Interchangeable head cutting tools

Abstract

By configuring a head-exchangeable cutting tool for machining a workpiece, a head is provided that can improve productivity by suppressing the complication of work procedures and the increase in work time. The cutting tool (100) is a head-exchangeable cutting tool having a shank (10) for machining a workpiece (300), and the head (20) includes a mounting portion (25) that is attached to the shank (10) and a mounting hole (22) that is attached to a generally rod-shaped cutting member (30). The central axis (22Z) of the mounting hole (22) is perpendicular to the fixing direction (X) of the head (20) to the shank (10).

Description

[Technical Field]

[0001] The present disclosure relates to a head for a head-exchangeable cutting tool and a cutting tool including the head. [Background technology]

[0002] As a cutting tool capable of performing internal machining such as drilling, grooving, and turning while rotating a workpiece (machined object) on an automatic lathe, Patent Document 1, for example, describes a cutting tool assembly having a generally rod-shaped cutting member held at the tip of the tool bit. The tool bit of this cutting tool assembly includes a generally prismatic holder body portion that is attached to an appropriate tool rest, and a holder tip portion that extends from the tip of the holder body and to which the cutting member is fixed. The holder tip portion also has a mounting hole that communicates with a slot (open groove) with a threaded hole, and the cutting member is inserted into the mounting hole and fixed to the holder tip portion with a screw. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Republic of Korea Patent Publication No. 10-2014-0011797 Summary of the Invention [Problem to be solved by the invention]

[0004] FIG. 8 is a side view schematically illustrating the conventional cutting tool assembly mounted on the tool post. As shown in the figure, in the conventional cutting tool assembly, the holder tip, to which the rod-shaped cutting member 610 is fixed, is integrally formed with the holder body to form the tool bit 600. Furthermore, the main spindle 500 or a wall that holds the workpiece is typically positioned in the direction of removal of the cutting member 610 (indicated by the arrow in the figure). For this reason, the cutting member 610 cannot be replaced inside the automatic lathe. To replace the cutting member 610, the entire tool bit 600 must be removed from the tool post 200. As a result, the procedure for replacing the cutting member 610 tends to be complicated and the work time tends to increase. Therefore, it is conceivable to design the tool so that the holder tip can be removed from the holder body, i.e., as a head-exchangeable tool. However, in the conventional cutting tool assembly described above, the tip of the holder is L-shaped to hold the cutting member 610, which makes the structure large, and it is therefore difficult to secure space to install a new mechanism or structure for replacing the tip of the holder.

[0005] Therefore, the present disclosure has been made in consideration of the above circumstances, and aims to provide a head that can improve productivity by configuring a head-exchangeable cutting tool for processing a workpiece, thereby suppressing the complication of work procedures and the increase in work time, and a cutting tool equipped with the head. [Means for solving the problem]

[0006] [1] One example of a head according to the present disclosure is a head for an exchangeable-head cutting tool having a shank and used to machine a workpiece. The head includes a mounting portion attached to the shank and a mounting hole into which a generally rod-shaped cutting member is attached. The central axis of the mounting hole is configured to be perpendicular to the direction in which the head is fixed to the shank. In this case, the above-described configuration of the mounting hole allows the head structure to be simplified and made smaller than conventional heads. This allows for the realization of an exchangeable-head cutting tool useful for machining the wall diameter of a workpiece using a generally rod-shaped cutting member. Furthermore, because the head structure is simplified and made smaller, interference with the workpiece and interference with other cutting tools when used adjacent to them can be reduced.

[0007] [2] In the above configuration, a fixing screw hole may be provided that is drilled from the side of the mounting hole so as to communicate with the mounting hole, and into which a screw for fixing the cutting member to the head is threaded. This allows the screw for fixing the cutting member to be housed inside the head, which contributes to a smaller head. Furthermore, the screw can be easily seen from the side of the head, making it easier to attach the cutting member to the head.

[0008] [3] In this case, more specifically, the interior angle α formed by the central axis of the fixing screw hole and a plane perpendicular to the fixing direction of the shank and head may satisfy the relationship expressed by 0°<α≦90° (Equation (1)). If the interior angle α is set within this range, the effective length of the screw for fixing the cutting member to the head can be secured, and the screw tightening operation can be easily performed.

[0009] [4] Furthermore, in the above configuration, a flow path (hole, groove, etc.) may be provided near the mounting hole to discharge cutting oil toward the cutting member attached to the mounting hole. In this case, it is possible to secure installation locations for multiple cutting oil flow paths in positions close to the cutting member, making it easier to increase the amount of cutting oil supplied.

[0010] [5] In this case, more specifically, the flow passages may be configured to be cut out in the edge of the opening of the mounting hole, which makes it easier to form multiple cutting oil flow passages at positions closer to the cutting member.

[0011] [6] The head, excluding the mounting portion, may be substantially rectangular. This allows the entire head to be configured in a shape with a desired aspect ratio, making it easier to make the head thinner so as to avoid interference with adjacent cutting tools when it is fixed to a shank and mounted on a tool rest.

[0012] [7] Furthermore, when the head with the cutting member attached is fixed to the shank, the cutting edge of the cutting member may be configured to be positioned closer to the head than the end face of the shank, thereby simplifying and miniaturizing the overall shape of the cutting member when configured.

[0013] [8] Alternatively, the central axis of the mounting hole may be positioned within the lateral width of the shank, which further simplifies and downsizes the head structure and further reduces interference with the workpiece and other cutting tools when used adjacent to them.

[0014] [9] An example of a cutting tool according to the present disclosure can be effectively configured with a head according to the present disclosure. That is, the example of the cutting tool is a head-exchangeable cutting tool having a shank and configured to machine a workpiece, the head having a mounting portion attached to the shank and a mounting hole into which a generally rod-shaped cutting member is attached, and the central axis of the mounting hole is perpendicular to the direction in which the head is fixed to the shank. [Effects of the Invention]

[0015] According to the present disclosure, a head-exchangeable cutting tool for processing a workpiece can be effectively configured, thereby making it possible to suppress the complication of work procedures and the increase in work time, thereby improving productivity. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective view showing an example of a state in which a cutting tool according to an embodiment of the present disclosure is attached to a tool rest of an automatic lathe. FIG. [Figure 2] FIG. 2 is a perspective view schematically illustrating an example of a shank included in a cutting tool according to an embodiment of the present disclosure. [Figure 3] 1A is a bottom view showing an example of a head provided in a cutting tool according to an embodiment of the present disclosure, and FIG. 1B is a right side view of the same. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3(B) as viewed from the front. [Figure 5] (A) to (C) are bottom views (perspective views) showing an example of a head having second mounting holes arranged so that α=0°, α=30°, and α=45°, respectively. [Figure 6] (A) is a bottom view showing an example of a head, similar to Figure 5, and (B) is a perspective view showing a schematic view of the state when cutting oil is released from the head with a cutting member attached to the head shown in (A). [Figure 7] FIG. 1 is a right side view illustrating an example of a cutting tool according to an embodiment of the present disclosure. [Figure 8] FIG. 10 is a side view schematically showing a conventional cutting tool assembly installed on a tool rest. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in each drawing will be assigned the same reference numerals whenever possible, and redundant description will be omitted. Note that the following embodiments are examples for explaining the present disclosure, and are not intended to limit the present disclosure to only these embodiments. Furthermore, the present disclosure can be modified in various ways without departing from the gist thereof. Furthermore, a person skilled in the art can adopt embodiments in which the elements described below are replaced with equivalents, and such embodiments are also within the scope of the present disclosure.

[0018] FIG. 1 is a perspective view showing an example of a state in which a cutting tool according to this embodiment is attached to a tool rest of an automatic lathe. For convenience in describing the relative directional relationships, the downward direction in the coordinate axes shown in FIG. 1 may be referred to as the forward direction X1 and the upward direction as the backward direction X2, and both directions may be collectively referred to as the forward-backward direction X. Furthermore, in the coordinate axes shown in FIG. 1, the diagonally downward right direction may be referred to as the rightward direction Y1 and the diagonally upward left direction may be referred to as the backward direction Y2, and both directions may be collectively referred to as the forward-backward direction Y. Furthermore, in the coordinate axes shown in FIG. 1, the diagonally downward left direction may be referred to as the upward direction Z1 and the diagonally upward right direction may be referred to as the downward direction Z2, and both directions may be collectively referred to as the vertical direction Z. In addition, a top view (bottom view) refers to the viewpoint when the head 20 and cutting tool 100 are viewed from above Z1 toward below Z2 (from below Z2 toward above Z1), a front view (rear view) refers to the viewpoint when the head 20 and cutting tool 100 are viewed from the front X1 toward the rear X2 (from rear X2 toward the front X1), and a right side view (left side view) refers to the viewpoint when the head 20 and cutting tool 100 are viewed from the right Y1 toward the left Y2 (from left Y2 toward right Y1).

[0019] 1, cutting tool 100 according to an embodiment of the present disclosure and other cutting tools 400 are applied to an automatic lathe (not shown) that automatically performs lathe work, and a tool bit is fixed to tool rest 200 having multiple gang-shaped pedestals K. The tool rest 200 is moved in the front-to-back direction X, the left-to-right direction Y, and the up-to-down direction Z depending on the turning mode of workpiece 300 (for example, it is usually operated within the XZ plane, and optionally moved in the Y-axis direction as well), and cutting tools 100, 400 can be appropriately selected and replaced to perform the desired wall diameter machining. Note that in an automatic lathe, workpiece 300 may be turned by moving cutting tool 100 along an appropriate machining direction while feeding out workpiece 300 in a predetermined direction, thereby machining workpiece 300 to carve out a three-dimensional shape.

[0020] Furthermore, the cutting tool 100 of this embodiment used for such turning is a head-exchangeable cutting tool in which the head 20 can be attached and detached to the shank 10 of the cutting tool. As shown in Fig. 1, a protrusion 11 is provided on the front of the shank 10, and a recess 21 is formed on the top surface of the head 20, and these protrusion 11 and recess 21 fit together to position the shank 10 and the head 20. As will be described later, the protrusion 25 of the head 20 is attached to the mounting hole 12 of the shank 10, thereby fixing the two together.

[0021] FIG. 2 is a perspective view schematically illustrating an example of a shank 10 provided in the cutting tool 100. Note that the protrusion 11 shown in FIG. 1 is omitted from the shank 10 illustrated in FIG. 2. As illustrated in FIG. 2, the shank 10 is formed integrally with a main body portion 10H arranged on the rear X2 side and a step portion 10S arranged on the front X1 side. Of these, the main body portion 10H is a portion (a portion having a constant vertical width 10Zw) that is installed so as to be gripped between the bases K, K of the tool rest 200. The step portion 10S is a portion that protrudes in a step shape (in other words, a hook shape, a hook-like shape, or an L-shape) so as to bend upward Z1 from the lower part of the main body portion 10H.

[0022] As mentioned above, the front surface 10F of this step portion 10S is provided with a convex portion 11 (not shown), and also has a mounting hole 12 into which a convex portion 25 of the head 20 (described later) is inserted. Furthermore, a fixing screw hole 13 is drilled in the top surface 10J of the step portion 10S, which communicates with the mounting hole 12 and into which a screw 13N is fitted for fixing the head 20 to the shank 10. When the screw 13N is threaded and tightened into the fixing screw hole 13, it comes into contact with the convex portion 25 and presses the head 20, thereby fixing the head 20 to the shank 10 as shown in FIG.

[0023] 3A is a bottom view showing an example of the head 20 provided in the cutting tool 100, and FIG. 3B is a right side view thereof. Furthermore, FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3B as viewed from the front. As shown in these figures, the head 20 has a generally rectangular parallelepiped shape with a downwardly projecting portion 20S. As described above, a recess 21 that fits with the projecting portion 11 of the shank 10 is provided on the rear surface 20U of the head 20 near the upper Z1 side. A projecting portion 25 (an example of a "mounting portion" in the present disclosure) that fits into the mounting hole 12 of the shank 10 protrudes toward the rear X2 on the rear surface 21U slightly toward the lower Z2 side (near the downwardly projecting portion 20S). Furthermore, a recess 25J is formed on the upper surface of the projecting portion 25, against which a screw 13N tightened in the fixing screw hole 13 of the shank 10 abuts. Further, a mounting hole 22 (corresponding to an example of the "mounting hole" in the present disclosure) is drilled in the bottom surface 21F of the head 20, into which the generally rod-shaped cutting member 30 is attached.

[0024] The central axis 22Z of the mounting hole 22 is perpendicular to the fixing direction of the head 20 to the shank 10 (the fixing direction between the shank 10 and the head 20 when viewed from the head 20 side, and the direction in which the central axis 20X of the protrusion 25 extends (the front-to-back direction X)). When viewed from the shank 10 side, this "fixing direction" coincides with the longitudinal direction in which the shank 10 extends in this embodiment, and also coincides with the direction in which the head 20 faces the workpiece 300, as shown in FIG. 3(B). In other words, the mounting hole 22 is configured so that its central axis 22Z is ​​perpendicular to the longitudinal direction in which the central axis 20X of the protrusion 25 of the head 20 extends (the front-to-back direction X), and is disposed within the short-side width 10Yw of the shank 10 (see FIG. 1B).

[0025] Furthermore, a plurality of fixing screw holes 24, 24 (corresponding to an example of "fixing screw holes" in the present disclosure) are drilled in the right side surface 20R of the head 20. The fixing screw holes 24, 24 communicate with the mounting hole 22 and receive screws 24N for fixing the cutting member 30 to the head 20. When the screws 24N are threadedly engaged with the fixing screw holes 24 and tightened, the screws 24N come into contact with and press against the cutting member shank portion 31 of the cutting member 30, and the cutting member 30 is fixed to the head 20 as shown in Figures 1A, 1B, and 3(B). Furthermore, the fixing screw hole portions 24, 24 are configured so that the interior angle α formed between their central axis 24A and the plane 20P (front-to-back direction Z or left-to-right direction Y) perpendicular to the fixing direction of the head 20 to the shank 10 described above, i.e., the direction in which the central axis 20X of the convex portion 25 of the head 20 extends (front-to-back direction X), preferably satisfies the relationship expressed by the following formula (1), more preferably the following formula (2), and even more preferably the following formula (3). 0°<α≦90° …(1) 0°<α≦60° …(2) 30°≦α≦60° …(3)

[0026] 5A to 5C are bottom views (perspective views) showing an example of the head 20 having the fixing screw holes 24 provided so that α=0°, α=30°, and α=45°, respectively. Note that in these figures, the protrusions 25 are not shown.

[0027] 6(A) is a bottom view of an example of the head 20, similar to FIG. 5, and FIG. 6(B) is a perspective view schematically illustrating the state when cutting oil is released from the head 20 with a cutting member 30 attached to the head shown in FIG. 6(A). As shown in these figures and FIGS. 3 and 4, a group of oil holes 23 is drilled near the mounting hole 22 in the head 20 for releasing cutting oil CO (see FIG. 6(B)) toward the cutting member 30 attached to the mounting hole 22. The group of oil holes 23 corresponds to the outlet or supply port of a supply flow path (not shown) for cutting oil CO provided in the shank 10 and the head 20. The cutting oil CO supplied through the head 20 is distributed to each oil hole (corresponding to an example of a "flow path" in this disclosure) of the group of oil holes 23 and released toward the cutting edge 32 of the cutting member 30 and its surroundings.

[0028] More specifically, each oil hole in the oil hole group 23 has an opening that is cut outward from the edge of the opening of the mounting hole 22 in a shape of a small arc. Among them, oil holes 23X1 and 23X2, from which cutting oils COX1 and COX2 (see FIG. 6(B)) are respectively disposed facing each other at the front X1 and rear X2 of the opening of the mounting hole 22. Furthermore, oil holes 23Y1 and 23Y2, from which cutting oils COY1 and COY2 (see FIG. 6(B)) are respectively disposed facing each other at the right Y1 and left Y2 of the opening of the mounting hole 22. Cutting oil CO30 shown in FIG. 6(B) is discharged from an oil hole 31X drilled from the inside of the main body 31 of the cutting member 30 so as to open obliquely upward toward X1 on the outer wall.

[0029] In the head 20 configured as described above and the cutting tool 100 including the same, the central axis 22Z of the mounting hole 22 in the head 20 extends in the up-down direction Z of the head 20. That is, the central axis 22Z is ​​perpendicular to the front-rear direction X, which is the direction in which the head 20 is fixed to the shank 10, and extends in the direction in which the head 20 faces the workpiece 300. Moreover, the central axis 22Z is ​​configured to be disposed within the lateral width 10Yw of the shank 10. Therefore, the structure of the head 20 can be simplified and made smaller (more compact) than conventional heads. As a result, when performing wall diameter machining of the workpiece 300 using the generally rod-shaped cutting member 30, the cutting tool 100 can be configured as a head-exchangeable cutting tool, as in this embodiment. Therefore, when replacing the cutting member 30 or changing its mounting position to match the shape and cutting form of the workpiece 300, the cutting member 30 can be replaced inside the automatic lathe. This prevents the replacement procedure from becoming complicated and the work time from increasing, thereby improving productivity.

[0030] Furthermore, because the structure of the head 20 can be simplified and made smaller in size, it is possible to reduce interference between the head 20, and therefore the cutting tool 100, and the workpiece 300, as well as interference when the cutting tool 100 is used in conjunction with another cutting tool 400 adjacent to it. As a result, many cutting tools 100, 400 can be mounted on the tool rest 200 to machine the workpiece 300, thereby reducing the time required to change cutting tools and further increasing productivity.

[0031] Furthermore, a fixing screw hole 24 that communicates with the mounting hole 22 is provided on the right side surface 20R of the head 20, and a screw 24N for fixing the cutting member 30 to the head 20 is configured to be fitted into the fixing screw hole 24, so that the screw 24N can be housed inside the head 20. This does not hinder the head 20 from being made smaller, and also has the advantage that the cutting member 30 can be easily attached to the head 20 because the screw 24N can be easily confirmed from the side of the head 20.

[0032] Furthermore, the interior angle α formed by the central axis 24A of the mounting hole portion 24 and a plane 20P (front-back direction X or left-right direction Y) perpendicular to the fixing direction (up-down direction X) of the shank 10 and the head 20 is preferably configured to satisfy the relationship expressed by the following formula (1), more preferably the following formula (2), and even more preferably the following formula (3). 0°≦α≦60° …(1) 0°≦α≦45° …(2) 30°≦α≦45° …(3) This has the advantage that the effective length of the screw 24N for fixing the cutting member 30 to the head 20 is ensured, while the tightening operation of the screw 24N is made easier.

[0033] Furthermore, a plurality of oil holes 23X1, 23X2, 23Y1, 23Y2 that respectively discharge cutting oils COX1, COX2, COY1, COY2 toward the cutting member 30 are arranged near the mounting hole 22, more specifically, as small arc-shaped notches on the opening edge of the mounting hole 22. This allows a large amount of cutting oil CO to be supplied toward the cutting member 30 from a position close to the cutting member 30, thereby improving the cooling performance of the cutting member 30 and enabling further improvements in productivity and durability.

[0034] The above description of the present embodiment is provided to facilitate understanding of the present disclosure and is not intended to limit or construe the present disclosure. In other words, the present disclosure is not necessarily limited to the specific configurations described above. Design modifications made by a person skilled in the art to these specific configurations are also encompassed within the scope of the present disclosure as long as they comprise the features of the present disclosure. Furthermore, unless otherwise specified, the elements, arrangements, materials, conditions, shapes, dimensions, sizes, scales, etc. of the specific configurations described above are not limited to those exemplified and can be modified as appropriate. Furthermore, the elements of the specific configurations described above can be used in various combinations as appropriate, as long as no technical contradictions arise.

[0035] That is, for example, the mounting hole portion 24 may be a single one, or three or more may be provided. The head 20 does not need to be provided with a forward protrusion 20S that protrudes forward. Furthermore, the screws 13N and 24N do not need to be of the insert type. Additionally, the mounting hole portion 24 may be provided on the left side surface 20L instead of, or in addition to, the right side surface 20R of the head 20. Furthermore, the head 20 may be fastened and fixed to the shank 10 simply by attaching the protrusion 25 to the mounting hole portion 12, without providing the protrusion 11 of the shank 10 and the recess 21 of the head 20. Additionally, the oil hole group 23 may be a groove instead of a hole, for example, when provided in the head 20 alone. Furthermore, as shown in Figure 7, when a head 20 equipped with a cutting member 40 having a cutting member shank portion 41 and a cutting edge 42 is fixed to the shank 10, it is preferable that the cutting edge 42 be positioned closer to the head 20 than the vertical position Z10 of the end face 10T (bottom surface or lower surface) of the shank, as this makes the head 20 more compact. [Explanation of symbols]

[0036] 10...shank, 10B...rear face, 10H...main body, 10S...step portion, 10F...front face, 10Yw...width in the lateral direction, 10Zw...width in the longitudinal direction, 11...convex portion, 12...mounting hole portion, 13...fixing screw hole portion, 20...head, 20L...left side face, 20P...flat face, 20R...right side face, 20S...front convex portion, 20U...top face, 20X...center axis, 21...recess (mounting portion), 21F...front face, 21U...top face, 22...mounting hole portion (first mounting hole portion), 22Z...center axis, 23...oil hole group, 23X1, 23X2, 23Y1, 23Y2...oil holes , 24...Mounting hole portion (second mounting hole portion), 24A...Center axis, 25...Convex portion (mounting portion), 25B...Concave portion, 30, 40...Cutting member, 31, 41...Cutting member shank portion, 31X...Oil hole, 32, 42...Cutting edge, 100...Cutting tool, 200...Tool rest, 300...Workpiece, 400...Other cutting tools, CO30, COX1, COX2, COY1, COY2...Cutting oil, K...Base, X...Up-down direction, X1...Up, X2...Down, Y...Left-right direction, Y1...Right, Y2...Left, Z...Front-rear direction, Z1...Forward, Z2...Backward, α...Interior angle

Claims

1. A head-exchangeable cutting tool including a shank and a head having a longitudinal direction, The head has a mounting portion that is mounted on the shank, and a mounting hole portion into which a cutting member that has a substantially cylindrical and rod-like shape is mounted, a central axis of the mounting hole portion is perpendicular to a direction in which the head is fixed to the shank, The end surface of the head to which the cutting member is attached and the cutting edge of the cutting member are disposed on the side where the cutting edge is provided and closer to the head than the position of the end surface of the shank along the longitudinal direction. Cutting tool with replaceable head.

2. 2. The cutting tool according to claim 1, wherein the head has a fixing screw hole portion that is drilled from a side of the mounting hole portion so as to communicate with the mounting hole portion and into which a screw for fixing the cutting member to the head is threaded.

3. the fixing screw hole is located closer to the mounting portion than the central axis of the mounting hole, The interior angle α between the central axis of the fixing screw hole portion and a plane perpendicular to the fixing direction of the shank and the head is expressed by the following formula (1): ０°＜α≦９０° …（１）、 satisfy the relationship expressed by 3. The head-exchangeable cutting tool according to claim 2.

4. The cutting tool according to claim 2 , wherein the screw is housed inside the head.

5. The cutting tool according to claim 1 , wherein the head is provided in the vicinity of the mounting hole and includes a flow path through which cutting oil is discharged toward the cutting member attached to the mounting hole.

6. The cutting tool according to claim 5 , wherein the flow passage is formed so as to change direction inside the head.

7. The cutting tool according to claim 5 , wherein the flow passage is formed as a notch on an edge of an opening of the mounting hole.

8. The cutting tool according to claim 7 , wherein the head has a plurality of the notched flow passages.

9. A head-exchangeable cutting tool as described in claim 1, wherein the portion of the head excluding the mounting portion is approximately rectangular.

10. 10. The cutting tool according to claim 9, wherein a central axis of the mounting portion is located closer to the end face where the mounting hole portion is drilled than a center of the substantially rectangular parallelepiped portion in the direction of the central axis of the mounting hole portion.

11. The cutting tool according to claim 1 , wherein a central axis of the mounting hole in the head is located within a lateral width of the shank.

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