby, three locations where the distance between the inner wall of the guide bush 50 and the blade 20 is short are formed at equal intervals on the circumference of the blade 20. On the other hand, three locations where the distance between the inner wall of the guide bush 50 and the blade 20 is long are formed at equal intervals on the circumference of the blade 20. The repulsive force due to the hydraulic pressure at a location where the distance between the inner wall of the guide bush 50 and the cutting tool 20 is close is greater than the repulsive force due to the hydraulic pressure at a location where the distance between the inner wall of the guide bush 50 and the cutting tool 20 is far.

  The ejection holes 54, 55, 56 of the guide bush 50 open at a location where the distance between the inner wall of the guide bush 50 and the blade 20 is far, and eject oil supplied from the hydraulic pressure supply means 3 at a predetermined pressure. Therefore, the ejection holes 54, 55, 56 do not hinder the repulsive force due to the hydraulic pressure at a location where the distance between the inner wall of the guide bush 50 and the blade 20 is short. Further, since the ejection holes 54, 55, and 56 are provided at all locations where the distance between the inner wall of the guide bush 50 and the blade 20 is long, variations in hydraulic pressure inside the guide bush 50 are suppressed.

In the third embodiment, the guide bush 50 has an inner wall formed by three arcuate surfaces 51, 52, 53. Thereby, three places where the repulsive force by hydraulic pressure is large are formed on the inner wall of the guide bush 50. Therefore, the swinging of the blade 20 can be suppressed by supporting the oil film at three points.
In the third embodiment, the inner wall of the guide bush 50 is formed by the three arc surfaces 51, 52, 53. However, the inner wall of the guide bush 50 may be formed by an odd number of arc surfaces of three or more. As a result, the guide bush 50 can support the cutting tool 20 at an odd number of locations, and the swinging of the cutting tool 20 can be suppressed.

(Fourth embodiment)
A deep hole machining apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a development view of the inner wall of the guide bush 60 of the deep hole machining apparatus.
In the fourth embodiment, the guide bush 60 has three ejection holes 61, 62, 63, a plurality of V-shaped grooves 64, and a restricting portion 65 on the inner wall in the radially inward direction.
The ejection holes 61, 62, 63 eject oil supplied from the hydraulic pressure supply means 3 at a predetermined pressure. The groove portion 64 can store oil ejected from the ejection holes 61, 62, and 63.
In 4th Embodiment, there exists an effect similar to 1st-3rd embodiment mentioned above.

(Fifth embodiment)
A deep hole machining apparatus according to a fifth embodiment of the present invention will be described with reference to FIGS. 9, 12, and 14, the guide bush 30 is shown as a partial cross-sectional view.
In the fifth embodiment, the blade 20 is provided with two discharge passages 24 and 25 in the radially outward direction from the center of the shaft. The two discharge passages 24 and 25 are open to the tip end side of the blade 20 and the rotation mechanism side. The discharge passages 24 and 25 have a chip introduction port 26 on the distal end side of the blade 20 and a chip discharge port 27 on the rotating mechanism side.
As shown in FIGS. 9 and 10, the blade 20 has a cover portion 28 that covers the outer diameter side of the discharge passages 24 and 25. The outer periphery of the cutting tool 20 is formed in a cylindrical shape at the portion having the cover portion 28. The guide bush 30 is provided on the outer diameter side of the cover portion 28.

  Here, as shown in FIG. 11, the length of the cover portion 28 in the axial direction is L1, and the length of the guide bush 30 is L2. The depth of the drilling process 4 of the workpiece 2 is L3. At this time, the axial length L1 of the cover portion 28 is longer than the sum of the length L2 of the guide bush 30 and the depth L3 of the workpiece drilling process 4. That is, L1> L2 + L3. Thereby, it is possible to regulate the flow rate at which gas or liquid leaks from the gap between the regulating portion 32 of the guide bush 30 and the cover portion 28. Therefore, the air pressure or hydraulic pressure stored between the guide bush 30 and the cover portion 28 can be maintained, and an air layer or oil film can be formed therebetween.

  In the fifth embodiment, chips generated by drilling can be discharged well by the plurality of discharge passages 24 and 25, and heat generation and wear due to friction between the guide bush 30 and the blade 20 can be suppressed. it can.

(Sixth embodiment)
The deep hole processing apparatus of 6th Embodiment of this invention is demonstrated with reference to FIG.12 and FIG.13.
In the sixth embodiment, the cutting tool 20 includes a discharge passage 29 around the axis. The discharge passage 29 has a chip introduction port 26 on the distal end side of the cutting tool 20 and a chip discharge port 27 on the rotating mechanism side.
As shown in FIG. 13, the blade 20 has a cover portion 28 that covers the radially outer side of the discharge passage 29. The outer periphery of the cutting tool 20 is formed in a cylindrical shape at the portion having the cover portion 28. The guide bush 30 is provided on the outer diameter side of the cover portion 28. Therefore, atmospheric pressure or hydraulic pressure is stored between the guide bush 30 and the cover portion 28, and an air layer or an oil film is formed therebetween.

(Seventh embodiment)
A deep hole machining apparatus according to a seventh embodiment of the present invention will be described with reference to FIGS.
In the seventh embodiment, the cutting tool 20 does not include a discharge passage. The guide bush 30 is provided closer to the rotation mechanism than the tip notch 200 of the blade 20.
As shown in FIG. 15, the blade 20 has a columnar shape on the rotating mechanism side with respect to the tip notch 200. Therefore, atmospheric pressure or hydraulic pressure is stored between the guide bush 30 and the outer periphery of the blade 20, and an air layer or an oil film is formed therebetween.

As shown in FIG. 16, the cutting tool 20 of the seventh embodiment can finish the inner wall of the through hole 5 penetrating the work 2. In this case, chips generated by cutting are discharged from the opening 6 on the side opposite to the blade 20 of the through hole 5.
As shown in FIG. 17, the cutting tool 20 of the seventh embodiment can finish the inner wall of the blind hole 7 formed in the workpiece 2. The blind hole 7 has an opening 8 in the lateral direction. In this case, chips generated by finishing the blind hole 7 are discharged from the opening 8.

(Other embodiments)
In the above-described embodiment, the deep hole machining apparatus that drills a workpiece has been described. On the other hand, in another embodiment, the deep hole machining apparatus may perform a finishing process on the inner wall of the hole formed in the workpiece.
The cutting tool of the present invention may have any configuration as long as the cutting tool rotates around an axis and performs drilling or finishing on a workpiece.
The present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 ... Deep hole processing apparatus 2 ... Work 10 ... Rotating mechanism 20 ... Cutting tool 22 ... Supply passage 30,40,50,60 ... Guide bush 31,41,54,55, 56, 61, 62, 63 ... ejection holes

Claims (10)

A cutting tool (20) that rotates around an axis to drill or finish the workpiece (2);
A rotating mechanism (10) for rotating the cutting tool;
It has an ejection hole (31, 41, 54, 55, 56, 61, 62, 63) that is provided apart from the outer periphery of the blade and ejects gas or liquid toward the outer periphery of the blade rotated by the rotation mechanism. A deep hole drilling device (1) comprising a guide bush (30, 40, 50, 60).   The guide bush (30, 60) has a restricting portion (32, 65) for restricting the amount of gas or liquid leaking from between the outer periphery of the blade and the guide bush on one and the other side in the axial direction. The deep hole processing apparatus according to claim 1.   3. The deep hole machining apparatus according to claim 1, wherein the guide bush has a groove (33, 64) capable of storing liquid on an inner wall in a radial inner direction thereof.   The said guide bush (40) has a porous material which has several pores (41) which can eject gas toward the outer periphery of the said blade tool in the inner wall of the radial inside direction. The deep hole processing apparatus described in 1.   The inner wall in the radial direction of the guide bush (50) is formed by an odd number of three or more arcuate surfaces (51, 52, 53) when viewed from the axial direction. Deep hole processing equipment. A discharge passage (23, 24, 25, 29) extending in the axial direction of the cutting tool and capable of discharging chips generated by drilling or finishing the workpiece;
The deep hole machining apparatus according to any one of claims 1 to 5, wherein the guide bush is installed at a location where the discharge passage is provided on a radially inner side than an outer periphery of the cutting tool.   The deep hole machining apparatus according to claim 6, wherein the discharge passage (23) is provided at an axial center of the cutting tool. The blade has a cover portion (28) that covers the outside of the diameter of the discharge passage (24, 25, 29),
The axial distance (L1) of the cover part is longer than the sum of the drilling depth (L3) of the workpiece and the axial length (L2) of the guide bush. 6. The deep hole processing apparatus according to 6. A deep hole machining method using the deep hole machining apparatus according to claim 1,
An ejection step of ejecting gas or liquid from the ejection holes of the guide bush;
And a pressure adjusting step of adjusting the pressure of the gas or liquid to such an extent that the inner wall of the guide bush and the cutting tool are maintained in a non-contact state. In the pressure adjustment step,
The closer the distance between the restriction portion provided on one and the other of the guide bush in the axial direction and the outer periphery of the blade, the lower the pressure of the gas or liquid ejected from the ejection hole,
The deep hole processing method according to claim 9, wherein the pressure of the gas or liquid ejected from the ejection hole is adjusted to be higher as the distance between the restriction portion of the guide bush and the outer periphery of the cutting tool is longer.

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