Body, guide pad, and hole machining tool

Abstract

To provide a body, a guide pad, and a hole machining tool having a guide part capable of suppressing welding due to heat caused by friction during machining, and thereby extending a tool life.SOLUTION: A body 100 of a hole machining tool 10 includes a main body part 110 formed in a cylindrical shape, and a guide part 300 provided on a peripheral part of the main body part 110, in which the guide part 300 has a holding groove 320 formed in the main body part 110 and a rolling element 330 accommodated so as to be rollable in the holding groove 320.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a body, a guide pad, and a hole drilling tool. [Background technology]

[0002] As described in Patent Documents 1 and 2 below, a guide pad is provided in addition to a cutting edge at the tip of the body of a hole-making tool such as a BTA tool or a gun drill. During hole-making, a biased force is applied to the cutting edge, but the guide pad abuts against the inner surface of the hole in the workpiece, suppressing deformation of the body due to the force, and thus enabling high-precision hole-making. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-77679 [Patent Document 2] International Publication No. 2011 / 142370 Summary of the Invention [Problem to be solved by the invention]

[0004] The guide pad ensures the straightness of the hole by sliding against the inner surface of the hole in the workpiece. For this reason, especially when the tool is large in diameter or the workpiece is made of a material that easily retains heat, the heat generated by the burnishing torque (rubbing force) can cause welding, resulting in a short lifespan.

[0005] An object of the present invention is to provide a body, a guide pad, and a hole drilling tool having a guide portion that can suppress welding due to heat generated by friction during drilling and thereby extend the tool life. [Means for solving the problem]

[0006] A body according to one aspect of the present invention is a body of a hole-machining tool, and comprises a cylindrical main body and a guide portion provided on the outer periphery of the main body, and the guide portion has a retaining groove formed in the main body and a rolling element accommodated in the retaining groove so as to be able to roll.

[0007] In a body with the above configuration, the rolling elements of the guide section held in the holding groove of the body roll in contact with the inner surface of the hole in the workpiece during machining. This makes it possible to guide the body against the inner surface of the hole in the workpiece during machining while suppressing welding caused by heat generated by friction, thereby achieving a longer lifespan.

[0008] The rolling elements may be replaceable.

[0009] The retaining groove may extend along the central axis of rotation of the main body, and a plurality of rolling elements may be accommodated and arranged in the retaining groove.

[0010] The rolling element may be formed in a cylindrical shape and held in the holding groove so as to be able to roll around a central axis that is in the same direction as the central axis of rotation of the main body.

[0011] The rolling elements may be formed in a spherical shape.

[0012] A hole drilling tool according to one aspect of the present invention includes the above-described body and a cutting insert attached to the body.

[0013] A guide pad according to one aspect of the present invention is a guide pad that is attached to the outer periphery of the body of a hole drilling tool, and has a base portion with a retaining groove and a rolling element that is accommodated in the retaining groove so that it can roll.

[0014] The rolling elements may be replaceable.

[0015] A plurality of rolling elements may be arranged and housed in a line in the retaining groove.

[0016] The rolling elements may be formed in a cylindrical shape and held in the holding groove so as to be able to roll around the same central axis.

[0017] The rolling elements may be formed in a spherical shape.

[0018] The base portion may be fixed to the body by a fastening part, and the rolling element may be prevented from slipping out of the retaining groove by the fastening part.

[0019] A hole drilling tool according to one aspect of the present invention includes the above-described guide pad, a body to which the guide pad is attached, and a cutting insert attached to the body. [Effects of the Invention]

[0020] According to the present invention, there are provided a body, a guide pad, and a hole drilling tool having a guide portion that can suppress welding due to heat generated by friction during drilling and thereby extend the tool life. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view showing the overall configuration of a hole drilling tool according to a first embodiment. [Figure 2] FIG. 2 is a perspective view of a guide portion provided on the body. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a perspective view of a guide portion according to a modified example. [Figure 5] FIG. 5 is a perspective view showing the overall configuration of a hole drilling tool according to the second embodiment. [Figure 6] FIG. 6 is a perspective view of a guide pad attached to the main body. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicated descriptions will be omitted.

[0023] (First embodiment) First, the configuration of a hole drilling tool 10 according to the first embodiment will be described. The hole drilling tool 10 is a cutting tool for forming a hole in a workpiece (not shown), and is also called a "BTA tool." As shown in Fig. 1, the hole drilling tool 10 includes a body 100 and a cutting insert 200.

[0024] The body 100 is a member that constitutes almost the entire hole drilling tool 10 and is made of steel. The body 100 has a connection part 120. The connection part 120 is a part on one side along the longitudinal direction of the body 100, and is the part that is connected to a drill tube when the body 100 is attached to a machine tool (not shown).

[0025] For ease of explanation, the end of the body 100 where the connection portion 120 is provided will also be referred to as the "base end side" hereinafter. The side opposite the base end side will also be referred to as the "tip end side" hereinafter.

[0026] The body 100 is formed so as to extend linearly from the connecting portion 120 toward the tip side. The body 100 has a substantially cylindrical main body 110, the tip portion of which is formed with a recess 111 by cutting out part of the side surface. A cutting insert 200, which will be described next, is attached to the inner surface of the recess 111.

[0027] The cutting insert 200 is a portion having a cutting edge 210 and is made of cemented carbide. The cutting insert 200 may be made of a material other than cemented carbide. The cutting insert 200 is detachably attached to an insert seat at one longitudinal end of the cartridge by a screw 270 penetrating the cutting insert 200, and the cartridge is fastened and fixed by the screw at a position near the tip end of the inner surface of the recess 111. The cutting edge 210 of the cutting insert 200 protrudes further toward the tip side from the tip of the body 100. When machining a workpiece, the body 100 rotates around the rotation center axis AX1. The rotation direction is indicated by arrow AR1 in FIG. 1. When the body 100 rotates, the cutting edge 210 cuts into the workpiece, cutting it and forming a hole in the workpiece. As described above, the hole drilling tool 10 according to this embodiment is configured as a so-called "cartridge-type" tool in which the cutting insert 200 having the cutting edge 210 and the cartridge are replaceable separate parts. This allows cutting inserts 200 of different shapes to be used by simply replacing the cartridge with one of a different shape. Furthermore, even with cartridges of the same shape, if the periphery of the insert seat in the cartridge is damaged, only the cartridge can be replaced, thereby extending the tool life of the body 100.

[0028] The body 100 is provided with a guide portion 300 on the main body 110. The guide portion 300 abuts against the inner surface of a hole in a workpiece during machining, thereby suppressing vibrations of the body 100. A hole formed in a workpiece by machining using the hole-drilling tool 10 is also referred to as a "machined hole" below. The provision of the guide portion 300 allows machining to be performed while maintaining the straightness and roundness of the machined hole.

[0029] When cutting edge 210 is provided at only one location in the circumferential direction, as in this embodiment, a biased force is applied to hole drilling tool 10 during drilling. Therefore, by providing guide part 300 at a position where this force can be received, deformation of body 100 during drilling can be suppressed, and the straightness and roundness of the drilled hole can be maintained as described above.

[0030] The guide portion 300 is provided on the outer periphery of the main body 110 at a position near the tip end of the body 100. In this embodiment, a total of three guide portions 300 are provided on the main body 110, and these are lined up in the circumferential direction. Note that the number of guide portions 300 provided on the main body 110 may differ from that in this embodiment. For example, one or two guide portions may be provided, or four or more guide portions may be provided.

[0031] A description will now be given of a specific configuration of the guide portion 300. As shown in Figures 2 and 3, the guide portion 300 has a holding groove 320 and a rolling element 330.

[0032] The holding groove 320 is formed in the main body 110. The holding groove 320 extends along the central axis AX1 of rotation of the main body 110. A plurality of rolling elements 330 are provided. In this embodiment, four rolling elements 330 are provided in one guide unit 300. These rolling elements 330 are rotatably housed in the holding groove 320 and are arranged along the central axis AX1 of rotation of the main body 110. The number of rolling elements 330 provided in the guide unit 300 may be different from that in this embodiment. For example, the guide unit 300 may be provided with one rolling element 330.

[0033] The rolling elements 330 are formed in a cylindrical shape and are held in the holding grooves 320 so as to be able to roll around a central axis that is in the same direction as the central axis AX1 of the main body 110.

[0034] The holding groove 320 has a width dimension slightly larger than the outer diameter of the rolling element 330. The holding groove 320 also has protruding portions 321 that protrude toward each other on both edges on the outer periphery of the main body 110, and the groove width at the upper edge is narrower than the diameter of the rolling element 330. This prevents the rolling element 330 housed in the holding groove 320 from slipping out to the outer periphery of the main body 110 in the holding groove 320. The rolling element 330 housed in the holding groove 320 is held in a state where a portion of the rolling element 330 protrudes from the outer periphery of the main body 110 in the holding groove 320.

[0035] The holding groove 320 has a tip opening 322 on the tip side of the main body 110. A bottom 322a of the tip opening 322 is disposed radially outward of the main body 110 relative to the bottom surface 320a of the holding groove 320. For example, the bottom 322a of the tip opening 322 is set to a height that is approximately the same as the center position of the rolling element 330 housed in the holding groove 320. This allows the rolling element 330 to be housed in the holding groove 320 without falling off the tip side of the main body 110. Furthermore, by providing the tip opening 322 in the holding groove 320, the rolling element 330 can be disposed as close to the tip side of the main body 110 as possible, thereby further enhancing the guiding function of the guide unit 300.

[0036] Furthermore, a groove portion 324 is formed in the holding groove 320 on the rear end side of the main body 110. As a result, the holding groove 320 has a rear end opening portion 323 that communicates with the groove portion 324 on the rear end side of the main body 110. A bottom surface 324a of the groove portion 324 is flush with the bottom surface 320a of the holding groove 320. Therefore, the entire rear end opening portion 323 is open at the groove portion 324. Note that the position of the bottom surface 324a of the groove portion 324 may be on the radially inward side of the main body 110 with respect to the bottom surface 320a of the holding groove 320.

[0037] A bridge member 325 is fitted into and attached to the groove 324. The bridge member 325 is formed in a rectangular shape and is fastened and fixed to the main body 110 by a screw 326. By fitting and fixing the bridge member 325 in the groove 324 in this way, the rear end opening 323 of the holding groove 320 is closed. This prevents the rolling element 330 from slipping out of the rear end opening 323, and keeps it housed in the holding groove 320.

[0038] In this guide section 300, the rolling elements 330 are inserted sequentially into the holding groove 320 from the rear end opening 323, and are thereby housed in a state where they are arranged in a line within the holding groove 320. Then, with these rolling elements 330 housed, a bridge member 325 is fitted into the groove section 324, and the bridge member 325 is fixed to the main body 110 with a screw 326, thereby maintaining the rolling elements 330 housed in the holding groove 320 in a rotatable manner.

[0039] By providing the guide part 300 on the body 100, the cylindrical rolling elements 330 of the guide part 300 roll in contact with the inner surface of the hole in the workpiece during machining of the hole drilling tool 10. This suppresses vibrations and the like of the body 100 during machining, allowing machining to be performed while maintaining the straightness and roundness of the machined hole.

[0040] In this way, in the body 100 and hole machining tool 10 equipped with the guide portion 300 having the rolling elements 330, the rolling elements 330 of the guide portion 300 held in the holding groove 320 of the main body 110 abut against and roll on the inner surface of the hole in the workpiece during machining, so that the main body 110 can be guided against the inner surface of the hole in the workpiece during machining while suppressing welding due to heat generated by friction, thereby achieving a longer lifespan.

[0041] Furthermore, since a plurality of rolling elements 330 are accommodated and arranged in the holding groove 320 extending along the central axis of rotation AX1 of the main body 110, the main body 110 can be guided stably and in a balanced manner against the inner surface of the hole in the workpiece.

[0042] Furthermore, with the guide unit 300 having multiple rolling elements 330, even if the groove portion 324 formed in the main body 110 to accommodate the rolling elements 330 in the retaining groove 320 is shortened, a long contact surface can be obtained with the inner circumferential surface of the machined hole in the workpiece. This reduces the volume of the notch in the main body 110, enabling stable guiding without reducing tool rigidity. Furthermore, when replacing worn rolling elements 330, only the worn rolling elements 330 need to be replaced, which is economical. Furthermore, since the mass of each rolling element 330 can be reduced, the rolling elements 330 can be rolled with less force, reducing frictional resistance, which is rolling friction. Furthermore, by periodically changing the positions of the multiple rolling elements 330, each rolling element 330 can be worn evenly, allowing the replacement intervals of each rolling element 330 to be synchronized.

[0043] In the first embodiment, the guide unit 300 having the cylindrical rolling elements 330 has been described, but the rolling elements 330 are not limited to being cylindrical. Next, a guide unit 300A according to a modified example having rolling elements 330 of other shapes will be described. Note that the same components as those in the above configuration example will be assigned the same reference numerals and description thereof will be omitted.

[0044] 4, guide unit 300A according to the modified example is provided with a plurality of spherical rolling elements 330A. In this guide unit 300A, spherical rolling elements 330A are inserted sequentially from rear end opening 323 into holding groove 320, and are thereby housed in holding groove 320 in a state where they are arranged in a line. Then, with these rolling elements 330A housed, bridge member 325 of groove 324 is fitted, and bridge member 325 is fixed to main body 110 with screw 326, thereby maintaining a state in which rolling elements 330A are housed in holding groove 320 so as to be rotatable.

[0045] By providing this guide portion 300A on the body 100, the spherical rolling elements 330A of the guide portion 300A roll in contact with the inner surface of the hole in the workpiece during machining. This suppresses vibrations and other issues in the body 100 during machining, allowing machining to be performed while maintaining the straightness and roundness of the machined hole. In particular, with this guide portion 300A, the spherical rolling elements 330A roll in contact with the inner surface of the hole in the workpiece, thereby reducing the contact area with the inner surface of the hole and further reducing frictional force.

[0046] (Second embodiment) Next, a second embodiment will be described. Note that the same components as those in the first embodiment are given the same reference numerals and the description thereof will be omitted.

[0047] As shown in FIG. 5, the hole drilling tool 20 according to the second embodiment has a guide pad 400 attached to the body 100.

[0048] The body 100 has recesses 114 formed in the main body 110 at intervals in the circumferential direction. The guide pads 400 are attached by being fitted into the recesses 114 of the main body 110. The guide pads 400 are attached to the main body 110 along its central axis of rotation AX1.

[0049] 6, the guide pad 400 has a base portion 410 and rolling elements 430. The base portion 410 is formed in a rectangular shape in a plan view. The base portion 410 is fitted into the recess 114 of the main body 110, and the center portion in the longitudinal direction is fastened and fixed to the main body 110 by a screw (fastening component) 426.

[0050] The base portion 410 has a holding groove 420 on one end side, with the center portion in the longitudinal direction as the boundary. The holding groove 420 extends in the longitudinal direction of the base portion 410. A plurality of rolling elements 430 are provided. In this embodiment, four rolling elements 430 are provided in one guide pad 400. These rolling elements 430 are rotatably housed in the holding groove 420 and are arranged along the longitudinal direction of the base portion 410. Note that the number of rolling elements 430 provided in the guide pad 400 may differ from that in this embodiment. For example, the guide pad 400 may be provided with one rolling element 430.

[0051] The rolling elements 430 are formed in a cylindrical shape. When the guide pad 400 is attached to the main body 110, the rolling elements 430 are held in the holding grooves 420 so as to be able to roll around a central axis that is in the same direction as the central rotation axis AX1 of the main body 110.

[0052] The holding groove 420 has a width dimension slightly larger than the outer diameter of the rolling element 430. Furthermore, the holding groove 420 has protruding portions 421 on both edges on the upper side that protrude toward each other, and the groove width at the upper edge is narrower than the diameter of the rolling element 430. This prevents the rolling element 430 housed in the holding groove 420 from slipping out of the upper part of the holding groove 420. The rolling element 430 housed in the holding groove 420 is held in a state where a portion of the rolling element 430 protrudes from the upper surface of the holding groove 420.

[0053] The holding groove 420 has a tip opening 422 on the end side. A bottom 422a of the tip opening 422 is positioned closer to the upper surface of the base portion 410 than the bottom surface of the holding groove 420. For example, the bottom 422a of the tip opening 422 is set to a height approximately equal to the center position of the rolling element 430 housed in the holding groove 420. This allows the rolling element 430 to be housed in the holding groove 420 without falling off the end side of the base portion 410. Furthermore, by providing the tip opening 422 in the holding groove 420, when the guide pad 400 is attached to the main body 110 of the body 100, the rolling element 430 can be positioned as close to the tip side of the main body 110 as possible, thereby further improving the guiding function of the guide pad 400.

[0054] Furthermore, a countersunk hole 424 is formed on the central side of the base portion 410. As a result, the holding groove 420 has a rear end opening 423 that communicates with the countersunk hole 424 on the central side of the base portion 410. A bottom surface 424a of the countersunk hole 424 is flush with the bottom surface of the holding groove 420. Therefore, the entire rear end opening 423 is open at the countersunk hole 424. Note that the bottom surface 424a of the countersunk hole 424 may be located lower on the base portion 410 than the bottom surface of the holding groove 420.

[0055] A screw 426 that fastens and fixes the guide pad 400 to the main body 110 is inserted into the counterbore 424. In this way, by inserting the screw 426 into the counterbore 424 and fixing the guide pad 400 to the main body 110, the rear end opening 423 of the holding groove 420 is sealed. This prevents the rolling element 430 from slipping out of the rear end opening 423, and keeps it housed in the holding groove 420.

[0056] In this guide pad 400, the rolling elements 430 are inserted sequentially from the rear end opening 423 into the holding groove 420, and are thereby accommodated in a state where they are arranged in a line within the holding groove 420. Then, with these rolling elements 430 accommodated, the guide pad 400 is fitted into the recess 114 of the main body 110, and a screw 426 inserted into the counterbore 424 of the base portion 410 is screwed into a female thread (not shown) formed in the main body 110 to fix the guide pad to the main body 110, thereby maintaining the rolling elements 430 rotatably accommodated in the holding groove 420. Furthermore, in the guide pad 400, the screw 426 prevents the rolling elements 430 from coming out of the holding groove 420, so that a separate piece for preventing the rolling elements 430 from coming out is not required, and the number of parts can be reduced.

[0057] By providing the guide pad 400 on the body 100, the cylindrical rolling elements 430 of the guide pad 400 roll on the inner surface of the hole in the workpiece during machining of the hole machining tool 20. This suppresses vibrations and the like of the body 100 during machining, and enables machining to be performed while maintaining the straightness and roundness of the machined hole.

[0058] In this way, in the hole machining tool 20 equipped with the guide pad 400 having the rolling element 430, the rolling element 430 held in the holding groove 420 of the guide pad 400 abuts and rolls against the inner surface of the hole in the workpiece during machining, so that the body 100 can be guided against the inner surface of the hole in the workpiece during machining while suppressing welding due to heat generated by friction, thereby achieving a longer lifespan.

[0059] Moreover, since the plurality of rolling elements 430 are accommodated and arranged in a line in the holding groove 420, the body 100 can be guided stably and in a well-balanced manner against the inner surface of the hole in the workpiece.

[0060] Furthermore, guide pad 400 having multiple rolling elements 430 is economical because when worn rolling elements 430 need to be replaced, only the worn rolling elements 430 need to be replaced. Furthermore, the mass of each rolling element 430 can be reduced, allowing the rolling elements 430 to roll with less force, thereby reducing frictional resistance, which is rolling friction. Furthermore, by periodically changing the positions of the multiple rolling elements 430, each rolling element 430 can be worn evenly, and the replacement times for each rolling element 430 can be synchronized.

[0061] In the second embodiment, the guide pad 400 having the cylindrical rolling elements 430 has been described, but the rolling elements 430 are not limited to being cylindrical and may be, for example, spherical. If the rolling elements 430 are spherical, the contact area with the inner surface of the hole in the workpiece can be made smaller, and the frictional force can be further reduced.

[0062] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Design modifications to these specific examples made by a person skilled in the art as appropriate are also included within the scope of the present disclosure as long as they comprise the features of the present disclosure. The elements of the above-described specific examples, as well as their arrangement, conditions, shape, etc., are not limited to those exemplified and can be modified as appropriate. The elements of the above-described specific examples can be combined in various ways as appropriate, as long as no technical contradictions arise. [Explanation of symbols]

[0063] 10,20 Hole drilling tools 100 Body 110 Main Unit 200 cutting inserts 300,300A guide part 320,420 Retaining groove 330, 330A, 430 rolling elements 400 Guide Pad 410 Base 426 Screws (fastening parts) AX1 Rotational axis

Claims

1. A body of a hole drilling tool, A cylindrically formed main body; a guide portion provided on an outer periphery of the main body; Equipped with The guide portion is a retaining groove formed in the main body; a rolling element rollably accommodated in the holding groove; having body.

2. The rolling elements are replaceable. The body of claim 1 .

3. The retaining groove extends along the rotational axis of the main body, A plurality of the rolling elements are arranged and housed in the retaining grooves. The body of claim 1 .

4. The rolling element is formed in a cylindrical shape and is held in the holding groove so as to be able to roll around a central axis in the same direction as the central axis of rotation of the main body. The body of claim 1 .

5. The rolling elements are formed in a spherical shape. The body of claim 1 .

6. A body according to any one of claims 1 to 5; a cutting insert attached to the body; Equipped with Hole drilling tool.

7. A guide pad attached to an outer periphery of a body of a hole drilling tool, a base portion having a retaining groove; a rolling element rollably accommodated in the holding groove; having Guide pad.

8. The rolling elements are replaceable. The guide pad according to claim 7.

9. A plurality of the rolling elements are arranged in a line and housed in the retaining groove. The guide pad according to claim 7.

10. The rolling elements are formed in a cylindrical shape and are held in the holding grooves so as to be able to roll around the same central axis. The guide pad according to claim 7.

11. The rolling elements are formed in a spherical shape. The guide pad according to claim 7.

12. the base portion is fixed to the body by a fastening part; The rolling element is prevented from coming out of the holding groove by the fastening component. The guide pad according to claim 7.

13. A guide pad according to any one of claims 7 to 12; a body to which the guide pad is attached; a cutting insert attached to the body; Equipped with Hole drilling tool.

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