JP2006247790A - Throw-away cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throw-away cutting tool, quickly performing the removal/attaching work for a throw-away tip and preventing breakage of the throw-away tip and deformation of a tip seat of a tool body in a corner change of the throw-away tip. <P>SOLUTION: This throw-away cutting tool removably screws the throw-away tip 100 on a tip seat 200 of the tool body by a clamp screw 10. The outer peripheral part of a male screw part 12 of the clamp screw 10 is provided with cutout parts 12a extended along the direction of the axis CL1 of the clamp screw 10 and opened to the tip face 12c of the male screw part 12, which are formed in one place in the circumferential direction or two or more places at spaced from each other in the circumferential direction, and also a cutout part 22a corresponding to a non-cutout part 12b of the male screw part 12 is formed in the inner peripheral part of the female screw part 22 of the female screw hole 20 so that the male screw part 12 can be inserted in the female screw part 22 by a predetermined length. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a throw-away cutting tool in which a throw-away tip is screwed to a tip seat provided in a tool body.

This type of throw-away cutting tool is illustrated in FIGS. In the throw-away tool shown in FIG. 12, the attachment of the throw-away tip (2) to the tool body (1) engages with a mounting hole penetrating the upper and lower surfaces (8, 9) of the throw-away tip (2). This is done by screwing the clamp screw (3) into a female screw hole (7) provided in the bottom surface (4) of the chip seat (see, for example, Patent Document 1).

In the above throw-away tool, when the clamp screw (3) is removed from the tool body (1) in order to replace the throw-away tip (2) or change the corner, the male screw portion of the clamp screw (3) is inserted into the female screw hole. Since the clamp screw (3) has to be rotated and removed many times over the length to be screwed into the female screw part of (7), it took a very long time. Further, when the throw-away tip (2) is mounted on the tip seat, the throw-away tip (2) is supported with one hand or pressed against the tip seat, so that the clamping work of the clamp screw (3) is a one-handed work. In addition, a general cutting tool uses a relatively small size screw of M2 to M5, so workability is very poor.

The throw-away type face mill shown in FIG. 13 is intended to shorten the time required for the corner change of the throw-away tip, and the wall surface (17A) of the tip pocket (17) facing the outer peripheral side of the tool body (11). A recess (19) that is recessed toward the inner peripheral side of the tool body (11) is formed at a position that is located immediately in the rotational direction (T) of the tip seat (18), and the recess (19) When the throw-away tip (20) is rotated around the axis (C) of the clamp screw (25), the corner portion (23) of the throw-away tip (20) can pass therethrough. Is a cutting tool characterized by With such a configuration, the clamp screw (25) is loosened to such an extent that the throw-away tip (20) can be moved to the vicinity of the recess (19), and the throw-away tip (20) is clamped to the vicinity of the recess (19). After moving along the screw (25) and then rotating around the axis (C) of the clamp screw (25), the corner (23) of the throw-away tip (20) moves inside the recess (19). Since it can pass through, the corner change can be performed without completely removing the clamp screw (25) from the tool body (11). Therefore, it is possible to shorten the time taken for the corner change of the throw-away tip (20) (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 51-145072 JP 2002-326114 A

However, in the throw-away face mill shown in FIG. 13, the corner change time of the throw-away tip (20) can be shortened, but when replacing the throw-away tip (20), the clamp screw (25) is attached to the tool body. Since it has to be completely extracted from (11), the time required for this work could not be shortened. In the corner change of the throw-away tip (20), the throw-away tip (20) is moved to the vicinity of the recess (19) located immediately in front of the rotation direction (T) of the tip seat (18). Since the throw-away tip (20) and the tip seat (18) are close to each other, it is difficult to completely remove chips, dust, cutting oil, and the like attached to each. Therefore, when the throw-away tip (20) is mounted on the tip seat (18) again, the above chips, dust, cutting oil, etc. are sandwiched between the throw-away tip (20) and the tip seat (18). As a result, the throw-away tip (20) may be damaged or the tip seat (18) may be deformed. Further, the recess (19) recessed to the inner peripheral side of the tool body (11) formed to pass the corner portion (23) of the throw-away tip (20) invites a decrease in strength of the tool body (11). There was a risk of it.

The present invention has been made in view of the above circumstances, and an object of the present invention is to enable quick attachment / detachment of the throw-away tip and to change the throw-away tip at the corner change. An object of the present invention is to provide a throw-away type cutting tool that prevents breakage and deformation of a tip seat of a tool body.

In order to solve the above-described problems, the throw-away cutting tool of the present invention is configured so that the lower surface of the throw-away tip is seated on the bottom surface of the tip seat provided in the tool body, and the mounting hole penetrates the upper and lower surfaces of the throw-away tip. In a throw-away type cutting tool in which the throw-away tip is detachably attached to the tool body by screwing the clamp screw inserted into the female screw hole provided in the bottom surface of the tip seat, the male screw portion of the clamp screw In the outer peripheral portion, a notch portion extending along the axial direction of the clamp screw is formed at one location in the circumferential direction or at two or more intervals and opened at the front end surface of the male screw portion, and The inner threaded part of the female threaded hole has an axial direction of the female threaded hole at a circumferential position corresponding to the non-notched part that is the remaining part excluding the notched part of the male threaded part. A notch portion extending along the opening of the female screw portion and opening at the mouth of the female screw portion is formed, and the forming range in the circumferential direction of each cutout portion formed in the male screw portion and the female screw portion is set to a counterpart side corresponding to the notch portion. A throw-away cutting tool characterized in that it is larger than the formation range in the circumferential direction of the non-notched portion of the threaded portion.

In the above throw-away type cutting tool, when the throw-away tip is screwed to the tip seat at least one of the notch portions formed in the male screw portion of the clamp screw and the female screw portion of the female screw hole It is preferable that the male threaded portion is shorter than the length (L) into which the male threaded portion is screwed into the female threaded portion, and the axial lengths (L1, L2) of the respective notch portions are set to the throwaway tip. It is more preferable that the length of the male screw portion is 30% to 70% of the length (L) that the male screw portion is screwed into the female screw portion when screwed into the chip seat. Furthermore, it is particularly preferable that the lengths (L1, L2) in the axial direction of the respective notches are substantially equal.

In the above throw-away type cutting tool, it is preferable to include a biasing means for biasing the clamp screw upward from the bottom of the female screw hole.

The above throw-away cutting tool is preferably any one of a throw-away turning tool, a throw-away turning tool, and a throw-away drilling tool.

According to the throw-away type cutting tool of the present invention, when the clamp screw is screwed into the female screw hole in order to attach the throw-away tip to the chip seat, the axial centers of both the clamp screw and the female screw hole are substantially matched, and By aligning the notch formed in the male screw portion of the clamp screw with the non-notched portion formed in the female screw portion of the female screw hole in the circumferential direction, the clamp screw is moved from the mouth of the female screw hole to the notch portion. It can be inserted into the female screw hole without being screwed (rotated) over the axial length, and then rotated until the throw-away tip is screwed and screwed into the female screw hole. Therefore, since it is not necessary to screw the clamp screw over the length of screwing from the mouth of the female screw hole as in the conventional cutting tool, the time required for screwing the clamp screw is shortened. Attaching the throw-away tip to the tip seat accompanying the replacement can be performed quickly. The time required for the work of removing the clamp screw from the female screw hole, which is the reverse of this procedure, is shortened, and the work of removing the throw-away tip can be performed quickly.

In addition, when the corner of the throw-away tip is changed, the clamp screw is completely removed from the tool body, so that chips, dust, cutting oil and the like attached to the throw-away tip and the tip seat are completely removed. Therefore, when the throw-away tip is mounted on the tip seat again, the above-mentioned chips, dust, cutting oil, etc. are not caught between the throw-away tip and the tip seat. Deformation of the tip seat of the tool body can be prevented.

In addition, like the cutting tool disclosed in Patent Document 2, there is a recess recessed on the inner peripheral side of the tool body for allowing the corner portion of the throw-away tip to pass through at a location located immediately forward in the rotational direction of the tip seat. Since it is unnecessary, the strength of the tool body does not decrease.

When viewed from the axial direction of the clamp screw and the female screw hole, the notch portion formed in the male screw portion of the clamp screw and the female screw portion of the female screw hole is more circumferential than the non-notched portion of the mating screw portion corresponding to the notch portion. Since the formation range is slightly enlarged, the insertion / removal operation of the clamp screw into the female screw hole can be performed easily and quickly. If the circumferential formation range of the notch portion is excessive, the circumferential formation range of the non-notch portion that is the remaining portion excluding the notch portion is narrowed, and the axial force of the clamp screw is excessively reduced, or Since there is a possibility that a high load is applied to the non-notched portion and damage is likely to occur, the circumferential formation range of the notched portion is the circumferential direction of the non-notched portion provided in the mating screw portion corresponding to the notched portion. It is preferable to set it in the range of more than 100% and 150% or less of the formation range. Alternatively, when the range cut out by one cutout portion on the circumference of the effective diameter of the male screw portion and the female screw portion is represented by a central angle (θ1, θ3), the central angle (θ1, θ3) is 20 °. It is preferably set in the range of ˜315 °, and when two or more notches are formed, the sum of the central angles (θ1, θ3) is formed in the range of 40 ° to 315 °. Is preferred.

In the male screw portion of the clamp screw and the female screw portion of the female screw hole, at least one of the cutout portions formed in each of the male screw portion is screwed into the female screw portion when the throwaway tip is screwed to the chip seat. Since the length is shorter than the length (L), a part of the non-cutout portion formed in at least one of the male screw portion and the female screw portion is formed in the mating screw portion. In addition, since it is screwed into the entire circumferential screw portion, both the clamp screw and the female screw hole are securely screwed and will not come off.

The lengths (L1, L2) in the axial center (CL1, CL2) direction of the respective notches formed in the male screw portion of the clamp screw and the female screw portion of the female screw hole are as described above when the throwaway tip is screwed to the tip seat. When the male screw portion is less than 30% of the length (L) into which the female screw portion is screwed, it is difficult to obtain the desired effect of shortening the time required for screwing and extracting the clamp screw. Since the load on each non-notched part formed in the male thread part and the female thread part becomes high, the non-notched part may be deformed or damaged. The lengths (L1, L2) of the respective notches may be different from each other as long as they are within the above range. In this case, the length that can be inserted into and removed from the female screw hole without rotating the clamp screw is as follows. The length of each cutout portion (L1, L2) is the shorter one.

When the axial lengths (L1, L2) of the notches formed in the male screw portion of the clamp screw and the female screw portion of the female screw hole are substantially equal, the clamp screw inserted into the female screw hole is screwed. The non-notched portions formed on the male screw portion and the female screw portion are immediately screwed with the other circumferential screw portion, so that the clamp screw and the female screw hole are strongly screwed together, and the throw away A reduction in the force for fixing the tip can be avoided, and damage to the non-notched portion can be prevented.

In the case where an urging means for urging the clamp screw from the bottom of the female screw hole toward the mouth is provided, immediately after the screwed state between the male screw portion of the clamp screw and the female screw portion of the female screw hole is released, Since the clamp screw is pushed up in the direction of extracting from the female screw hole, the extraction operation of the clamp screw can be performed more easily and quickly.

Embodiments to which the present invention is applied will be described below with reference to the drawings. FIG. 1 is a view for explaining a clamp screw to which the present invention is applied, in which (a) is a plan view, (b) is a front view, (c) is a side view, and (d) is a bottom view. FIG. 2 is a view for explaining a female screw hole screwed into the clamp screw shown in FIG. 1, (a) is a view seen from the axial direction, (b) is a cross-sectional view along the line AA, and (c) is a cross-sectional view. It is a BB sectional view. 3 is a view showing a state in which the clamp screw shown in FIG. 1 is inserted into the female screw hole shown in FIG. 2, wherein (a) is a longitudinal sectional view and (b) is a sectional view taken along the line CC. 4 is a view showing a state in which the throw-away tip is fixed to the tip seat by the clamp screw shown in FIG. 1, wherein (a) is a longitudinal sectional view, (b) is a sectional view taken along the line DD, and (c). Is a sectional view taken along line E-E.

As illustrated in FIG. 1, the clamp screw (10) includes a head (11) on one end side in the axial center (CL1) direction, a male screw portion (12) on the other end side, and the head (11 ) And the male threaded portion (12), and a cylindrical portion (13) connected to both. A wrench hole is provided in the end surface of the head (11), and a portion of the head (11) adjacent to the cylindrical portion (13) has a truncated cone shape that gradually increases in diameter as it approaches the end surface. A joint (11a) is formed. The peripheral surface of the engaging portion (11a) is in contact with the inner wall surface of the mounting hole provided in the throw-away tip (100).

What is necessary is just to select suitably the kind of screw formed in the outer peripheral surface of an external thread part (12) from well-known things. And the notch part (12a) of two or more places, preferably six places or less is formed in the outer peripheral part of the external thread part (12) at one place or a space | interval of the circumferential direction. The reason why the notches (12a) are formed in six or less is to facilitate molding. The notch (12a) extends from the distal end surface (12c) of the male screw portion (12) toward the head (11) side along the axis (CL1) of the clamp screw (10). For example, FIGS. 1C and 1D show flat surfaces formed symmetrically at two locations with respect to the axis (CL1). Thus, the notch (12a) is preferably formed of a flat surface in terms of ease of molding, but the cross section is formed of a curved surface having a convex arc shape toward the axis (CL1). (Not shown).

On the other hand, as illustrated in FIG. 2, the bottom surface (201) of the tip seat (200) on which the throw-away tip (100) is placed is provided with a female screw hole (20) screwed into the clamp screw (10). The female screw hole (20) is formed with a female screw portion (22) over a predetermined length from the mouth to the bottom of the hole on the inner wall surface of the pre-drilled pilot hole (21). When the throwaway tip (100) is fixed to the tip seat (200), the female screw portion (22) is formed at least deeper than the distal end surface (12c) of the male screw portion (12) of the clamp screw (10). The In addition, an internal thread part (22) may be formed in the back of the counterbore hole provided in the opening | mouth of the internal thread hole (20).

Furthermore, two or more, preferably six or less cutout portions (22a) are formed at one circumferential position of the female screw portion (22) or at an interval. The reason why the notches (22a) are formed in six or less is to facilitate molding. The notch (22a) extends from the mouth of the female screw portion (22) toward the bottom of the hole along the axis (CL2) of the female screw hole (20). For example, FIG. 2 (a) shows a groove-shaped notch (22a) having a U-shaped cross section formed symmetrically at two locations with respect to the axis (CL2). In addition to this, the cross-sectional shape of the notch (22a) can be changed to a U shape, a V shape, or the like (not shown).

At least one shaft center (CL1, CL2) of notches (12a, 22a) formed in the male screw portion (12) of the clamp screw (10) and the female screw portion (22) of the female screw hole (20), respectively. The length (L1, L2) in the direction is such that when the throw-away tip (100) is screwed onto the tip seat (200) as shown in FIG. The length is shorter than the length (L) to be screwed into the portion (22). More specifically, the length is set in the range of 30% to 70% of the screwed length (L). All the peripheral thread portions (12c, 22c) are formed in the remaining portion excluding the notches (12a, 22a) in the axial center (CL1, CL2) direction, and the notches (12a, 22a) are excluded in the circumferential direction. In the remaining portion, non-notched portions (12b, 22b) are formed. In addition, it is preferable that each notch part (12a, 22a) formed in the said external thread part (22) and the said internal thread part (22) is formed in the substantially equal length.

When viewed from the axial center (CL1, CL2) direction of the clamp screw (10) and the female screw hole (20), the male screw portion (12) of the clamp screw (10) and the female screw portion (22) of the female screw hole (20) are formed. The notch portions (12a, 22a) have a slightly larger circumferential formation range than the non-notch portions (12b, 22b) formed in the mating screw portions (12, 22) corresponding to the notch portions (12a, 22a). It is. Specifically, the circumferential formation range of the respective notches (12a, 22a) is 100 of the circumferential formation range of the non-notched portions (12b, 22b) of the corresponding threaded portion (12, 22). It is preferable to set it in the range exceeding 150% and not more than 150%. Or, when the range cut out by one notch (12a, 22a) on the circumference of the effective diameter of the male screw part (12) and the female screw part (22) is represented by a central angle (θ1, θ3), The central angles (θ1, θ3) are preferably set in a range of 20 ° to 315 °, and when two or more notches are formed, the sum of the central angles (θ1, θ3) is 40. It is preferably set in the range of ° to 315 °.

A method of attaching the throw-away tip (100) to the tip seat (200) in the throw-away cutting tool having the clamp screw (10) and the female screw hole (20) will be described below. As illustrated in FIGS. 3A and 3B, the mounting holes that penetrate the upper and lower surfaces (101, 102) of the throw-away tip (100) placed on the bottom surface (201) of the tip seat (200). The clamp screw (10) is inserted into (104), the axial centers (CL1, CL2) of both the clamp screw (10) and the female screw hole (20) are substantially aligned, and the clamp screw (10) in the circumferential direction. The notch part (12a) formed in the male screw part (12) and the non-notch part (22b) formed in the female screw part (22) of the female screw hole (20) are substantially matched, and the clamp screw (10) Is inserted from the mouth of the female screw hole (20) by a predetermined length along the axis (CL2) direction of the female screw hole without rotating the screw. The predetermined length is the length (L1, L2) in the direction of the axis (CL1, CL2) of each notch (12a, 22a), but the lengths (L1, L2) are different. Is the shorter of the two.

Then, by screwing the clamp screw (10) inserted into the female screw hole (20), as illustrated in FIGS. 4 (a) and (b), the male screw portion (12) and the female screw hole of the clamp screw (10). Each non-notched part (12b, 22b) formed in the female thread part (22) of (20) is the entire peripheral thread part (12c, 22c) and / or non-notched part (12b) of the mating screw part (12, 22). , 22b). The screwed clamp screw (10) has a convex curve in which the peripheral surface of the engaging portion (11a) formed on the head (11) forms the inner wall surface of the mounting hole (104) of the throw-away tip (100). By pressing the surface (104a), the throw-away tip (100) is pressed and fixed toward the bottom surface (201) of the tip seat (200) and the wall surface (202) raised from the bottom surface.

Conversely, when removing the throw-away tip (100) from the tip seat (200), the procedure may be the reverse of the attachment method described above. That is, by rotating the clamp screw (10), the threaded engagement with the female screw hole (20) is released, and the notch (12a) and the female screw formed in the male screw portion (12) of the clamp screw (10) in the circumferential direction The non-notched portion (22b) formed in the female screw portion (22) of the hole (20) is made to substantially coincide with the clamp screw (10) along the axis (CL2) of the female screw hole (20). What is necessary is just to extract from the said female screw hole (20), without rotating.

As described above, according to the present throw-away cutting tool, the clamp screw (10) has its male screw portion (12) extending from the mouth of the female screw portion (22) of the female screw hole (20) to the notch portion (12a, 22a) can be inserted without being screwed (rotated) over the shorter length (L1, L2) of the length in the axial center (CL1, CL2) direction, and then the throw-away tip (100) is inserted. What is necessary is just to screw in a female screw hole (20) until it screw-fits to a chip seat (200). Therefore, the time required for the screwing operation by rotating the clamp screw (10) is shortened, and the attaching / detaching operation of the throw-away tip (100) accompanying the corner change and replacement of the throw-away tip (100) can be quickly performed.

At least one of the notch portions (12a, 22a) formed in the male screw portion (12) of the clamp screw (10) and the female screw portion (22) of the female screw hole (20) is a throw-away tip (100). Since the male screw portion (12) is formed to have a length shorter than the length (L) to be screwed into the female screw portion (22) when screwed into the chip seat (200), the male screw portion (12) or the non-cutout portion (12b, 22b) formed in at least one of the female screw portion (22), the entire circumferential screw portion (12c) partly formed in the mating screw portion (12, 22). , 22c), so that both are surely screwed together and will not come off.

When changing the corner of the throw-away tip (100), the throw-away tip (100) can be completely removed from the tip seat (200) by completely removing the clamp screw (10) from the female screw hole (20). Therefore, it becomes possible to easily and completely remove chips, cutting oil and the like attached to the throw-away tip (100) and the tip seat (200), and the throw-away tip (100) is damaged or the tip seat (200) is removed. Deformation can be prevented.

Moreover, the corner portion (23) of the throw-away tip (20) is located at a position located immediately in front of the rotational direction (T) of the tip seat (18) as in the conventional throw-away type face mill illustrated in FIG. Since there is no need to provide a recess (19) that is recessed on the inner peripheral side of the tool body (11) for allowing the tool to pass through, the strength of the tool body is not reduced.

In this throw-away cutting tool, when viewed from the axial center (CL1, CL2) direction of the clamp screw (10) and the female screw hole (20), the respective notches formed in the male screw portion (12) and the female screw portion (22). (12a, 22a) has a slightly larger circumferential formation range than the non-notched portions (12b, 22b) of the mating screw portions (12, 22) corresponding to the notched portions (12a, 22a). The workability of inserting / removing the clamp screw (10) into / from the female screw hole (20) can be performed easily and quickly. Here, the circumferential formation range of each notch part (12a, 22a) is 100% of the circumferential formation range of the non-notch part (12b, 22b) of the corresponding mating screw part (12, 22). Since it is set in the range of more than 150% and less than 150%, it is possible to avoid the formation range in the circumferential direction of the non-notched portions (12b, 22b) from becoming too small, and to reduce the tightening axial force of the clamp screw (10) and non-notched Damage to the parts (12b, 22b) can be prevented. When the range cut out by one notch (12a, 22a) on the circumference of the effective diameter of the male screw part (12) and the female screw part (22) is represented by center angles (θ1, θ3), the center The angles (θ1, θ3) are in the range of 20 ° to 315 °, or when two or more notches are formed, the sum of the central angles (θ1, θ3) is set in the range of 40 ° to 315 °. Even in this case, it is possible to avoid the formation range in the circumferential direction of the non-notched portions (12b, 22b) from being excessively small, the reduction of the tightening axial force of the clamp screw (10), and the non-notched portions (12b, 22b). Damage can be prevented.

The length (L1, CL2) in the axial center (CL1, CL2) direction of each notch (12a, 22a) formed in the male screw portion (12) of the clamp screw (10) and the female screw portion (22) of the female screw hole (20). When L2) is less than 30% of the length (L) in which the male screw portion (12) is screwed into the female screw portion (22) when the throw-away tip (100) is screwed to the tip seat (200). The desired effect of shortening the time required for screwing and removing the clamp screw (10) is not sufficiently obtained, and when it exceeds 70%, the male screw portion (12) and the female screw portion (22) are formed respectively. The non-notched portions (12b, 22b) and the entire peripheral thread portions (12c, 22c) may be locally deformed or damaged due to a high load.

The length (L1, CL2) in the axial center (CL1, CL2) direction of each notch (12a, 22a) formed in the male screw portion (12) of the clamp screw (10) and the female screw portion (22) of the female screw hole (20). When the length L2) is substantially equal, when the clamp screw (10) inserted into the female screw hole (20) is screwed in, both non-notched portions formed in the male screw portion (12) and the female screw portion (22) (12b, 22b) immediately engages with the other-side circumferential threaded portion (12c, 22c), so that the clamp screw (10) and the female screw hole (20) are strongly screwed together and the throw-away tip ( 100) can be prevented from being reduced, and the concentration of load on the non-notched portions (12c, 22c) can be alleviated and damage can be suppressed.

Next, another throw-away cutting tool to which the present invention is applied will be described with reference to the drawings. FIG. 5 is a view for explaining a clamp screw used in the present throw-away type cutting tool, wherein (a) is a plan view, (b) is a front view, (c) is a side view, and (d) is an FF line. It is sectional drawing. 6 is a longitudinal sectional view showing a state in which the throw-away tip is fixed to the tip seat with the clamp screw shown in FIG.

As illustrated in FIG. 5, a substantially cylindrical protrusion (14) is formed that protrudes along the axis (CL 1) from the distal end surface (12 c) of the male screw portion (12) of the clamp screw (10). An urging means (30) such as a coil spring (30A) is mounted around the protrusion (14). The coil spring (30A) is in a free height state where no load is applied, and one end of the coil spring (30A) comes into contact with the front end surface (12c) of the male screw portion (12), while the other end is the protrusion (14). It is mounted so as to protrude in the axial center (CL1) direction from the front end surface.

On the other hand, in the female screw hole (20) screwed into the clamp screw (10), as illustrated in FIG. 6, a coil spring (30A) is provided on the inner side of the female screw part (22) of the female screw hole (20). A recess (25) for receiving is provided. In the present throw-away cutting tool, the recess (25) is formed by a blind hole having a diameter slightly larger than the outer diameter of the coil spring (30A). When the clamp screw (10) is screwed into the female screw hole (20), the coil spring (30) has the tip surface (12c) of the male screw portion (12) of the clamp screw (10) and the bottom surface (25a) of the concave portion (25). , The tip end surface (12a) of the male screw portion (12) of the clamp screw (10) is urged toward the head (11) side.

By providing the above urging means, when the clamp screw (10) is removed from the female screw hole (20), the male screw portion (12) of the clamp screw (10) and the female screw portion (22) of the female screw hole (20). As soon as the threaded state is released and the notched part (12a) of the male threaded part (12) and the non-notched part (22b) of the female threaded hole (20) substantially coincide with each other in the circumferential direction, the clamp screw (10) Since it is pushed up in the direction of extraction from the female screw hole (20), the extraction operation of the clamp screw (10) can be performed more easily and quickly.

The throw-away cutting tool described above can be applied to all throw-away cutting tools in which a throw-away tip (10) made of a hard material such as cemented carbide is detachably attached to a tool body. 7-10 is a figure which illustrates the throwaway type cutting tool to which this invention is applied, in each figure, (a) is a front view side view, (b) is a front view. For example, a throw-away turning tool represented by a throw-away tool illustrated in FIG. 7, a throw-away face mill illustrated in FIG. 8, a throw-away end mill illustrated in FIG. 9, a throw-away side cutter and a throw not illustrated in FIG. The present invention can be applied to a throw-away type rolling tool such as an away-type boring cutter, or a throw-away type drilling tool such as a throw-away drill illustrated in FIG. 10 and a throw-away type reamer (not shown).

According to the throw-away type turning tool, the turning tool, the drilling tool and the like to which the present invention is applied, the expected effect of shortening the time required for the above-described removal operation of the clamp screw (10) can be obtained. A significant effect is obtained with a throw-away type rolling tool and a drilling tool in which a large number of throw-away tips are mounted on the main body. Further, since the throwaway tip can be firmly fixed with a simple structure and downsizing, it is suitable for a throwaway cutting tool using a small throwaway tip. Further, in the throw-away type rolling tool and the drilling tool in which the tool body rotates, an effect of preventing the throw-away tip from moving or scattering in the centrifugal force direction due to the centrifugal force can be obtained.

Next, an embodiment of the replacement work of the throw-away tip in the throw-away type face mill of the present invention will be described. The throw-away type face mill of the present invention shown in FIG. 11 has a tool diameter of 200 mm, 15 blades, that is, 15 throw-away tips attached to the tool body. As shown in FIG. 1, the clamp screw (10) for fixing these throw-away tips (100) is formed on the outer peripheral portion of the male screw portion (12) with a notch formed by two flat surfaces at intervals in the circumferential direction. (12a). The female screw hole (20) provided in the bottom surface (201) of the tip seat (200) of the tool body corresponds to the clamp screw (10) on the inner peripheral part of the female screw part (12) as shown in FIG. It has a notch part (22a) in two positions of the circumferential direction. The male screw portion (12) of the clamp screw (10) and the female screw portion (22) of the female screw hole (20) are M3.5 coarse threads, and the axial centers of the notches (12a, 22a) formed on both sides ( CL1 and CL2) are equal in length and 50% of the length (L) at which the male screw portion (12) is screwed into the female screw portion (22) when the throw-away tip (100) is screwed. It is formed. On the other hand, the comparative throw-away type face mill of the comparative product is formed by forming a general male screw portion and a female screw portion in which the clamp screw and the female screw hole do not have the above-described notch portion. Other configurations are the same as those of the present invention.

In the above-described product of the present invention and the comparative product, after removing all 15 throwaway tips previously attached to the tool body, the work time required for reattachment was measured. In the operation of detaching the throw-away tip, in the comparative product, it is necessary to rotate the clamp screw a number of times over the length of inserting the male screw portion of the clamp screw into the female screw portion of the female screw hole. For the product, it is only necessary to screw in and remove the clamp screw by about half the length of the insertion, so that the working time is reduced by 35% compared to the comparative product as shown in FIG. It was.

It is a figure explaining the clamp screw used for the throw away type cutting tool to which this invention is applied, (a) is a top view, (b) is a front view, (c) is a side view, (d) is a bottom view. is there. It is a figure explaining the internal thread hole screwed together with the clamp screw shown in FIG. 1, (a) is the figure seen from the axial center direction, (b) is an AA sectional view, (c) is BB. It is line sectional drawing. It is a figure which shows the state which inserted the clamp screw shown in FIG. 1 in the internal thread hole shown in FIG. 2, (a) is a longitudinal cross-sectional view, (b) is CC sectional view taken on the line. It is a figure which shows the state which fixed the throw away tip with the clamp screw shown in FIG. 1, (a) is a longitudinal cross-sectional view, (b) is DD sectional view, (c) is EE sectional view FIG. It is a figure explaining the clamp screw used for the other throwaway type cutting tool to which this invention is applied, (a) is a top view, (b) is a front view, (c) is a side view, (d) is F FIG. It is a longitudinal cross-sectional view which shows the state which fixed the throw away tip to the chip | tip seat with the clamp screw shown in FIG. It is a figure of the throw away type | formula bite to which this invention is applied, (a) is a front view side view, (b) is a front view. It is a figure of the throw away type front milling to which the present invention is applied, (a) is a tip side view, and (b) is a front view. It is a figure of the throw away type end mill to which the present invention is applied, (a) is a side view in front end view, and (b) is a front view. It is a figure of the throw away type drill which applied the present invention, (a) is a tip side view, and (b) is a front view. It is a figure explaining the Example of the throwaway type front milling to which this invention is applied. It is a figure explaining the conventional throw away type byte. It is a figure explaining the other conventional throwaway type front milling machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Clamp screw 11 Clamp screw head part 11a Engagement part 12 Clamp screw male thread part 12a Male thread part notch part 12b Male thread part non-notch part 12c Male thread part circumferential thread part 20 Female thread hole 22 Female thread part 22a female thread part 22a Notched part 22b of female thread part Non-notched part 22c of female thread part Fully threaded part 30 of female thread part Energizing means (coil spring)
100 Throw-away tip 101 Upper surface of throw-away tip 102 Lower surface of throw-away tip 104 Throw-away tip mounting hole 200 Tip seat 201 Bottom surface of tip seat CL1 Center axis of clamp screw CL2 Center axis of female screw hole L1 Notch formed in male thread Length L2 Length L of notch formed in the female threaded part Length that the male threaded part is screwed into the female threaded part

Claims (6)

The lower surface of the throwaway tip is seated on the bottom surface of the tip seat provided on the tool body, and the clamp screw inserted through the mounting hole penetrating the upper and lower surfaces of the throwaway tip is inserted into the female screw hole provided on the bottom surface of the tip seat. In the throw-away cutting tool in which the throw-away tip is detachably attached to the tool body by screwing,
On the outer peripheral portion of the male screw portion of the clamp screw, a notch portion extending along the axial direction of the clamp screw and opening at the front end surface of the male screw portion is provided at one place in the circumferential direction or at two or more places at intervals. The inner thread portion of the female screw hole is formed along the axial direction of the female screw hole at a circumferential position corresponding to a non-notched portion that is a remaining portion excluding the notched portion of the male screw portion. Forming a notch that extends and opens at the mouth of the female thread,
Furthermore, the formation range in the circumferential direction of each notch formed in the male screw part and the female screw part is larger than the formation range in the circumferential direction of the non-notch part of the mating screw part corresponding to the notch part. A throw-away type cutting tool characterized by that. When the throwaway tip is screwed onto the tip seat, at least one of the notch portions formed in the male screw portion of the clamp screw and the female screw portion of the female screw hole, the male screw portion becomes the female screw portion. The throw-away cutting tool according to claim 1, wherein the throw-away cutting tool is shorter than a screwing length (L). The axial lengths (L1, L2) of the notches formed in the male screw portion of the clamp screw and the female screw portion of the female screw hole are set to the male screw when the throwaway tip is screwed to the tip seat. The throw-away cutting tool according to claim 1 or 2, wherein a length of the portion is in a range of 30% to 70% of a length (L) to be screwed into the female screw portion. 4. The axial lengths (L1, L2) of the notches formed in the male screw portion of the clamp screw and the female screw portion of the female screw hole are substantially equal lengths. A throw-away cutting tool according to item 1. The throw-away cutting tool according to any one of claims 1 to 4, further comprising an urging means for urging the clamp screw upward from the bottom of the female screw hole. The throwaway cutting tool according to any one of claims 1 to 5, wherein the throwaway cutting tool is any one of a throwaway turning tool, a throwaway rolling tool, and a throwaway drilling tool. Type cutting tool.

Images