Guide pad, body and tool for drilling

Abstract

To provide a guide pad which is usable over a long period of time, a body mounted with the guide pad, and a tool for drilling where the guide pad is provided in the body.SOLUTION: A guide pad includes a contact surface 310 which is brought into contact with bottom surfaces 113 of recesses 114A, 114B and 114C of a body 100, and a guide surface provided on an exposure surface 320 on a side opposite to the contact surface 310, wherein in the exposure surface 320, a first guide surface 321, a third guide surface 323 and a fifth guide surface 325 or a second guide surface 322, a fourth guide surface 324 and a sixth guide surface 326, which are formed in circular arcuate shapes in a cross-sectional view and have different central positions of the circular arc, are arranged in parallel with each other in a rotation direction AR1 during processing, and during the processing, the one of the first guide surface 321, the third guide surface 323 and the fifth guide surface 325 or the one of the second guide surface 322, the fourth guide surface 324 and the sixth guide surface 326 is brought into contact with the inner surface of the hole.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] As described in the following Patent Documents 1 and 2, a guide pad is provided in addition to a cutting edge at the tip of the body of a hole-machining tool such as a BTA tool or a gun drill. During hole machining, a force is applied to the cutting edge in a biased direction, but the guide pad abuts against the inner surface of the hole in the workpiece and suppresses deformation of the body caused by the force, making it possible to perform high-precision hole machining. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-77679 A [Patent Document 2] JP 2014-30854 A Summary of the Invention [Problem to be solved by the invention]

[0004] Guide pads are consumables that wear out due to friction with the inner surface of the hole, so they need to be replaced with new ones periodically. In order to reduce processing costs, it is preferable to change the orientation of a guide pad after use and reattach it to the body so that one guide pad can be used multiple times.

[0005] An object of the present invention is to provide a guide pad that can be used over a long period of time, a body to which the guide pad is attached, and a hole drilling tool having a body on which the guide pad is provided. [Means for solving the problem]

[0006] A guide pad according to one embodiment of the present invention is a guide pad used in a hole machining tool, and comprises a contact surface that contacts the bottom surface of a mounting seat of the body of the hole machining tool, and a guide surface that is provided on an exposed surface opposite the contact surface and abuts against the inner surface of the hole during machining, and the exposed surface has three or more guide surfaces that are formed in an arc shape in cross section and have different center positions, and are arranged in parallel along the rotation direction during machining, and one of the three or more guide surfaces is configured to abut against the inner surface of the hole during machining.

[0007] In the guide pad having the above configuration, three or more guide surfaces, which are arc-shaped in cross section and come into contact with the inner surface of the hole in the workpiece during machining, are arranged in parallel along the rotation direction during machining. Each time one guide surface wears out, the guide pad is reassembled to the body so that another guide surface comes into contact with the inner surface of the hole, allowing one guide pad to be used repeatedly.

[0008] Two sets of three or more guide surfaces each having a circular arc with a center position different from each other may be provided on the exposed surface at point symmetric positions.

[0009] The three or more guide surfaces having arcs with different center positions may have the same radius of curvature of the arcs.

[0010] The three or more guide surfaces having different central positions of the arcs may have different radii of curvature of the arcs.

[0011] A body according to one embodiment of the present invention is a body for a hole machining tool having three or more mounting seats spaced apart circumferentially, with guide pads attached to each of these mounting seats, wherein the bottom surfaces of the mounting seats are flat, and when viewed from the tip in the direction of the central axis of rotation, the bottom surfaces of at least two of the mounting seats are inclined with respect to the second reference line, when a line passing through the midpoint of the bottom surface of the mounting seat and the central axis of rotation is defined as a first reference line, and a line passing through the midpoint and perpendicular to the first reference line is defined as a second reference line, the inclination directions around the midpoint with respect to the second reference line are opposite to each other, and the bottom surface of at least one of the mounting seats may not be inclined with respect to the second reference line.

[0012] The mounting seat may have a diameter determining guide mounting seat arranged on the opposite side of the rotation center axis from the mounting location of the cutting insert, a bearing guide mounting seat arranged forward in the rotation direction from the diameter determining guide mounting seat, and an auxiliary guide mounting seat arranged rearward in the rotation direction from the diameter determining guide mounting seat.

[0013] The bearing guide mounting seat and the auxiliary guide mounting seat may be disposed on opposite sides of the central axis of rotation, shifted forward or backward from each other in the direction of rotation.

[0014] The bottom surface of the mounting seat may be inclined with respect to the central axis of rotation so as to move away from the central axis of rotation toward the tip.

[0015] A hole machining tool according to one embodiment of the present invention is a hole machining tool comprising a plurality of guide pads and a body having a mounting seat on which the guide pads are attached, wherein the guide pads have an abutment surface which abuts against the bottom surface of the mounting seat of the body, and a guide surface which is provided on an exposed surface opposite the abutment surface and abuts against the inner surface of the hole during machining, and the exposed surface has three or more guide surfaces which are formed in an arc shape in cross section and have different center positions, and which are arranged in parallel along the rotation direction during machining, and wherein one of the three or more guide surfaces is configured to abut against the inner surface of the hole during machining.

[0016] The exposed surface of the guide pad may be provided with two sets of three or more guide surfaces each having a circular arc with a different central position, the sets being positioned symmetrically with respect to a point.

[0017] The three or more guide surfaces of the guide pad having different central positions of the circular arcs may have the same radius of curvature of the circular arcs.

[0018] The three guide surfaces of the guide pad having different central positions of the circular arcs may have different radii of curvature of the circular arcs.

[0019] The body is provided with three or more mounting seats spaced circumferentially, on which guide pads are attached, the bottom surfaces of the mounting seats are flat, and when viewed from the tip in the direction of the central axis of rotation, the bottom surfaces of at least two of the mounting seats are inclined with respect to the second reference line, when a line passing through a midpoint of the bottom surface of the mounting seat and the central axis of rotation is defined as a first reference line, and a line passing through the midpoint and perpendicular to the first reference line is defined as a second reference line, the inclination directions around the midpoint with respect to the second reference line are opposite to each other, and the bottom surface of at least one of the mounting seats may not be inclined with respect to the second reference line.

[0020] The mounting seat of the body may have a diameter determining guide mounting seat arranged on the opposite side of the rotation center axis from the attachment point of the cutting insert on the body, a diameter determining guide mounting seat arranged on the opposite side of the insert across the rotation center axis, a bearing guide mounting seat arranged forward in the rotational direction from the diameter determining guide mounting seat, and an auxiliary guide mounting seat arranged rearward in the rotational direction from the diameter determining guide mounting seat.

[0021] The bearing guide mounting seat and the auxiliary guide mounting seat may be disposed on opposite sides of the central axis of rotation, shifted forward or backward from each other in the direction of rotation.

[0022] The bottom surface of the mounting seat may be inclined with respect to the central axis of rotation so as to move away from the central axis of rotation toward the tip. Effect of the Invention

[0023] According to the present invention, there are provided a guide pad that can be used over a long period of time, a body to which the guide pad is attached, and a hole drilling tool having a body on which the guide pad is provided. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a perspective view showing the overall configuration of a hole drilling tool according to this embodiment. [Diagram 2] FIG. 2 is a front view of the hole drilling tool according to this embodiment. [Diagram 3] FIG. 3 is a side view of the tip of the hole drilling tool according to this embodiment. [Figure 4] FIG. 4 is a perspective view of a mounting location of a guide pad as viewed from the recess side of the body of the hole drilling tool according to this embodiment. [Diagram 5] FIG. 5 is a perspective view of a mounting location of a guide pad as viewed from the opposite side to the recess of the body in the hole drilling tool according to the present embodiment. [Figure 6] FIG. 6 is a perspective view of the guide pad according to the present embodiment. [Figure 7] FIG. 7 is a plan view of the guide pad according to the present embodiment. [Figure 8] FIG. 8 is a diagram showing the configuration of one end side of the guide pad according to this embodiment. [Figure 9] FIG. 9 is a diagram showing the configuration of the other end side of the guide pad according to this embodiment. [Figure 10] FIG. 10 is a perspective view of a guide pad according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and duplicated description will be omitted.

[0026] The configuration of a hole drilling tool 10 according to this embodiment will be described. The hole drilling tool 10 is a cutting tool for forming a small diameter hole in a workpiece (not shown), and is also called a "BTA tool." As shown in Figs. 1 and 2, the hole drilling tool 10 includes a body 100, a cutting insert 200, and a guide pad 300.

[0027] 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 a part that is connected to a drill tube when the body 100 is attached to a machine tool (not shown).

[0028] For ease of explanation, the end side of the body 100 where the connection portion 120 is provided is also referred to as the "base end side" hereinafter. The side opposite the base end side is also referred to as the "tip side" hereinafter.

[0029] The body 100 is formed so as to extend linearly from the connection portion 120 toward the tip side. The body 100 is substantially cylindrical, and at its tip portion, a recess 111 is formed by cutting out a part of the side surface. A cutting insert 200, which will be described next, is attached to the inner surface of the recess 111.

[0030] The cutting insert 200 is a part 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 end of the cartridge in the longitudinal direction by a screw 270 penetrating the cutting insert 200, and the cartridge is fastened and fixed by the screw 270 at a position near the end of the tip side 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 the direction indicated by the arrow AR1 in FIG. 1 and FIG. 2. When the body 100 rotates, the cutting edge 210 cuts into the workpiece, cutting the workpiece and forming a hole in the workpiece. In the hole drilling tool 10 according to the present embodiment, the cutting insert 200 having the cutting edge 210 and the cartridge are replaceable separate parts as described above, and the tool is configured as a so-called "cartridge-type" tool. This allows a cutting insert 200 of a different shape to be used by replacing the cartridge with another shape. In addition, even if the cartridges have the same shape, when the periphery of the insert seat in the cartridge is damaged, only the cartridge can be replaced, so that the tool life of the body 100 can be extended.

[0031] The guide pad 300 is a member that contacts the inner surface of a hole in a workpiece during machining to suppress vibrations of the body 100. A hole formed in a workpiece by machining using the hole machining tool 10 is hereinafter also referred to as a "machined hole." The provision of the guide pad 300 allows machining to be performed while maintaining the straightness and roundness of the machined hole.

[0032] In the case where the cutting edge 210 is provided at only one location in the circumferential direction as in this embodiment, a force is applied to the cutting edge 210 during machining in a biased direction. Therefore, by providing the guide pad 300 at a position where the force can be received, deformation of the body 100 during machining can be suppressed, and the straightness and roundness of the machined hole can be maintained as described above.

[0033] 3 to 5, guide pad 300 is attached to the outer circumferential surface of body 100 at a position near the end of the body 100 on the tip side. Specifically, guide pad 300 is fastened and fixed by screws 370 in a state where it is fitted into recesses 114A, 114B, and 114C formed in body 100.

[0034] In this embodiment, a total of three guide pads 300 are provided on the body 100, and these are lined up in the circumferential direction. Note that the number of guide pads 300 attached to the body 100 may be different from that in this embodiment. For example, the body 100 may be provided with four or more guide pads 300.

[0035] A specific configuration of the guide pad 300 will be described. As shown in Fig. 6 and Fig. 7, the guide pad 300 is formed in a rectangular shape in a plan view. The guide pad 300 includes a contact surface 310, an exposed surface 320, and side surfaces 340 and 350.

[0036] The contact surface 310 is a surface that comes into contact with the bottom surfaces 113 (see FIGS. 3 to 5) of the recesses 114A, 114B, and 114C of the body 100. The contact surface 310 is formed as a flat surface. The exposed surface 320 is a surface on the opposite side to the contact surface 310, and is a surface that is exposed to the outer circumferential side when the guide pad 300 is attached to the body 100.

[0037] A through hole 360 ​​is provided in the center of the guide pad 300, penetrating from the exposed surface 320 to the abutment surface 310. The through hole 360 ​​is a circular hole. A central axis AX2 of the through hole 360 ​​is an axis perpendicular to the abutment surface 310. The through hole 360 ​​is a hole for inserting the previously described screw 370. The upper portion of the through hole 360 ​​on the exposed surface 320 side is enlarged in diameter compared to other portions in order to accommodate the head of the screw 370.

[0038] The exposed surface 320 of the guide pad 300 is a guide portion that comes into contact with the inner surface of the hole during machining. The exposed surface 320 that serves as the guide portion has a first guide surface 321, a third guide surface 323, and a fifth guide surface 325 at one end side in the longitudinal direction of the guide pad 300 (hereinafter simply referred to as the one end side), and has a second guide surface 322, a fourth guide surface 324, and a sixth guide surface 326 at the other end side in the longitudinal direction of the guide pad 300 (hereinafter simply referred to as the other end side). The first guide surface 321, the third guide surface 323, and the fifth guide surface 325 are arranged in parallel along the rotation direction when the hole drilling tool 100 processes the workpiece, in other words, along a direction perpendicular to the longitudinal direction of the guide pad 300 in a plan view of the guide pad 300, and similarly, the second guide surface 322, the fourth guide surface 324, and the sixth guide surface 326 are arranged in parallel along the rotation direction when the hole drilling tool 100 processes the workpiece, in other words, along a direction perpendicular to the longitudinal direction of the guide pad 300 in a plan view of the guide pad 300. In this way, the exposed surface 320 has a set of the first guide surface 321, the third guide surface 323, and the fifth guide surface 325 on one end side, and a set of the second guide surface 322, the fourth guide surface 324, and the sixth guide surface 326 on the other end side, and these sets are provided in point symmetrical positions with respect to the central axis AX2 of the through hole 360 ​​as the center.

[0039] 8 and 9, the first guide surface 321, the second guide surface 322, the third guide surface 323, the fourth guide surface 324, the fifth guide surface 325, and the sixth guide surface 326 are each curved in an arc shape in a cross-sectional view. The first guide surface 321 and the second guide surface 322 are arc surfaces with the same radius of curvature Ra. The third guide surface 323 and the fourth guide surface 324 are arc surfaces with the same radius of curvature Rb. The fifth guide surface 325 and the sixth guide surface 326 are arc surfaces with the same radius of curvature Rc.

[0040] The radius of curvature Ra of the first guide surface 321 and the second guide surface 322, the radius of curvature Rb of the third guide surface 323 and the fourth guide surface 324, and the radius of curvature Rc of the fifth guide surface 325 and the sixth guide surface 326 are the same. The center position of the arc of the first guide surface 321 and the second guide surface 322, the center position of the arc of the third guide surface 323 and the fourth guide surface 324, and the center position of the arc of the fifth guide surface 325 and the sixth guide surface 326 are different positions. Note that "same" does not only include a case where they are completely the same, but also a case where the difference between the radii of curvature Ra and Rb is very small, such as (Ra-Rb) / Ra<0.01 when Ra>Rb, or a case where the difference between the radii of curvature Rb and Rc is very small, such as (Rb-Rc) / Rb<0.01 when Rb>Rc, or a case where they can be said to be substantially the same.

[0041] The lengths along the arcs of the guide surfaces 321, 322, 323, 324, 325, and 326 may be the same or different. For example, the length along the arc of the fifth guide surface 325 may be shorter than the length along the arc of the first guide surface 321 and the third guide surface 323, and the length along the arc of the sixth guide surface 326 may be shorter than the length along the arc of the second guide surface 322 and the fourth guide surface 324. In addition, the lengths of the guide surfaces 321, 322, 323, 324, 325, 326 along the arcs may be adjusted in consideration of the difference in wear amount of the guide surfaces 321, 322, 323, 324, 325, 326 depending on which recess 114A, 114B, 114C the guide pad 300 is attached to. For example, the guide pad 300 attached to the recess 114B, which is a bearing guide mounting seat located closest to the rear side (farthest forward side) in the rotation direction AR1 from the cutting insert 200, receives a larger load during processing than the other guide pads 300, so the third guide surface 323 and the fourth guide surface 324 wear the most. Therefore, the lengths of the third guide surface 323 and the fourth guide surface 324 along the arcs may be made longer than those of the other guide surfaces 321, 322, 325, 326. Furthermore, the guide pad 300 attached to the recess 114C, which is an auxiliary guide mounting seat located closest to the front side (farthest to the rear side) in the rotational direction AR1 than the cutting insert 200, receives a smaller load during machining than the other guide pads 300, and therefore the amount of wear of the fifth guide surface 325 and the sixth guide surface 326 is relatively small. Therefore, the lengths of the fifth guide surface 325 and the sixth guide surface 326 along the arc may be made shorter than those of the other guide surfaces 321, 322, 325, 326.

[0042] Both side surfaces 340 and 350 extend from contact surface 310 toward exposed surface 320 and are perpendicular to contact surface 310. In guide pad 300 having a rectangular shape in a plan view, side surface 340 is a side surface on a short side, and side surface 350 is a side surface on a long side.

[0043] The first guide surface 321 has a leading chamfer 321a, a feed chamfer 321b, a trailing chamfer 321c, and a trailing ramp 321d around it. The leading chamfer 321a and the feed chamfer 321b are flat surfaces provided as a chamfered portion between the first guide surface 321 and the side surface 340, and are inclined with respect to both the first guide surface 321 and the side surface 340. Alternatively, the leading chamfer 321a and the feed chamfer 321b may be a single flat surface. The trailing chamfer 321c is a flat surface provided as a chamfered portion on the fifth guide surface 325 side, and is inclined with respect to the first guide surface 321. The trailing ramp 321d is a flat surface provided as a chamfered portion between the first guide surface 321 and the side surface 350, and is inclined with respect to both the first guide surface 321 and the side surface 350. Trailing chamfer 321c is disposed on the front side of first guide surface 321 in the rotation direction, and trailing ramp 321d is disposed on the rear side of first guide surface 321 in the rotation direction.

[0044] The second guide surface 322 has a leading chamfer 322a, a feed chamfer 322b, a trailing chamfer 322c, and a trailing ramp 322d around its periphery. The leading chamfer 322a and the feed chamfer 322b are flat surfaces provided as a chamfered portion between the second guide surface 322 and the side surface 340, and are inclined with respect to both the second guide surface 322 and the side surface 340. Alternatively, the leading chamfer 322a and the feed chamfer 322b may be a single flat surface. The trailing chamfer 322c is a flat surface provided as a chamfered portion on the sixth guide surface 326 side, and is inclined with respect to the second guide surface 322. The trailing ramp 322d is a flat surface provided as a chamfered portion between the second guide surface 322 and the side surface 350, and is inclined with respect to both the second guide surface 322 and the side surface 350. Trailing chamfer 322c is disposed on the front side of second guide surface 322 in the rotation direction, and trailing ramp 322d is disposed on the rear side of second guide surface 322 in the rotation direction.

[0045] The third guide surface 323 has a leading chamfer 323a, a feed chamfer 323b, a trailing chamfer 323c, and a trailing ramp 323d around it. The leading chamfer 323a and the feed chamfer 323b are flat surfaces provided as a chamfered portion between the third guide surface 323 and the side surface 340, and are inclined with respect to both the third guide surface 323 and the side surface 340. Alternatively, the leading chamfer 323a and the feed chamfer 323b may be a single flat surface. The trailing chamfer 323c is a flat surface provided as a chamfered portion between the third guide surface 323 and the side surface 350, and is inclined with respect to both the third guide surface 323 and the side surface 350. The trailing ramp 323d is a flat surface provided as a chamfered portion on the fifth guide surface 325 side, and is inclined with respect to the third guide surface 323. Trailing chamfer 323c is disposed on the front side of third guide surface 323 in the rotation direction, and trailing ramp 323d is disposed on the rear side of third guide surface 321 in the rotation direction.

[0046] The fourth guide surface 324 has a leading chamfer 324a, a feed chamfer 324b, a trailing chamfer 324c, and a trailing ramp 324d around its periphery. The leading chamfer 324a and the feed chamfer 324b are flat surfaces provided as a chamfered portion between the fourth guide surface 324 and the side surface 340, and are inclined with respect to both the fourth guide surface 324 and the side surface 340. Alternatively, the leading chamfer 324a and the feed chamfer 324b may be a single flat surface. The trailing chamfer 324c is a flat surface provided as a chamfered portion between the fourth guide surface 324 and the side surface 350, and is inclined with respect to both the fourth guide surface 324 and the side surface 350. The trailing ramp 324d is a flat surface provided as a chamfered portion on the sixth guide surface 326 side, and is inclined with respect to the fourth guide surface 324. Trailing chamfer 324c is disposed on the front side of fourth guide surface 324 in the rotation direction, and trailing ramp 324d is disposed on the rear side of fourth guide surface 324 in the rotation direction.

[0047] The fifth guide surface 325 has a leading chamfer 325a, a feed chamfer 325b, a trailing chamfer 325c, and a trailing ramp 325d around its periphery. The leading chamfer 325a and the feed chamfer 325b are flat surfaces provided as chamfered portions between the fifth guide surface 325 and the side surface 340, and are inclined with respect to both the fifth guide surface 325 and the side surface 340. Alternatively, the leading chamfer 325a and the feed chamfer 325b may be a single flat surface. The trailing chamfer 325c is a flat surface provided as a chamfered portion on the third guide surface 323 side, and is an inclined surface with respect to the fifth guide surface 325. The trailing ramp 325d is a flat surface provided as a chamfered portion on the first guide surface 321 side, and is an inclined surface with respect to the fifth guide surface 325. Trailing chamfer 325c is disposed on the front side of fifth guide surface 325 in the rotation direction, and trailing ramp 325d is disposed on the rear side of fifth guide surface 325 in the rotation direction.

[0048] The sixth guide surface 326 has a leading chamfer 326a, a feed chamfer 326b, a trailing chamfer 326c, and a trailing ramp 326d around its periphery. The leading chamfer 326a and the feed chamfer 326b are flat surfaces provided as chamfered portions between the sixth guide surface 326 and the side surface 340, and are inclined with respect to both the sixth guide surface 326 and the side surface 340. Alternatively, the leading chamfer 326a and the feed chamfer 326b may be a single flat surface. The trailing chamfer 326c is a flat surface provided as a chamfered portion on the fourth guide surface 324 side, and is inclined with respect to the sixth guide surface 326. The trailing ramp 326d is a flat surface provided as a chamfered portion on the second guide surface 322 side, and is inclined with respect to the sixth guide surface 326. Trailing chamfer 326c is disposed on the front side of sixth guide surface 326 in the rotation direction, and trailing ramp 326d is disposed on the rear side of sixth guide surface 326 in the rotation direction.

[0049] In addition, in guide pad 300, trailing ramp 321d of first guide surface 321 and trailing chamfer 324c of fourth guide surface 324 are formed from the same chamfered portion, and trailing ramp 322d of second guide surface 322 and trailing chamfer 323c of third guide surface 323 are formed from the same chamfered portion.

[0050] 2 to 5, the body 100 is provided with three recesses 114A, 144B, and 114C spaced apart in the circumferential direction for holding the guide pad 300. The guide pad 300 is fastened and fixed by a screw 370 inserted into a through hole 360 ​​in a state where the guide pad 300 is fitted into the recesses 114A, 144B, and 114C of the body 100.

[0051] The recesses 114A, 144B, and 114C are mounting seats for mounting the guide pads 300. The mounting seats consisting of the recesses 114A, 144B, and 114C are such that the recess 114A is a mounting seat for a diameter determining guide, the recess 114B is a mounting seat for a bearing guide, and the recess 114C is a mounting seat for an auxiliary guide.

[0052] The recess 114A serving as the diameter determining guide mounting seat is disposed on the opposite side of the central axis of rotation AX1 to the cutting insert 200. The recess 114B serving as the bearing guide mounting seat is disposed on the front side of the recess 114A serving as the diameter determining guide mounting seat in the rotation direction AR1, and the recess 114C serving as the auxiliary guide mounting seat is disposed on the rear side of the recess 114A serving as the diameter determining guide mounting seat in the rotation direction AR1.

[0053] The recess 114B serving as the mounting seat for the bearing guide and the recess 114C serving as the mounting seat for the auxiliary guide are disposed on opposite sides of the rotation axis AX1. The recess 114B serving as the mounting seat for the bearing guide and the recess 114C serving as the mounting seat for the auxiliary guide are disposed on opposite sides of the rotation axis AX1, at positions shifted forward or backward in the rotation direction AR1. In this example, the recess 114B serving as the mounting seat for the bearing guide is disposed on the opposite side of the rotation axis AX1 from the recess 114C serving as the mounting seat for the auxiliary guide, at a position shifted forward in the rotation direction AR1. The recess 114B serving as the mounting seat for the bearing guide may be disposed on the opposite side of the rotation axis AX1 from the recess 114C serving as the mounting seat for the auxiliary guide, at a position shifted backward in the rotation direction AR1.

[0054] The recesses 114A, 114B, and 114C are open on the tip side of the body 100, and the bottom surfaces of the recesses 114A, 114B, and 114C form the bottom surface 113 of the mounting seat on which the guide pad 300 is attached. The bottom surfaces 113 of the recesses 114A, 114B, and 114C are flat surfaces, and are inclined so as to move away from the rotation center axis AX1 as they go from the base end side of the body 100 to the tip side.

[0055] The recesses 114A, 114B, and 114C have opposing surfaces 115 facing both side surfaces 350 on the long side of the guide pad 300, and an opposing surface 116 facing one side surface 340 on the short side of the guide pad 300. These opposing surfaces 115 and 116 are one of the inner wall surfaces of the recesses 114A, 114B, and 114C. The opposing surfaces 115 each face the side surface 350 of the guide pad 300, and the opposing surface 116 faces one side surface 340 of the guide pad 300.

[0056] 2, in the front end view in the direction of the rotation axis AX1, in each of the recesses 114A and 114B that are mounting seats for the guide pad 300, when a line passing through a midpoint M of the bottom surface 113 of the recesses 114A and 114B and the rotation axis AX1 is defined as a first reference line L1, and a line passing through the midpoint M and perpendicular to the first reference line L1 is defined as a second reference line L2, the bottom surfaces 113 of the recesses 114A and 114B are inclined with respect to the second reference line L2, and the inclination directions around the midpoint M with respect to the second reference line L2 are opposite to each other. That is, the bottom surface 113 of the recess 114A is inclined counterclockwise with respect to the second reference line L2, while the bottom surface 113 of the recess 114B is inclined clockwise with respect to the second reference line L2, with respect to the midpoint M. As a result, the angle θ between the extension lines of the bottom surfaces 113 of the recesses 114A and 114B is an obtuse angle.

[0057] In addition, in the recess 114C, which is the mounting seat of the guide pad 300, when viewed from the tip end in the direction of the rotation axis AX1, a line passing through the midpoint M of the bottom surface 113 of the recess 114C and the rotation axis AX1 is defined as a first reference line L1, and a line passing through the midpoint M and perpendicular to the first reference line L1 is defined as a second reference line L2, the bottom surface 113 of the recess 114C coincides with the second reference line L2. In other words, the bottom surface 113 of the recess 114A is inclined counterclockwise about the midpoint M with respect to the second reference line L2, and the bottom surface 113 of the recess 114B is inclined clockwise about the midpoint M with respect to the second reference line L2, while the recess 114C has a bottom surface 113 that is not inclined with respect to the second reference line L2.

[0058] In recess 114A, guide pad 300 is attached with its end side having first guide surface 321, third guide surface 323, and fifth guide surface 325 facing the tip side of body 100, so that the normal to first guide surface 321 coincides with the normal to body 100, and this first guide surface 321 is positioned further outboard than third guide surface 323 and fifth guide surface 325 (the state in Figure 2).

[0059] In the guide pad 300 thus mounted in the recess 114A, the first guide surface 321 serves as a guide portion. Note that the bottom surface 113 of the recess 114A is inclined so as to move away from the rotation axis AX1 toward the tip side of the body 100, so that the guide pad 300 mounted in the recess 114A is inclined so as to move away from the rotation axis AX1 toward the tip side with respect to the body 100. Therefore, the portion of the first guide surface 321 near the leading chamfer 321a actually functions as a "guide portion."

[0060] Similarly, in recess 114A, guide pad 300 is attached with its end side having second guide surface 322, fourth guide surface 324, and sixth guide surface 326 facing the tip side of body 100, so that the normal to second guide surface 322 coincides with the normal to body 100, and second guide surface 322 is positioned further outboard than fourth guide surface 324 and sixth guide surface 326.

[0061] In the guide pad 300 thus mounted in the recess 114A, the second guide surface 322 serves as a guide portion. Note that the bottom surface 113 of the recess 114A is inclined so as to move away from the rotation axis AX1 toward the tip side of the body 100, so that the guide pad 300 mounted in the recess 114A is inclined so as to move away from the rotation axis AX1 toward the tip side with respect to the body 100. Therefore, the portion of the second guide surface 322 near the leading chamfer 322a actually functions as a "guide portion."

[0062] In recess 114B, guide pad 300 is attached with its end side having first guide surface 321, third guide surface 323, and fifth guide surface 325 facing toward the tip side of body 100, so that the normal to third guide surface 323 coincides with the normal to body 100, and this third guide surface 323 is positioned further outboard than first guide surface 321 and fifth guide surface 325 (the state in Figure 2).

[0063] In the guide pad 300 thus mounted in the recess 114B, the third guide surface 323 serves as a guide portion. Note that the bottom surface 113 of the recess 114B is inclined so as to move away from the rotation axis AX1 toward the tip side of the body 100, so that the guide pad 300 mounted in the recess 114B is inclined so as to move away from the rotation axis AX1 toward the tip side with respect to the body 100. Therefore, the portion of the third guide surface 323 near the leading chamfer 323a actually functions as a "guide portion."

[0064] Similarly, in recess 114B, guide pad 300 is attached with its end side having second guide surface 322, fourth guide surface 324, and sixth guide surface 326 facing the tip side of body 100, so that the normal of fourth guide surface 324 coincides with the normal of body 100, and this fourth guide surface 324 is positioned further outboard than the second guide surface 322 and the sixth guide surface 326.

[0065] In the guide pad 300 thus mounted in the recess 114B, the fourth guide surface 324 serves as a guide portion. Note that the bottom surface 113 of the recess 114B is inclined so as to move away from the rotation axis AX1 toward the tip side of the body 100, so that the guide pad 300 mounted in the recess 114B is inclined so as to move away from the rotation axis AX1 toward the tip side with respect to the body 100. Therefore, the portion of the fourth guide surface 324 near the leading chamfer 324a actually functions as a "guide portion."

[0066] In recess 114C, guide pad 300 is attached with its end side having first guide surface 321, third guide surface 323, and fifth guide surface 325 facing the tip side of body 100, so that the normal of fifth guide surface 325 coincides with the normal of body 100, and this fifth guide surface 325 is positioned further outboard than first guide surface 321 and third guide surface 323 (the state shown in Figure 2).

[0067] In the guide pad 300 thus mounted in the recess 114C, the fifth guide surface 325 serves as a guide portion. Note that the bottom surface 113 of the recess 114C is inclined so as to move away from the rotation axis AX1 toward the tip side of the body 100, so that the guide pad 300 mounted in the recess 114C is inclined so as to move away from the rotation axis AX1 toward the tip side with respect to the body 100. Therefore, the portion of the fifth guide surface 325 near the leading chamfer 325a actually functions as a "guide portion."

[0068] Similarly, in recess 114C, guide pad 300 is attached with its end side having second guide surface 322, fourth guide surface 324, and sixth guide surface 326 facing the tip side of body 100, so that the normal of sixth guide surface 326 coincides with the normal of body 100, and this sixth guide surface 326 is positioned further outboard than the second guide surface 322 and the fourth guide surface 324.

[0069] In the guide pad 300 thus mounted in the recess 114C, the sixth guide surface 326 serves as a guide portion. Note that the bottom surface 113 of the recess 114C is inclined so as to move away from the rotation axis AX1 toward the tip side of the body 100, so that the guide pad 300 mounted in the recess 114C is inclined so as to move away from the rotation axis AX1 toward the tip side with respect to the body 100. Therefore, the portion of the sixth guide surface 326 near the leading chamfer 326a actually functions as a "guide portion."

[0070] In this way, in the body 100 having recesses 114A, 114B, and 114C, in the recess 114A, the first guide surface 321 and the second guide surface 322 of the guide pad 300 can be used as guide portions, in the recess 114B, the third guide surface 323 and the fourth guide surface 324 of the guide pad 300 can be used as guide portions, and further, in the recess 114C, the fifth guide surface 325 and the sixth guide surface 326 of the guide pad 300 can be used as guide portions.

[0071] As described above, the bottom surfaces 113 of the recesses 114A and 114B of the body 100 to which the guide pad 300 is attached are inclined with respect to the second reference line L2 in a front end view in the direction of the rotation axis AX1, and the inclination directions around the midpoint M with respect to the second reference line L2 are inclined in opposite directions, and the guide pad 300 whose abutment surface 310 abuts on the bottom surfaces 113 of these recesses 114A and 114B is held inclined in opposite directions with respect to the second reference lines L2 of the recesses 114A and 114B. Furthermore, the bottom surface 113 of the recess 114C of the body 100 is aligned with the second reference line L2 in a front end view in the direction of the rotation axis AX1, and the guide pad 300 whose abutment surface 310 abuts on the bottom surface 113 of the recess 114C is held without inclination with respect to the second reference line L2 of the recess 114C.

[0072] Therefore, by attaching guide pads 300 to these recesses 114A, 114B, 114C, any one of the first guide surface 321, the third guide surface 323, and the fifth guide surface 325, or any one of the second guide surface 322, the fourth guide surface 324, and the sixth guide surface 326 can be arranged so as to be usable as a guide portion.

[0073] In other words, the first guide surface 321, the third guide surface 323 and the fifth guide surface 325, which are arc-shaped in cross section and have different central positions, are arranged in parallel along the rotation direction AR1 during machining on one end side of the guide pad 300 that abuts against the inner surface of the hole in the workpiece during machining, so that each time they wear out, the guide pad 300 can be reassembled to the body 100 so that the first guide surface 321, the third guide surface 323 and the fifth guide surface 325 abut against the inner surface of the hole, allowing one guide pad 300 to be used repeatedly.

[0074] In addition, on the exposed surface 320 of the guide pad 300, three sets of guide surfaces, namely, a set of first guide surface 321 and third guide surface 323, a set of second guide surface 322 and fourth guide surface 324, and a set of fifth guide surface 325 and sixth guide surface 326, which have different central positions of the arcs, are provided at point-symmetric positions. Therefore, by flipping the guide pad 320 around the central axis AX2 and reassembling it to the body 100, one guide pad 300 can be used repeatedly.

[0075] As described above, by repeatedly changing the orientation of the guide pad 300 and reattaching it to the body 100 multiple times, one guide pad 300 can be used six times, and therefore the guide pad 300 can be used for a long period of time.

[0076] Furthermore, since the body 100 has a recess 114A which serves as an attachment seat for the diameter determining guide, a recess 114B which serves as an attachment seat for the bearing guide, and a recess 114C which serves as an attachment seat for the auxiliary guide, and can be guided by guide pads 300 attached to these recesses 114A, 114B, and 114C, the stability of the tool during machining can be improved compared to when guide pads 300 are attached to only one or two recesses.

[0077] In particular, recess 114B, which serves as the mounting seat for the bearing guide, is positioned on the opposite side of rotation center axis AX1 from recess 114C, which serves as the mounting seat for the auxiliary guide, at a position shifted forward in rotation direction AR1. As a result, during machining, guide pad 300 attached to recess 114B can be used as a guide part that mainly contacts the inner surface of the machined hole, and guide pad 300 attached to recess 114C can be used as an auxiliary guide part. This makes it possible to increase stability during machining while suppressing contact with the inner surface of the machined hole more than necessary.

[0078] In the above embodiment, trailing chamfers 321c, 322c, 323c, 324c, 325c, 326c and trailing ramps 321d, 322d, 323d, 324d, 325d, 326d are provided on each guide surface 321, 322, 323, 324, 325, 326 of the guide pad 300. However, as shown in FIG. 10, the guide pad 300 does not necessarily have to have trailing chamfers 321c, 322c, 323c, 324c, 325c, 326c and trailing ramps 321d, 322d, 323d, 324d, 325d, 326d.

[0079] In addition, in the above embodiment, the first guide surface 321 and the third guide surface 323 may be configured to have mutually different radii of curvature of the circular arcs, the second guide surface 322 and the fourth guide surface 324 may be configured to have mutually different radii of curvature of the circular arcs, and further, the fifth guide surface 325 and the sixth guide surface 326 may be configured to have mutually different radii of curvature of the circular arcs.

[0080] In the above embodiment, the six guide surfaces 321, 322, 323, 324, 325, and 326 are provided only on one side (exposed surface 320) of the guide pad 300, but the six guide surfaces 321, 322, 323, 324, 325, and 326 may be provided on both sides of the guide pad 300. In this case, one of the two exposed surfaces 320 faces the outer periphery, and the exposed surface 320 on the opposite side abuts against the bottom surfaces 113 of the recesses 114A, 114B, and 114C to function as the "abutment surface 310". In this case, in order to increase the seating stability of the guide pad 300 attached to the recesses 114A, 114B, and 114C, the bottom surfaces 113 of the recesses 114A, 114B, and 114C may be shaped to include, for example, a concave surface that matches the shape of the exposed surface 320.

[0081] Also, four or more guide pads 300 may be attached to the body 100. For example, in the case of four, the bottom surface 113 of the first recess may be inclined by an angle α counterclockwise around the midpoint M with respect to the second reference line L2, the bottom surface 113 of the second recess may be inclined by an angle α clockwise around the midpoint M with respect to the second reference line L2, the bottom surface 113 of the third recess may be inclined by an angle β (β<α) counterclockwise around the midpoint M with respect to the second reference line L2, and the bottom surface 113 of the fourth recess may be inclined by an angle β (β<α) clockwise around the midpoint M with respect to the second reference line L2. And, in the case of five, the bottom surface 113 of the fifth recess may not be inclined with respect to the second reference line L2.

[0082] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Any design modifications made by a person skilled in the art to these specific examples are also included within the scope of the present disclosure as long as they have the features of the present disclosure. The elements of each of the above-mentioned specific examples and their arrangements, conditions, shapes, etc. are not limited to those exemplified and can be changed as appropriate. The combination of each of the elements of each of the above-mentioned specific examples can be changed as appropriate as long as no technical contradiction occurs. [Explanation of symbols]

[0083] 10 Hole drilling tools 100 Body 113 Bottom surface of recess (mounting seat) 114A Recess (mounting seat for diameter setting guide) 114B Recess (bearing guide mounting seat) 114C Recess (Auxiliary guide mounting seat) 300 Guide Pad 310 Contact surface 320 Exposed surface 321 First guide surface (guide surface) 322 Second guide surface (guide surface) 323 3rd guide surface (guide surface) 324 4th guide surface (guide surface) 325 5th guide surface (guide surface) 326 6th guide surface (guide surface) AX1 Rotation axis L1 1st reference line L2 Second Reference Line M midpoint Ra,Rb,Rc Radius of curvature

Claims

1. A guide pad for use in a hole drilling tool, a contact surface that contacts a bottom surface of a mounting seat of a body of the hole drilling tool, and a guide surface that is provided on an exposed surface on the opposite side to the contact surface and that contacts an inner surface of a hole during drilling, A guide pad in which the exposed surface has three or more guide surfaces formed in an arc shape when viewed in cross section, with each arc having a different center position, and the guide surfaces are arranged in parallel along the rotation direction during processing, and during processing, one of the three or more guide surfaces is configured to abut against the inner surface of the hole.

2. The guide pad according to claim 1 , wherein two sets of three or more guide surfaces having different arc center positions are provided on the exposed surface at point-symmetric positions.

3. The guide pad according to claim 1 , wherein the three or more guide surfaces having different central positions of the circular arcs have the same radius of curvature of each of the circular arcs.

4. The guide pad according to claim 1 , wherein the three or more guide surfaces having different central positions of the circular arcs have different radii of curvature of the circular arcs.

5. A body of a hole drilling tool having three or more mounting seats provided at intervals in a circumferential direction, and a guide pad attached to each of the mounting seats, The bottom surface of the mounting seat is a flat surface, A body in which, when viewed from the tip in the direction of the central axis of rotation, a line passing through a midpoint of the bottom surface of the mounting seat and the central axis of rotation is defined as a first reference line, and a line passing through the midpoint and perpendicular to the first reference line is defined as a second reference line, the bottom surfaces of at least two of the mounting seats are inclined with respect to the second reference line, and the inclination directions around the midpoint with respect to the second reference line are opposite to each other, and at least one bottom surface of the mounting seat is not inclined with respect to the second reference line.

6. The mounting seat is A diameter determining guide mounting seat arranged on the opposite side of the rotation center axis with respect to the mounting location of the cutting insert; a bearing guide mounting seat arranged forward in a rotational direction with respect to the diameter determining guide mounting seat; An auxiliary guide mounting seat arranged on the rear side in the rotational direction with respect to the diameter determining guide mounting seat; The body of claim 5 , comprising:

7. 7. The body according to claim 6, wherein the bearing guide mounting seat and the auxiliary guide mounting seat are disposed on opposite sides of the central axis of rotation, shifted forward or backward from each other in the direction of rotation.

8. The body according to any one of claims 5 to 7, wherein a bottom surface of the mounting seat is inclined with respect to the central axis of rotation so as to move away from the central axis of rotation toward a tip end thereof.

9. A hole drilling tool comprising a body having a plurality of guide pads and a mounting seat on which the guide pads are attached, The guide pad is a contact surface that contacts a bottom surface of the mounting seat of the body; a guide surface provided on an exposed surface opposite to the contact surface and contacting an inner surface of the hole during machining; The exposed surface has three or more guide surfaces, each of which is formed in an arc shape when viewed in cross section and has a different center position, arranged in parallel along the rotation direction during machining, and the hole machining tool is configured so that one of the three or more guide surfaces abuts against the inner surface of the hole during machining.

10. The hole drilling tool according to claim 9 , wherein two sets of three or more guide surfaces having different arc center positions are provided at point symmetric positions on the exposed surface of the guide pad.

11. The hole drilling tool according to claim 9 , wherein the three or more guide surfaces of the guide pad having different central positions of the circular arcs have the same radius of curvature of each of the circular arcs.

12. The hole drilling tool according to claim 9 , wherein the three guide surfaces of the guide pad having different central positions of the circular arcs have different radii of curvature of the circular arcs.

13. The body is provided with three or more mounting seats, each of which is spaced apart in a circumferential direction, on which the guide pad is attached, The bottom surface of the mounting seat is a flat surface, 13. The hole drilling tool according to any one of claims 9 to 12, wherein, when a line passing through a midpoint of the bottom surface of the mounting seat and the central axis of rotation is defined as a first reference line, and a line passing through the midpoint and perpendicular to the first reference line is defined as a second reference line, the bottom surfaces of at least two of the mounting seats, when viewed from the tip in the direction of the central axis of rotation, are inclined with respect to the second reference line, and the inclination directions around the midpoint with respect to the second reference line are opposite to each other, and the bottom surface of at least one of the mounting seats is not inclined with respect to the second reference line.

14. The mounting seat of the body is A diameter determining guide mounting seat arranged on the opposite side of the rotation center axis with respect to a mounting location of the cutting insert of the body; a diameter determining guide mounting seat arranged on the opposite side of the insert with respect to the rotation central axis; a bearing guide mounting seat arranged forward in a rotational direction with respect to the diameter determining guide mounting seat; An auxiliary guide mounting seat arranged on the rear side in the rotational direction with respect to the diameter determining guide mounting seat; The hole drilling tool according to claim 13, having

15. The hole drilling tool according to claim 14, wherein the bearing guide mounting seat and the auxiliary guide mounting seat are arranged on opposite sides of the rotation center axis, shifted forward or backward from each other in the rotation direction.

16. The hole drilling tool according to claim 13 , wherein a bottom surface of the mounting seat is inclined with respect to the central axis of rotation so as to move away from the central axis of rotation toward a tip end thereof.

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