JP2880991B1 - Metal pillar drilling device - Google Patents

Abstract

An object of the present invention is to provide a drilling device that can improve the life of a plug and the quality of the inner surface of a material to be drilled in a drilling process of a long metal column. SOLUTION: The plug has a truncated conical shape which shares a symmetry axis with its outer shape or a shape having a cylindrical through hole continuous with the truncated cone, and a ceramic material or carbide having excellent wear resistance and seizure resistance. The plug is made of a cermet material containing at least 50% or more of one or more ceramics such as borides and oxides, using a fixing rod provided with a locking portion at one end and a fixing portion at the other end. A perforation device having a structure in which it is connected and fixed to a joint provided with a cylindrical through hole that shares a symmetry axis with its outer shape. With this drilling device,
A ceramic material and a cermet material having excellent seizure resistance and wear resistance can be applied to the plug without any practical problems, and the life of the plug and the inner surface quality of the material to be pierced are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a drilling device for improving the life of a plug and improving the inner surface quality of a material to be rolled in a drilling process of a long metal column.

[0002]

2. Description of the Related Art As a typical long metal column having a perforation process in a manufacturing process, a perforation process of a seamless steel pipe will be described below. In general, the drilling method in the process of manufacturing a seamless steel pipe is described in the Mannesmann drilling method described on page 921 of the Iron and Steel Institute of Japan, "Third Edition Steel Handbook III (2) Volume," and on page 940 of the same book. Press roll perforation method. In the Mannesmann drilling method, the plug being drilled undergoes shear deformation while rotating. On the other hand, the press roll perforation method is a press-perforation method, and the plug being bored undergoes compression deformation without rotating. The shape of the plug used in both drilling methods is generally axially symmetric, and furthermore, the drilling is mainly performed in the cross section of the plug in a plane including the axis of symmetry 16 of the plug 15 as shown in FIG. A tip A having a substantially arc-shaped cross section including a symmetrical axis 16 of the outer shape of the plug 15 in which the diameter of the plug gradually increases from the leading end to the trailing end of the plug 15 is formed. A smoothing pipe for smoothing the inner surface of the rear end portion B whose diameter is the same as and constant as the diameter of the inner surface of the cylindrical material to be rolled after drilling, or which gradually increases from the front end to the rear end, and the front end The connecting portion Y is configured to smoothly connect the portion A and the rear end portion B with a diameter gradually changing.

FIG. 8 is a partially cutaway side view showing the outline of a Mannesmann perforating apparatus viewed from a direction perpendicular to the rolling direction of a roll. A material 18 to be pierced is pressed by a pair of barrel-shaped rolls 17. The speed component in the axial direction and the circumferential direction is given, and the plug 1 mounted on the tip of the cored bar 4 is press-fitted while receiving the roll pressure while rotating and advancing helically, thereby piercing.

FIG. 9 is a cross-sectional view showing an outline of a press roll punching device in a plane parallel to the rolling direction of the roll and including a pass line. The material to be pierced 18 is pressed from one side in the axial direction by a pushing device 20 to form a pair of hole-shaped rolls 19.
, And the plug 1 mounted on the tip of the cored bar 4 is press-fitted from the other side to make a hole.

FIG. 7 is a partially cutaway side view for explaining a commonly used drilling tool device. Generally, a drilling tool device includes a plug 1 as shown in FIG.
7 is connected to the metal core 4 via a screw connection portion S composed of a female screw processed into a metal screw and a male screw processed into the metal core 4, or as shown in FIG. And a male screw part processed at the other end of the joint 2 after being screw-coupled to the joint 2 via a screw connection part R composed of a female screw part processed into a joint and a male screw processed at one end of the joint 2. It is formed by screw-connecting to the metal core 4 via a screw connection portion T composed of a female screw portion processed into the metal core 4. Note that the joint 2 and the core 4 generally have a shape sharing a symmetric axis with the outer shape of the plug 1.

[0006] The material of the plug 1 is generally the same as the above-mentioned edition of the Iron and Steel Institute of Japan, "Third Edition Iron and Steel Handbook III (2) separate volume".
A low alloy steel containing several percent of Cr and Ni as described on page 935 is cast, and if necessary, forged.
After being machined into a predetermined shape, a metal oxide film is formed on the surface by heat treatment before use. By using the metal oxide film's seizure resistance, lubrication and heat insulation properties to protect the plug surface and prevent seizure between the material to be pierced and the plug and melting of the plug, Damage is prevented and good inner surface quality of the pierced material is maintained. In the press roll perforation method, a dead metal is formed at the tip of the plug during perforation, and the perforation is performed while protecting the plug. Therefore, the plug life is considered to be better than the Mannesmann perforation method.

However, in the case of drilling high alloy steel such as 13% Cr steel or austenitic stainless steel, the production of which has been increasing in recent years, the drilling load is high, the friction coefficient is high, and Since the plug material also contains Cr, seizure between the material to be pierced and the plug is liable to occur, and these high alloy steels are less likely to form a metal oxide film than carbon steel. The plug is worn out early and often has internal flaws, for example, because the metal oxide is hardly transferred from the perforated material to the plug, and the metal oxide film on the plug surface is worn away early. Since the inner surface flaws generated in the perforation process lead to the promotion of flaws in the post-process, in order to keep the product inner surface quality good,
Plugs need to be replaced before they become worn. For these reasons, the plug life is generally significantly reduced when drilling high alloy steel compared to when drilling carbon steel. A decrease in plug life has adverse effects such as an increase in manufacturing costs and a reduction in production efficiency due to the suspension of rolling work for drilling tool replacement. It is hoped that plug life will be improved by suppressing plug wear and preventing the occurrence of internal flaws in the material being drilled. It is rare.

As a remedy, a ceramic material or a cermet material is applied, and the surface of a plug surface layer made of a low alloy steel containing several% of Cr or Ni is modified by thermal spraying or the like with these materials. Although there is a method, generally the plug is 1
Because it is used for processing the inner surface of a perforated material at 200 ° C, it is constantly exposed to high temperatures during perforation and undergoes compression deformation in accordance with the perforation load, while its surface is caused by relative slip between the perforated material and the perforated material. This method is used in an extremely severe condition subjected to shear deformation, and then quenched by water cooling.In this method, the difference in thermal expansion between the surface-modified surface layer and the plug base material inside the surface layer There is a problem that cracks occur and the surface-modified surface layer peels off.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a metal column drilling apparatus for improving the life of a plug in a drilling step of a metal column and improving the inner surface quality of a material to be drilled. .

[0010]

Means for Solving the Problems The present inventors have studied the material and structure of a plug to improve the life of the plug and the inner surface quality of the material to be pierced, and have completed the invention.

According to the present invention, a front end having a diameter gradually increasing from a front end to a rear end, a rear end having a constant diameter or gradually changing from a front end to a rear end, and a front end and a rear end are provided. Ceramics with excellent wear resistance and seizure resistance in a metal long column drilling device in which a drilling tool having a plug formed of a connection part that changes gradually in diameter and that connects smoothly is connected and fixed to the tip of the core bar Or a plug made of cermet material and having a truncated cone or a cylindrical through hole continuous with the truncated cone sharing the axis of symmetry with the outer shape of the plug, and a cylindrical through hole also sharing the axis of symmetry with the outer shape of the plug A metal rod having a drilling tool, wherein a fixing rod is inserted into both of the through holes, and the fixing rod is fixed to the coupling at an end on the joint side. Drilling equipment .

Further, the plug is made of a cermet material containing at least 50% of at least one of ceramics of carbide, boride and oxide, and the plug has a cross section perpendicular to the axis of symmetry of its outer shape. A metal long pillar drilling device having a divided structure divided into two or more parts.

According to the above-mentioned apparatus, even if the plug is made of a ceramic material or a cermet material, a frustum of a cone sharing a symmetry axis with the outer shape of the plug or a cylindrical plug through hole continuous with the frustum of the plug is provided at one end. After inserting a fixing rod provided with a fixing part at the other end, the plug is connected through a fixing rod to a joint provided with a through hole of a joint sharing a symmetric axis with the outer shape of the plug. By fixing, a drilling tool excellent in wear resistance and seizure resistance can be obtained without practical problems.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

The present inventors have studied various materials as plug materials for preventing wear and seizure of plugs in drilling. As a result, it was found that a ceramic material excellent in wear resistance and seizure resistance and a cermet material in which ceramic and metal were mixed were preferable as plug materials. As the ceramic material, silicon nitride, sialon, alumina, or the like used for structural purposes, or a material reinforced with fiber-like SiC or the like can be used. For cermet materials, TiC, NbC,
50% or more by weight of a ceramic material such as a carbide such as ZrC, HfC or VC, a boride such as TiB ₂ or CrB ₂ or an oxide such as TiO ₂ , ZrO ₂ or Al ₂ O ₃ , and hastelloy or stellite. And a super alloy such as Ni-base or Co-base. The cermet material having a ceramic material content of 50% or more means that the content is 50%.
This is because sufficient seizure resistance cannot be ensured below.

As described above, in the present invention, the entire plug is made of a ceramic material or a cermet material containing 50% or more of ceramics. By the way, as shown in FIG. 7, the plug 1 is generally directly
Or to the metal core 4 via the joint 2. When the whole plug 1 is made of a ceramic material or a cermet material, these materials are generally poor in toughness and brittle in material, so that screw processing is difficult, and in addition, when the screw is tightened, during drilling or after drilling is completed. When a load is applied to the screw portion when the plug is pulled out from the material to be pierced, the screw portion often breaks and becomes unusable.

[0017] In order to avoid such a problem, the present invention provides a tip having a diameter gradually increasing from a tip to a rear end;
A plug having a rear end portion having a constant diameter or gradually changing from a front end to a rear end, and a connecting portion for smoothly connecting the front end portion and the rear end portion with a diameter gradually changing;
A metal long column drilling tool device, which is connected and fixed to a joint 2 for joining a plug to a cored bar 4, wherein the plug has a truncated conical shape which shares a symmetry axis with its outer shape or a truncated conical shape. It is made of ceramic with excellent wear and seizure resistance or a cermet material containing 50% or more of ceramics, and has a locking part at one end and a fixed part at the other end. The plug is connected and fixed to a joint provided with a through hole having a common axis of symmetry with the outer shape of the plug using a fixing rod, and then the plug is connected and fixed to the core metal through the joint.

FIG. 1 is a view for explaining the configuration of a drilling tool according to the present invention. FIG. 1 (a) is a front view of the drilling tool, and FIG.
2 is an NN cross-sectional view of (a). FIG. 2 is an explanatory view of each part of the drilling tool of FIG. 1. FIG. 2 (a-1) is a front view of a plug, and (a-2) is ( a-1) N1-N1 sectional view, (b)
-1) is a front view of the joint, (b-2) is a partially cutaway side view of (b-1), (c-1) is a front view of the fixing rod, (c-
2) is a side view of (c-1).

As shown in FIGS. 2 (a-1) and 2 (a-2), the plug 1 has a truncated conical shape having a maximum diameter d ₁ and a minimum diameter d ₂ centered on the axis of symmetry 6 of the outer shape. A through hole 7 is provided. As shown in FIG. 2 (b-1) and (b-2), the joint 2, a cylindrical through-hole 9 having a diameter d ₃ around the symmetry axis 8 of the periphery are provided. FIG. 2 (c
As shown in -1) and (c-2), the fixing rod 3 connects the plug 1 and the joint 2 to each other through the contact surface 10 with the joint and the contact surface 11 with the plug. When the symmetry axes 6, 8 of the shapes are assembled so as to be linear, they substantially correspond to cylindrical through holes formed by connecting the through holes of the plug 1 and the joint 2 to the truncated cone. It has a shape.

The frustum-shaped portion of the fixed rod is
The length of the fixing rod in the axial direction is set so that when the fixing rod is assembled to the drilling tool, the portion having the maximum diameter does not protrude from the tip of the plug.

As shown in FIG. 1B, when the plug 1 is fixed to the joint 2 via the fixing rod 3, the plug 1 falls off from the fixing rod 3. It has a function of a locking portion K for preventing the operation. On the other hand, the other end of the fixing rod 3 is threaded, and FIG.
As shown in (b), the function of the fixing part F for fastening and fixing the plug 1, the joint 2 and the fixing rod 3 of the drilling tool composed of the plug 1 and the joint 2 joined and fixed via the fixing rod 3. Having. As a means for realizing this fixing function, it is not necessary to use the screws shown here, and other fixing methods may be used as appropriate, such as welding and joining the joint 2 and the fixing rod 3. Regarding the outer diameter of the fixing rod 3, in consideration of the difference in thermal expansion between the fixing rod 3 and the plug 1, when the temperature rises sharply during drilling, the difference in thermal expansion causes the ceramic material or ceramic to be 50% or more. The plug 1 made of the contained cermet material is set so as not to be broken.

The procedure for assembling the parts into the drilling tool device is as follows. First, the fixing bar 3 is inserted from the front end side of the through hole 7 of the plug 1 from the fixing portion F side, and the plug 1 and the fixing bar 3 are assembled. Next, the assembled plug 1 and the fixed rod 3 are inserted into the through hole 9 of the joint 2 from the fixed part F side of the fixed rod 3, and after the plug 1 and the fixed rod 3 and the joint 2 are assembled, the fixed rod 3 is fixed. By tightening the nut 5 into the screw of the fixing portion F of the fixing rod 3, the plug 1
Contact surface 10, between the plug 1 and the joint 2,
Through the frictional force at 11, a drilling tool fixed to the joint 2 and constituted by the plug 1, the joint 2 and the fixing rod 3 is assembled. By fixing the drilling tool assembled as shown in FIG. 1 to the cored bar 4 by a joint method using a screw which is usually used in the above procedure, a ceramic material or a cermet material containing 50% or more of ceramics is fixed. Can be fixed to the metal core 4 without screwing the plug 1 constituted by.

According to the above-mentioned method, the plug 1 and the metal core 4 are connected to each other through the fixing rod 3 and the joint 2 without screwing the plug 1 made of a ceramic material or a cermet material containing 50% or more of ceramics. Can be fixed, and by using a ceramic material or a cermet material containing 50% or more of ceramics for the entire plug 1, wear of the plug 1 can be suppressed, the life of the plug 1 can be improved, and the material to be pierced can be improved. The inner surface quality can be improved.

When the drilling tool has the above structure,
During drilling, a thrust force acts to press the plug 1 against the joint 2, so that the drilling tool does not disassemble.
However, in the drilling step shown in FIGS. 8 and 9, the drilling tool may be forcibly pulled out of the drilled material 12 by moving the cored bar 4 in the axial direction after the drilling is completed. In this case, in the drilling tool having the structure shown in FIG. 1, when the drilling tool is pulled out from the material to be drilled 12, a thrust force acts on the plug 1 so that the plug 1 is pulled out from the fixing rod 3 to the tip end side. Therefore, the locking portion K of the fixing rod 3 may be deformed by the thrust force, the plug 1 may be pulled out from the fixing rod 3, and the drilling tool may be disassembled.

This problem is discussed in, for example, pages 180 to 18 of the “Handbook of Latest Plastic Working” edited by the Japan Society for Plastic Working.
Using the theoretical formula of axially symmetrical pull-out in plastic working described on page 1, the locking portion is designed so that the load required for pulling out the locking portion K is larger than the thrust force generated when pulling out the drilling tool. If the shape of K, that is, the maximum diameter d ₄ and the minimum diameter d ₅ of the locking portion K and the length of the outer shape of the fixing rod 3 of the locking portion K in the direction of the symmetric axis are designed, the drilling tool can be pulled out. Thus, it is possible to prevent the locking portion K of the fixing bar 3 from being damaged. Furthermore, by designing the diameter d ₅ as the yield load of the portion of the cylindrical shape becomes larger than the thrust force generated when withdrawing the drilling tool having a constant diameter d ₅ following the engagement portion K of the fixed rod 3, The drilling tool can be withdrawn from the drilling material without being damaged.

The plug 1 does not necessarily have to have an integral structure as shown in FIG.
As shown in the example of division, a division structure in which the outer shape is divided into two or more portions in a cross section perpendicular to the axis of symmetry may be employed. Further, the boundary between the locking portion K of the fixing rod 3 and the shaft portion G having a constant outer diameter does not necessarily need to be located at the boundary between the plug 1 and the joint 2 as shown in FIG. Each component may be designed inside the plug 1 as shown in FIG. 5 or in the inside of the joint 2 as shown in FIG.

As the material of the joint 2 and the fixing rod 3, for example, tool steel such as SKD61 or stainless steel may be appropriately selected and used.

[0028]

【Example】

(Embodiment 1) An axially symmetric plug shown in FIGS.
A drilling tool consisting of a joint and a fixing rod was manufactured, and a 13Cr steel press roll was drilled under the following conditions. Perforated material: Dimensions 80mm x 80mm x 700m in length
m Drilling material heating temperature: 1230 ° C. Roll hole die diameter: φ93.0 Plug diameter (maximum diameter of plug): 45.5 mm Ceramic and cermet materials were used as plug materials. Table 1 shows the drilling tool shape and material and drilling results. As a binder of the cermet material, Ni-based superalloy Hastelloy C or Stellite which is a Co-based superalloy was used.

[0029]

[Table 1] As is clear from Table 1, when the drilling tool according to the present invention was used, there was no melting or seizure of the plug. That is, it is possible to apply a plug composed entirely of a ceramic material or a cermet material containing 50% or more of ceramics to the drilling of high alloy steel without any practical problem, and it is possible to reduce the wear of the plug and the plug and the material to be rolled. It has become possible to suppress the occurrence of image sticking during the printing.

(Example 2) A drilling tool device shown in FIGS. 1 to 5 and comprising an axially symmetric plug, a joint and a fixing rod was manufactured, and a Mannesmann drilling of SUS316 steel was performed under the following conditions. Table 2 shows the drilling tool shape and material and the drilling results. As a binder of the cermet material, Ni-based superalloy Hastelloy C or Stellite which is a Co-based superalloy was used. Perforated material: Dimensions Diameter 75mm x Length 700mm Perforated material heating temperature: 1200 ° C Minimum roll gap: 68mm Plug diameter (maximum diameter of plug): 60mm

[0031]

[Table 2] As is clear from Table 2, when the drilling tool according to the present invention was used, there was no melting or seizure of the plug. That is, it is possible to apply a plug composed entirely of a ceramic material or a cermet material containing 50% or more of ceramics to the drilling of high alloy steel without any practical problem, and it is possible to reduce the wear of the plug and the plug and the material to be rolled. It has become possible to suppress the occurrence of image sticking during the printing.

[0032]

According to the present invention, it is possible to reduce seizure and plug wear between a plug used in a drilling process of a long metal column and a material to be rolled during drilling, and the inner surface of the material to be drilled can be reduced. Quality and plug life can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a drilling tool according to the present invention;
(A) is a front view, (b) is NN sectional drawing.

FIG. 2 is an explanatory view of each part of the drilling tool according to the present invention;
(A-1) is a front view of the plug, and (a-2) is its N1-
N1 sectional view, (b-1) is a front view of the joint, (b-2)
Is a partially cutaway side view, (c-1) is a front view of a fixed rod,
(C-2) is a side view thereof.

FIG. 3 illustrates another example of the present invention, and is an explanatory diagram in a case where a plug is divided into two parts.

FIG. 4 shows another example of the present invention, and is an explanatory view in a case where a boundary between a locking portion of a fixing rod and a shaft portion having a constant outer diameter is inside a plug.

FIG. 5 shows another example of the present invention, and is an explanatory view in a case where a boundary between a locking portion of a fixing rod and a shaft portion having a constant outer diameter is inside a joint.

FIG. 6 is a diagram illustrating a commonly used plug shape.
(A) is a front view, (b) is a side view.

FIG. 7 is a partially cutaway side view illustrating a generally used punching device.

FIG. 8 is a partially cutaway side view showing the outline of the Mannesmann perforator, viewed from a direction perpendicular to the rolling direction of the roll.

FIG. 9 is a cross-sectional view showing an outline of a press roll punching device in a cross-section including a direction parallel to a rolling direction of a roll and a direction perpendicular to a pass line.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Plug 2 Joint 3 Fixing rod 4 Core metal 5 Nut 6 Symmetry axis of the outer shape of the drilling tool 7 Through hole of the drilling tool 8 Symmetric axis of the outer shape of the joint 9 Through hole of the joint 10 Contact surface between the joint of the plug 11 Joint 12 Contact surface between the plug and the plug 12 Symmetry axis of the external shape of the fixed rod 13 Front end of the split plug 14 Rear end of the split plug 15 Commonly used plug 16 Symmetric axis of the external shape of commonly used plug Reference Signs List 17 Roll of Mannesmann drilling machine 18 Material to be pierced 19 Roll of press roll punching machine 20 Pushing device 21 Pass line A Plug end B Plug rear end Y Plug connection d ₁ Truncated cone provided on drilling tool maximum diameter d ₂ drilled through holes of a truncated cone shape provided on the tool cylindrical diameter d ₄ solid of through holes provided in the minimum diameter d ₃ fitting through-hole of the Screw connection T fitting and the core between the screw connection R plug and the joint between the minimum diameter S plug and the core portion of the frustoconical maximum diameter d ₅ fixing rod portion of the frustoconical bars Screw connection between gold K Locking part of fixed rod G Shaft of fixed rod F Fixed part of fixed rod

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-276910 (JP, A) JP-A-3-165904 (JP, A) Jiko 60-30964 (JP, Y1) (58) Field (Int. Cl. ⁶ , DB name) B21B 25/00 B21B 25/06

Claims (3)

(57) [Claims] 1. A front end having a diameter gradually increasing from a front end to a rear end, a rear end having a constant diameter or gradually changing from a front end to a rear end, and a front end and a rear end having a diameter. A ceramic or cermet material excellent in wear resistance and seizure resistance in a metal long column drilling device in which a drilling tool having a plug formed from a connection portion that is gradually changed and connected is fixed to the tip of a cored bar. A plug having a circular truncated cone or a cylindrical through hole continuous with the truncated cone sharing the axis of symmetry with the external shape of the plug, and a joint having a cylindrical through hole also sharing the axis of symmetry with the external shape. ,
A metal long column drilling device, comprising a drilling tool in which a fixing rod is inserted into both of the through holes, and the fixing rod is fixed to a joint at an end on the joint side and integrated. 2. The metal long column drilling device according to claim 1, wherein the plug is made of a cermet material containing 50% or more in total of at least one of ceramics of carbide, boride and oxide. 3. The metal long column drilling device according to claim 1, wherein the plug has a divided structure divided into two or more portions in a cross section perpendicular to the axis of symmetry of the outer shape.