JP2014083662A - Drilling device and drilling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a deep hole in a workpiece and carry out an operation for chamfering the circumference of an end part of the deep hole, in one process without causing complication of a device nor complexity of processes.SOLUTION: A drilling device includes: a working device body 10 which has a main spindle O and a drill 12 to be mounted along the main spindle and to be used for forming a deep hole, and is capable of rotating and feeding the drill 12; a clamp device 15 for supporting a workpiece 20 along the main spindle O; and a guide bush 16 for guiding a tip of the drill 12. An engaging part 22 is provided on a rear end side of a drill body 21. A connection part 33 with which the engaging part 22 is engaged to establish connection with the drill 12 is provided in a guide bush body 31. At the point of time when the engaging part 22 is engaged with the connection part 33 to connect the guide bush 16 and the drill 12 to each other, the guide bush 16 rotates together with the drill 12, so that an end part of the workpiece 20 is chamfered by a chamfering blade 32 of the guide bush body 31.

Description

  The present invention relates to a drilling apparatus and a drilling method for applying a guide bush to make a deep hole in a workpiece.

  When manufacturing seamless steel pipes by piercing and rolling material billets, from the viewpoint of preventing unevenness of the steel pipe after rolling, reducing plug wear, and preventing biting troubles at the initial stage of piercing and rolling. A technique (for example, Patent Document 1) that punches the end of the material billet is known.

  When performing such drilling, if a long drill is used in the drilling device, the drill may swing greatly at the start of processing, and a guide bush is used to prevent such swinging (for example, Patent Document 2). ).

  By the way, the formation of deep holes in the material billet and the punching and hole machining on the tip of the material billet have conventionally been performed in separate steps using separate tools, and considering production efficiency It is difficult to take time to change tools. Moreover, in order to perform these processes, the number of processing apparatuses increases, and installation space and cost increase. Therefore, there is a demand for performing these steps in one step with one processing apparatus.

  As a technique for performing two types of hole processing at the same time, for example, a technique for forming a two-stage hole by increasing the base processing diameter of a drill tool has been proposed (for example, Patent Document 3). Further, a technique has been proposed in which a chamfering tool is externally attached to a drill shaft, a hole is formed by a drill, and then chamfered (for example, Patent Document 4). Further, a technique has been proposed in which a chamfering blade is built in a drill shaft, a hole is formed by a drill, and then the chamfering blade is projected to perform chamfering (for example, Patent Document 5).

JP 2002-001403 A JP 2005-125450 A JP 08-168912 A JP-A-11-254218 Japanese Patent Laid-Open No. 2001-322019

  However, if the technique of thickening the base of the drill tool or externally attaching a chamfering blade as shown in Patent Documents 3 and 4 is applied to the drilling device for forming the deep hole, the guide bush This prevents the chamfering blade attached to the thick part of the base or the drill shaft from reaching the billet end face. Therefore, a mechanism for removing the guide bush is required, which complicates the equipment and makes the process complicated.

  On the other hand, with the technique of incorporating a chamfering blade in the drill shaft as shown in Patent Document 5, the strength of the drill shaft is reduced and it is difficult to apply it to a deep hole. Moreover, since the guide bush exists adjacent to the billet end face, the chamfering blade cannot be projected at the billet end face. For this reason, the mechanism which removes a guide bush or moves to a fundamental side is needed, an installation will become complicated and a process will become complicated.

  The present invention has been made in view of such circumstances, and the operation of forming a deep hole in a workpiece and chamfering the periphery of the end portion leads to complication of the apparatus and complexity of the process. It is an object of the present invention to provide a drilling apparatus and a drilling method that can be performed in a single step without any problems.

  In order to solve the above-described problems, the present invention includes a processing apparatus main body having a main shaft and a drill for forming a deep hole to be mounted along the main shaft, and capable of rotating and feeding the drill. A workpiece supporting portion for supporting a material; and a guide bush provided at a distal end portion of the workpiece supported by the workpiece supporting portion for guiding the distal end of the drill. A guide main body having a guide hole for guiding the drill; and a guide bush main body, the guide bush having a guide hole for guiding the drill. A chamfering blade attached to an end of the workpiece on the workpiece side, and a coupling portion that engages with the engagement portion to establish a coupling with the drill, and is rotatable and moved along the main shaft Is possible, When a deep hole of a predetermined length is formed in the workpiece by the drill, and when the engagement portion of the drill is engaged with the coupling portion of the guide bush and the guide bush and the drill are coupled, Provided is a drilling apparatus characterized in that the guide bush rotates together with the drill, and the chamfering blade that rotates along with the drill performs chamfering around the entrance of the deep hole at the end of the workpiece.

  It is preferable to further include a guide member that guides the guide bush so as to be rotatable and movable in the main axis direction. The guide bush may be slidably fitted inside the guide member.

  Further, the engaging portion is provided as a stepped portion that protrudes from the peripheral surface of the drill body, and the coupling portion is provided as a protruding portion at a rear end portion of the guide bush. can do.

  The present invention also includes a drill having a main shaft and a deep hole for forming a deep hole to be mounted along the main shaft, a processing apparatus main body capable of rotating / feeding the drill, and a workpiece that supports a workpiece. A drill body having a long shape, and a guide bush provided at a tip portion of the workpiece supported by the workpiece support portion and guiding the tip of the drill; And an engaging portion formed on the rear end side of the drill body, the guide bush including a guide bush body having a guide hole for guiding the drill, and a work piece side of the guide bush body. A chamfering blade attached to the end portion and a coupling portion that engages with the engagement portion to establish a coupling with the drill, and is provided so as to be rotatable and movable along the main shaft. Depending on the processing equipment A drilling method for performing a drilling process, wherein a deep hole is formed in a workpiece by the drill, and when the drill forms a deep hole to a predetermined position, the engaging portion is a coupling portion of the guide bush. The guide bush and the drill are coupled to each other so that the guide bush rotates together with the drill, and the deep hole inlet at the end of the workpiece is rotated by the chamfering blade that rotates with the drill. Provided is a drilling method characterized by chamfering the periphery.

  According to the present invention, the drill has an engaging portion formed on the rear end side of the drill main body, the guide bush has a guide bush main body having a guide hole for guiding the drill, and the workpiece bush side of the guide bush main body. A chamfering blade attached to the end of the shaft, a coupling portion that engages with the engagement portion to establish a coupling with the drill, and the guide bush is provided to be rotatable and movable along the main shaft When the drill forms a deep hole of a predetermined length in the work piece, and the engaging portion of the drill is engaged with the coupling portion of the guide bush and the guide bush and the drill are coupled, the guide bush is A chamfering blade that rotates together with the drill is chamfered around the deep hole at the end of the workpiece by a chamfering blade that rotates with the drill. Therefore, the operation of forming a deep hole in the workpiece and chamfering the periphery at the end thereof can be performed in a single step without incurring the complexity of the apparatus and the complexity of the process. For this reason, processing time can be shortened compared with the case where deep hole processing and chamfering processing are performed by performing tool exchange.

It is a side view which shows the drilling apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows the clamp apparatus used for the drilling apparatus which concerns on one Embodiment of this invention. It is a front view which shows the guide bush and guide block which are used for the drilling apparatus which concerns on one Embodiment of this invention. It is a side view which shows the drilling apparatus which concerns on other embodiment of this invention. It is a figure for demonstrating the process at the time of drilling with the drilling apparatus which concerns on one Embodiment of this invention. It is a figure which shows the to-be-processed material in which the deep hole and the chamfering part were formed by the drilling apparatus which concerns on one Embodiment of this invention. It is a figure which shows the state which applied the perforated plug to the chamfering process part of the raw material billet for seamless steel pipes used as a workpiece.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a side view showing a drilling device according to an embodiment of the present invention, FIG. 2 is a schematic view showing the clamping device, and FIG. 3 is a front view showing guide bushes and guide blocks.

  The drilling device 1 has a main shaft (processing shaft) O and a quill 11 serving as a mounting portion for mounting a drill along the main shaft, a drill 12 mounted on the quill 11, and rotating / feeding the mounted drill 12. It has a possible processing device body 10. The apparatus main body 10 includes a spindle head 13 having a rotation drive unit that rotates the quill 11, and a feed mechanism 14 that moves the spindle head 13 along the spindle O and sends the drill 12.

  Further, the drilling device 1 includes a clamp device 15 that clamps a round bar-shaped workpiece (workpiece) 20, a guide bush 16 provided at the center of the workpiece 20 on the processing end side (tip portion), and a guide bush. 16 and a fixed guide block 17 that guides the guide bush 16.

  As the workpiece 20, a billet of seamless steel pipe can be used. In this case, the shaft core portion of the material billet is drilled for the purpose of preventing uneven thickness of the steel pipe after rolling. However, the workpiece 20 is not limited to such a material billet, and is not limited to a round bar shape.

  The drill 12 is for forming a deep hole in the workpiece 20, and is provided as a long drill body 21 and a stepped portion protruding from the peripheral surface of the drill body 21 on the rear end side of the drill body 21. And a plurality of engaging portions 22. The drill body 21 is formed with a chip discharge groove 21a along the longitudinal direction thereof.

  As shown in FIG. 2, the clamping device 15 includes an upper lift V block 15 a and a lower fixed V block 15 b, and clamps the workpiece 20 by lowering the lift V block 15 a. The workpiece 20 is fixed so that the longitudinal direction coincides with the main axis O. It may be sandwiched between V blocks from the left and right.

  The guide bush 16 is slidably fitted inside the fixed guide block 17, is guided by the fixed guide block 17, is rotatable and movable along the main shaft O, and is fitted to the machining diameter of the drill 12. A guide bush main body 31 having a guide hole 19 having an inner diameter, a chamfering blade 32 provided on the work-side surface of the guide bush main body 31, a rear end portion of the guide bush main body 31, and an engaging portion 22 And a plurality of coupling portions 33 that are engaged to establish a coupling with the drill 12. For example, as shown in FIG. 3, the chamfering blade 32 is provided at two places on the end surface of the guide bush main body 31. The number of chamfering blades is not particularly limited, but two or more are preferred.

  Note that the fixed guide block 17 is not limited to the guide bush 16 slidably guided, and may have other guide mechanisms such as a ball spline.

  The engagement portion 22 of the drill 12 may be fixedly provided on the drill body 21 when the hole depth dimension of the deep hole is constant, but when a plurality of hole depths are set, For example, it is preferable to provide a plurality of bolt holes in the drill body 21 so that the position of the engaging portion 22 can be adjusted in accordance with the hole depth.

When the engaging portion 22 is engaged with the coupling portion 33, the guide bush 16 and the drill 12 are coupled, the rotational power of the drill 12 is transmitted to the guide bush 16, the guide bush 16 is rotated, and the chamfering blade 32. Chamfering operation is possible. The coupling portion 33 can be constituted by a protrusion, and the guide bush 16 and the drill 12 can be coupled by the engagement portion 22 being caught. When the engagement portion 22 contacts the coupling portion 33, it is preferable that the rotation of the drill 12 is slowed down or stopped in order to avoid wear of the contact portion. Further, it is preferable that the engaging portion 22 is brought into contact with the coupling portion 33 after being shifted in the circumferential direction.
In this case, the positional relationship between the projection (joint portion 33) of the guide bush 16 and the stepped portion (engagement portion 22) of the drill 12 is such that the chamfering blade 32 is aligned with the position of the chip discharge groove 12a of the drill 12. Good positional relationship.

In addition, it is preferable that the contact portion of the engaging portion 22 and the coupling portion 33 constitute an appropriate power transmission mechanism such as a gear transmission mechanism such as a ratchet. It is more preferable to use a so-called synchro mechanism, friction clutch mechanism, or the like that meshes with a rotating gear as a power transmission mechanism so that both can easily mesh with each other while the drill 12 is rotated.
In this case, since the positional relationship between the chamfering blade 32 and the chip discharge groove 12a becomes irregular, it is preferable to provide a gap between the end face of the workpiece 20 and the end face of the guide bush 16 so that the chips are discharged reliably. .

  As the chamfering blade 32, for example, a chamfering blade having a 45 ° angle with respect to the ridgeline of the machining hole entrance is generally used. It may be a curve that matches the angle of the tangent line that contacts the inlet or the tip shape of the perforated plug.

  The guide bush 16 can be rotated and moved along the main axis O inside the fixed guide block 17. However, as shown in FIG. 4, the guide bush 16 does not come out of the fixed guide block 17 when the drill 12 is pulled out after processing. Thus, it is preferable to provide the stopper 35. Further, it is preferable that the guide bush 16 is pulled back by an elastic member such as a spring so that the guide bush 16 is easily detached from the end face of the workpiece 20 after the processing is completed.

  Next, a method for drilling by the drilling apparatus having the above configuration will be described with reference to FIG.

  First, after the workpiece 20 is inserted into the clamping device 15 by a conveyance roller (not shown) and stops at the fixed guide block 17, the conveyance roller descends, and the round bar-shaped workpiece 20 is moved to the fixed V block 15 b of the clamping device 15. Sit down. In this state, the work 20 is fixed and centered in the horizontal direction by lowering the elevating V-block 15a of the clamp device 15. Then, as shown in FIG. 5 (a), the drill 12 is inserted into the guide hole 19 of the guide bush 16, and the tip of the drill 12 is in contact with the center of the workpiece 20 on the processing end side (tip end). Drilling is started by rotating the drill 12.

  As shown in FIG. 5B, the drill 12 is fed along the main axis O while the drill 12 is rotated, and the deep hole is dug. Further, when the engaging portion 22 of the drill 12 engages with the coupling portion 33 of the guide bush 16 as shown in FIG. 5C, the guide bush 16 and the drill 12 are coupled, and the guide bush 16 Rotates along with the drill 12 while being guided by the fixed guide block 17 and moves along the main axis O, and the chamfering blade 32 chamfers the periphery of the deep hole at the end of the workpiece 20. Then, as soon as the drill 12 reaches the end of the deep hole machining, the chamfering with the chamfering blade 32 is finished, and the drilling is finished.

  Thereby, as shown in FIG. 6, the deep hole 51 and the chamfering process part 52 of the edge part are formed in the workpiece | work 20. As shown in FIG. When the workpiece 20 is a material billet for a seamless steel pipe, the tip of the perforated plug 55 comes into contact with the chamfered portion 52 as shown in FIG.

  According to the present embodiment, the drill 12 has an engaging portion 22 formed on the rear end side of the drill body 21, and the guide bush 16 includes a guide bush body 31 having a guide hole 19 for guiding the drill 12, and The guide bush main body 31 has a chamfering blade 32 attached to the end portion on the workpiece 20 side, a coupling portion 33 that engages with the engagement portion 22 and establishes a coupling with the drill 12, and the guide bush 16 is , It is slidable inside the fixed guide block 17, is guided by the fixed guide block 17, and can rotate and move along the main axis O, so that a deep hole of a predetermined length is formed in the workpiece 20 by the drill 12. After being formed, the engagement portion 22 of the drill 12 is engaged with the coupling portion 33 of the guide bush 16, and the guide bush 16 rotates together with the drill 12 to process the deep hole to the end. At the same time, chamfering the periphery of the deep hole at the end of the workpiece 20 by the chamfered blade 32. Therefore, the operation of forming a deep hole in the work 20 and chamfering the periphery of the work 20 can be performed in a single step without causing complication of the apparatus and complexity of the process. For this reason, processing time can be shortened compared with the case where deep hole processing and chamfering processing are performed by performing tool exchange.

  In addition, when the workpiece 20 is a material billet for seamless steel pipe, chamfering can reduce the trouble of biting failure at the beginning of piercing and rolling, and uneven thickness at the end of the seamless steel pipe can be reduced. Can be improved.

Next, examples of the present invention will be described.
Here, a case where a deep hole is formed in a material billet for a seamless steel pipe and chamfering is performed will be described.

  Before inserting the material billet into the heating furnace, a drilling device was used to drill the center of the billet end face at a depth of 8 times the hole diameter.

  The drill used has an effective machining depth of 1.1 times the hole depth, provided with a chip discharge groove and provided with a guide pad at the tip portion, and a base side outer peripheral surface of the main body, It was assumed to have four stepped portions (engagement portions) provided in the circumferential direction while avoiding the chip discharge groove.

  The guide bush has a cylindrical main body with an inner diameter (guide hole diameter) of 1.01 times, an outer diameter of 1.3 times and a depth of twice the drilling hole diameter, and one end face of the main body. Along a pair of (two) chamfering blades with an effective chamfering width of 0.3 times the drilled hole diameter and the end face on the opposite side of the main unit (processing device main unit side) along the circumferential direction. And eight protruding portions (joining portions) provided. The fixed guide block was provided with a guide bush mounting hole 1.001 times larger than the outer diameter of the guide bush, and the guide bush was mounted in the mounting hole.

  Also, when pulling out the drill from the billet, install a spring that returns the guide bush, and to prevent the guide bush from popping out to the machine body when pulling out the drill from the guide bush, A stopper was provided.

  By using the drilling device as described above, the end face where the material billet is first deeply drilled was brought into contact with the fixed guide block, and the material billet was fixed by the clamping device. Then, the drill was inserted into the guide bush in the fixed guide block, and was put on standby immediately before the tip of the drill contacted the material billet while rotating the drill. The feed mechanism feeds the drill to the billet side, and the guide pad at the tip of the drill supports the guide bush, and the guide bush supports the fixed guide block. It was. The rotating drill was fed into the billet, and the machining feed was advanced with the guide pad at the tip of the drill supported by the inner wall of the machining hole of the billet.

  Before the drilling of the drill reaches a predetermined hole depth and immediately before the start of chamfering blade processing, the rotation of the drill is stopped, and in this state, two stepped portions (engagement portions) of the drill However, the positions of the guide bushes were adjusted so as to fit between the two protrusions (joint portions), and the guide bushes were slid to the base side of the drill to engage the two. Specifically, the stepped portion (engagement portion) of the drill and the protrusion (joint portion) of the guide bush are tapered so as to face each other in the machining axis direction, and the tapered slope when both are slid and approached As a result of the force along, each of them was relatively rotated in the circumferential direction, and the stepped portion and the protruding portion could be engaged with each other without difficulty. In addition, if the synchro mechanism of the principle close | similar to this is used, it is also possible to slide a step part in a projection part, rotating a drill.

  When the stepped part of the drill and the protrusion of the guide bush are engaged, the rotation of the drill is resumed. The stepped part of the drill is pressed against the protrusion of the guide bush to transmit the thrust of the drill to the chamfering blade. At the same time, the chamfering process was terminated.

  In this way, it was confirmed that the time can be reduced by 32% compared to the prior art by performing the deep hole machining and the chamfering machining in one step without changing tools.

  The billet subjected to deep hole machining and chamfering in this way was charged in a heating furnace and heated, and the heated billet was extracted, and a seamless steel pipe was manufactured through rolling with a perforated plug. The uneven thickness at the end of the steel was improved from 15% to 5%, and the chamfering process doubled the life of the pierced plug and halved the trouble of biting failure at the beginning of piercing and rolling.

  The present invention is effective when performing deep hole machining and chamfering on the material billet end face of a seamless steel pipe, but is not limited to this, in addition to deep hole machining that generally requires a guide bush, This is effective in general when machining is required.

DESCRIPTION OF SYMBOLS 1 Drilling apparatus 10 Processing apparatus main body 11 Quill (mounting part)
12 Drill 13 Spindle Head 14 Feeding Mechanism 15 Clamp Device 16 Guide Bush 17 Fixed Guide Block 19 Guide Hole 20 Workpiece (Workpiece)
21 Drill body 22 Engagement section 31 Guide bush body 32 Chamfering blade 33 Coupling section 35 Stopper 51 Deep hole 52 Chamfering section 55 Drilling plug

Claims (5)

A processing apparatus main body having a main shaft and a drill for forming a deep hole to be mounted along the main shaft, and capable of rotating and feeding the drill;
A workpiece support portion for supporting the workpiece;
A guide bush provided at the tip of the workpiece supported by the workpiece support and guiding the tip of the drill;
The drill has a long drill body, and an engagement portion formed on the rear end side of the drill body,
The guide bush includes a guide bush main body having a guide hole for guiding the drill, a chamfering blade attached to an end of the guide bush main body on the workpiece side, and the engagement portion is engaged with the guide bush main body. A coupling portion that establishes a coupling with the drill, and is provided to be rotatable and movable along the main axis,
When a deep hole of a predetermined length is formed in the workpiece by the drill, and when the engagement portion of the drill is engaged with the coupling portion of the guide bush and the guide bush and the drill are coupled, A drilling apparatus characterized in that the guide bush rotates together with the drill and the chamfering blade that rotates along with the drill performs chamfering around the entrance of the deep hole at the end of the workpiece.   The drilling apparatus according to claim 1, further comprising a guide member that guides the guide bush so as to be rotatable and movable in a main axis direction.   The drilling device according to claim 2, wherein the guide bush is slidably fitted inside the guide member.   The engaging portion is provided as a stepped portion that protrudes from the peripheral surface of the drill body, and the coupling portion is provided as a protruding portion at a rear end portion of the guide bush. The drilling device according to any one of claims 1 to 3. A machining apparatus main body having a main shaft and a drill for forming a deep hole to be mounted along the main shaft, capable of rotating and feeding the drill, a work material support portion for supporting the work material, A guide bush provided at the tip of the workpiece supported by the workpiece support and guiding the tip of the drill; the drill having a long drill shape; and the drill body An engaging portion formed on a rear end side of the guide bush, and the guide bush is attached to a guide bush main body having a guide hole for guiding the drill, and an end of the guide bush main body on the workpiece side. Drilling is performed by a drilling device provided with a chamfering blade and a coupling portion that engages with the engagement portion to establish a coupling with the drill and that is rotatable and movable along the main shaft. The line A drilling method,
When the drill forms a deep hole in the workpiece, and the drill forms a deep hole up to a predetermined position, the engagement portion is engaged with the coupling portion of the guide bush, and the guide bush and the drill And thereby the guide bush rotates together with the drill, and the chamfering blade that rotates with the drill performs chamfering around the entrance of the deep hole at the end of the workpiece. Drilling method.

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