JPH0512004U - Throwaway cutting tool - Google Patents

Abstract

(57) [Summary] [Structure] A mounting surface 12A is formed at the tip of the shank portion 12 made of cemented carbide along the longitudinal direction of the tool body 11, and a fitting hole 12B is formed in the mounting surface 12A. A flat plate-shaped chip mounting member 13 having a chip mounting seat 14 made of steel or a sintered alloy and having a fitting projection 13E is fixed to the mounting surface 12A. A clamp screw hole 13F is screwed from the bottom surface 14A of the chip mounting seat 14 to the fitting projection 13E. By inserting the clamp screw 16 into the chip 15 and screwing and fastening the clamp screw hole 13F into the clamp screw hole 13F. Insert the chip 15. [Effect] A high strength is secured against the cutting force F acting on the tip 15, and the cutting of the tip mounting member 13 is prevented,
Further, the rigidity at the tip of the tool is increased, and the vibration damping property is improved. Further, even when the screw-on type is used, it is not necessary to cut a screw in the shank portion 12, and the rigidity of the tool tip can be maintained.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a tool, a boring bar, an end mill, etc. in which a throw-away tip (hereinafter referred to as a tip) is attached to a tip mounting seat formed at the tip of a tool body, and in particular, a shank portion is made of a cemented carbide. The present invention relates to a throw-away type cutting tool in which the tip mounting seat portion is made of steel or a machinable sintered alloy.

[0002]

[Prior Art]

 Cutting tools such as cutting tools, boring bars, and end mills are known to use cemented carbide for the shank in order to improve vibration resistance and reduce chattering. However, in a throw-away type cutting tool that uses a tip for the cutting edge, it is difficult to form the tip mounting seat if the entire tool body is made of cemented carbide, so the tip of the tool body to which this tip is mounted is difficult to form. It is common practice to form a part from steel or a machinable sintered alloy and attach it to a cemented carbide shank.

FIG. 9 and FIG. 10 show an example of such a throw-away type cutting tool. In these figures, the tool body 1 is composed of a cylindrical shank portion 2 made of cemented carbide and a tip mounting member 3 made of steel or a sintered alloy, and the tip end portion of the tip mounting member 3 is formed. The tip 5 is mounted on the tip mounting seat 4 formed on the above and is fixed by the clamp mechanism 6. The tip mounting member 3 is formed into a columnar shape having the same diameter as the shank portion 2 on the base end 3A side, and a semicircular cross section cut off on the tip 3B side by a plane 3C including the axis O of the cylinder. The tip end surface of the tip mounting member 3 is fixed to the tip of the tool body 1 by brazing the tip end surface of the shank portion 2. Then, the chip mounting seat 4 and the clamp mechanism 6 are provided on the plane 3C of the chip mounting member 3.

The tip 5 is a positive type tip having a substantially equilateral triangle shape in a plan view from the one end face 5A side which is a rake face in this example, and the one end face 5A and three peripheral surfaces serving as flank faces. A cutting edge 5C is formed at each of the intersecting ridges formed by 5B. On the other hand, the chip mounting seat 4 on which the chip 5 is mounted is formed to be lower than the flat surface 3C by one step, and the chip mounting seat bottom surface 4A and the chip mounting seat bottom surface 4A which stands upright from the flat surface 3C. It is composed of one chip mounting seat wall surface 4B, 4C, and the narrow angle formed by these chip mounting seat wall surfaces 4B, 4C is set to 60 °. Further, the tip mounting seat 4 is formed so that the cutting edge 5C of the tip 5 with the tip 5 mounted thereon is perpendicular to the axis O and slightly protrudes in the direction of the axis O from the tip of the tip mounting member 3. Has been done.

In addition, the clamp mechanism 6 presses the claw 6C provided at the tip of the clamp piece 6B against the one end surface 5A of the chip 5 mounted on the chip mounting seat 4 by screwing in the clamp screw 6A. The other end surface 5D serving as the seating surface of the chip 5 is brought into close contact with and fixed to the above-mentioned chip mounting seat bottom surface 4A by pressure. Then, two of the three peripheral surfaces 5B of the chip 5 are brought into contact with the chip mounting seat wall surfaces 4B, 4C, and then the chip 5 is fixed by the clamp mechanism 6 so that the chip 5 is fixed. The position is determined. Reference numeral 4D in the drawing is a relief portion for avoiding interference between the corner portion formed by the peripheral surfaces 5B of the chip 5 and the chip mounting seat 4.

[0006]

[Problems to be solved by the device]

 By the way, in the throw-away type cutting tool having such a structure, as described above, the tool body 1 is brazed to the tip end surface of the cylindrical shank portion 2 and the base end surface of the tip mounting member 3 having the same diameter as the tool body 1. It is configured by being fixed by such as. Therefore, both brazing surfaces are formed in a direction perpendicular to the tool axis O. On the other hand, in the cutting by such a throw-away type tool, the cutting force F acting on the tool at the time of cutting acts in the direction perpendicular to the axis O as shown by the white arrow in FIG. Therefore, in the case of the above-mentioned conventional example, the direction in which the cutting force F acts is the same as the direction formed by the joint surface between the shank portion 2 and the tip mounting member 3, and the cutting force F is It acts in the direction of shearing. Therefore, when an excessive cutting force is applied to the tip mounting member 3 via the tip 5, the tip mounting member 3 may be separated from the shank portion 2 from this joint surface. Even if the cutting tool is not divided, the portion occupied by the tip mounting member 3 made of steel or the like is inevitably relatively large in the cutting tool having the above-mentioned configuration, which reduces the rigidity of the tool at the tip of the tool. Is inevitable. This may impair the anti-vibration property and cause vibration and chatter during cutting.

On the other hand, in order to avoid such a situation, for example, the tip of the shank portion 2 is formed into a convex surface protruding in a V shape, and the base end surface of the chip mounting member 3 is formed into a V-shaped valley shape matching the convex surface. Alternatively, there is also proposed a cutting tool in which the tip of the shank portion 2 has a conical convex surface and the above-mentioned base end surface has a concave surface conforming to this. However, in such a cutting tool, there is a problem in that the convex surface and the concave surface must be accurately matched with each other, it is extremely difficult to form these surfaces, and brazing is also difficult.

[0008]

[Means for Solving the Problems]

 The present invention has been made in order to solve such a problem, and a chip mounting member is formed in a flat plate shape, and a chip mounting seat is formed on one surface side of the chip mounting member. On the other surface, a fitting protrusion is formed so as to project from the back side of the bottom surface of the tip mounting seat, and a clamping screw hole is screwed from the bottom surface of the tip mounting seat to this fitting projection, while the shank portion is A mounting surface is formed at the tip of the shank along the longitudinal direction of the shank, and a fitting hole for fitting the fitting protrusion is formed in the mounting surface. After the protrusion is inserted and the other surface is in close contact with the mounting surface to fix the chip mounting member, insert the clamp screw into the chip, and screw the clamp screw into the clamp screw hole to mount the chip. It is characterized by being attached to the tip mounting seat It is.

[0009]

[Action]

 In the present invention, the tip mounting member is formed in the shape of a flat plate, and the mounting surface on which the tip mounting member is mounted is formed along the longitudinal direction of the shank portion, so that it is perpendicular to the axis of the tool body. The cutting force acting in the direction also acts in the direction perpendicular to the mounting surface. That is, a load is applied to a direction perpendicular to the load applied during cutting, and the cutting force can be prevented from acting in the direction of shearing the tip mounting member and the shank portion. Further, by forming the mounting surface on which the chip mounting member is fixed along the longitudinal direction of the shank part, the shank part made of cemented carbide extends to the vicinity of the cutting edge of the chip protruding from the tool tip. Therefore, it is possible to improve the rigidity of the cutting tool at the tip of the tool.

[0010]

【Example】

 1 to 5 show a tip portion of a throw-away type cutting tool according to an embodiment of the present invention. As shown in these figures, also in this embodiment, the tool body 11 is composed of the shank portion 12 and the tip mounting member 13, and the tip 15 is mounted on the tip mounting seat 14 formed at the tip of the tool body 11. It has been installed.

The shank portion 12 is a substantially columnar member made of cemented carbide as in the conventional example, but its tip portion does not include the tool axis O and is a flat surface extending in a direction parallel to the tool axis O. A portion including the tool axis O is cut out by this, whereby a substantially square mounting surface 12A of the tip mounting member 13 parallel to the tool axis O is formed at the tip of the shank portion 12. .. The base end side of the mounting surface 12A is a surface that once rises in a direction perpendicular to the mounting surface 12A and then is inclined and continues to the outer peripheral surface of the shank portion 12.

On the other hand, the chip mounting member 13 mounted on the mounting surface 12A has an outer shape formed into a substantially square flat plate shape corresponding to the planar shape of the mounting surface 12A, and is made of steel or machinable calcination. It is made of a material having higher toughness than the cemented carbide forming the shank portion 12, such as bond gold. Then, the chip mounting member 13 is recessed on the one surface 13A side so as to be further lowered from the one surface 13A to the inner side in the thickness direction of the chip mounting member 13, and the one surface 13A and the chip mounting member 13 The tip mounting seat 14 is formed so as to open on the peripheral surface 13B of the member 13 on the tip side of the tool body 11 and the peripheral surface 13C which intersects with the peripheral surface 13B.

Here, in this embodiment, the tip 15 mounted on the tip mounting seat 14 is a positive type having a substantially equilateral triangle shape in plan view from the one end face 15A side which is a rake face, as in the above-mentioned conventional example. Cutting edges 15C are formed at the intersecting ridges formed by the one end surface 15A and the three peripheral surfaces 15B serving as flanks. Further, a mounting hole 15D into which a clamp screw 16 to be described later is inserted is provided in the tip 15 in the thickness direction of the tip 15 from the center of the one end surface 15A.

Correspondingly, the bottom surface 14 A of the chip mounting seat 14 formed on the chip mounting member 13 has a substantially equilateral triangle shape in plan view from the thickness direction of the chip mounting member 13. It is molded. Further, the two wall surfaces 14B of the chip mounting seat 14 connected from the bottom surface 14A to the one surface 13A of the chip mounting member 13 are formed such that the narrow angle thereof is 60 °, and each wall surface 14B is The edge portion on the side of the one surface 13A is slightly inclined so as to widen in accordance with the clearance of the peripheral surface 15B of the chip 15. Further, in the tip mounting seat 14 with the tip 15 mounted, one cutting edge 15C of the tip 15 projects from the peripheral surface 13B on the tip side of the tip mounting member 13 and the one cutting edge 15C. Are formed so as to be arranged in a plane perpendicular to the tool axis O. Reference numeral 14C in the drawing is a relief for avoiding interference between the corners of the peripheral surface 15B of the chip 15 and the chip mounting seat 14.

Further, in the present embodiment, the other surface 13D of the chip mounting member 13 is provided on the other surface 13D opposite to the one surface 13A and from the back surface portion of the bottom surface 15A of the chip mounting seat 15 to the other surface 13D. A cylindrical fitting projection 13E is formed integrally with the chip mounting member 13 so as to project vertically. On the other hand, on the mounting surface 12A at the tip of the shank portion 12, at the position corresponding to the fitting protrusion 13E when the chip mounting member 13 is fixed, the fitting protrusion 13E is perpendicular to the mounting surface 12A. A fitting hole 12B having a circular cross section that can be fitted is provided. Here, in the fitting protrusion 13E, the center line of the cylinder formed by the fitting protrusion 13E is formed so as to penetrate through the center of the tip 15 when the tip 15 is mounted on the tip mounting seat 14. It is set so as to be slightly eccentric from the center line of the mounting hole 15D to the corner of the chip mounting seat 14 in which the above-mentioned escape 14C is formed. Further, the fitting hole 12B is formed so as to penetrate from the mounting surface 12A toward the outer peripheral surface of the shank portion 12, and the shank portion 12 of the fitting protrusion 13E fitted in the fitting hole 12B. The tip end surface exposed on the outer peripheral surface is formed in a protruding curved shape so as to be smoothly continuous with the outer peripheral surface. Further, in this embodiment, the tip end of the fitting projection 13E is provided on the fitting projection 13E of the chip mounting member 13 coaxially with the center line of the fitting projection 13E from the bottom surface 14A of the chip mounting seat 14. A clamp screw hole 13F that is screwed into the clamp screw 16 is screwed toward.

In this embodiment, such a chip mounting member 13 has its fitting projection 13E fitted in the fitting hole 12B, and its peripheral surface 13G on the base end side in the tool axis O direction is shank part. 12 is attached to the surface 12C perpendicular to the tool axis O on the base end side of the mounting surface 12A, the other surface 13D is brought into close contact with the mounting surface 12A, and the other surface 13D and the mounting surface 12A are attached. It is fixed to the tip of the shank portion 12 by brazing. Then, the chip 15 is attached to the chip mounting seat 14 formed on the fixed chip mounting member 13, and two of the three peripheral surfaces 15B are brought into contact with the two wall surfaces 14B of the chip mounting seat 14. It is mounted in a state of being in contact with each other, the clamp screw 16 is inserted into the mounting hole 15D, and the clamp screw 16 is fixed by screwing it into the clamp screw hole 13F formed in the fitting projection 13E.

According to the throw-away type cutting tool having such a configuration, the cutting force F acting on the tip 15 during cutting passes from the tip 15 through the bottom surface 14A of the tip mounting seat 14 to a shank made of cemented carbide. The cutting force F is received by the mounting surface 12A formed along the direction parallel to the tool axis O of the portion 12, that is, along the longitudinal direction of the shank portion 12, and this cutting force F is generated between the shank portion 12 and the tip mounting member 13. It is possible to avoid acting on the joint surface in the direction of shearing it. Therefore, it is possible to secure a high strength against the cutting load, and it is possible to prevent the cutting of the tool and the like even if an excessive load occurs. Further, since the shank portion 12 made of cemented carbide extends to the vicinity of the cutting edge 15C as the tip mounting seat bottom surface 12A and holds the tip 15, high rigidity can be secured even at the tool tip portion, Vibration resistance is improved, and it is possible to more effectively suppress chatter and vibration during cutting work.

Further, according to the throw-away cutting tool having the above structure, the fitting protrusion 13E formed on the tip mounting member 13 is fitted in the fitting hole 12B formed on the mounting surface 12A. The tip mounting member 13 is fixed to the shank portion 12. For this reason, the joint between the shank portion 12 and the tip mounting member 12 can be made stronger and more reliable, and the strength against a cutting load can be further improved. Further, the position of the chip mounting seat 14 formed on the chip mounting member 13 can be accurately set by fitting the fitting protrusion 13E and the fitting hole 12B formed on the mounting surface 12A. As a result, the cutting edge 15C of the tip 15 can be more accurately positioned. Further, in this embodiment, since the tip mounting member 13 is fixed in a state in which one peripheral surface 13G of the tip mounting member 13 is in contact with the surface 12C of the shank portion 12 which is perpendicular to the tool axis O, the fitting protrusion 13 is fixed. The position of the chip mounting seat 14 can be set more accurately in combination with the fitting of the portion 13E and the fitting hole 12B, and the surfaces of the chip mounting members 14 become non-rotatable so that the position of the chip mounting member 13 is improved. You can prevent it from slipping.

Furthermore, in the throw-away type cutting tool having the above-mentioned configuration, the mounting hole 15D is formed in the tip 15, the clamp screw 16 is inserted into the mounting hole 15D, and the clamp screw 16 is screwed into the tip mounting seat 14. Even when the screw 15 is screwed into the provided clamp screw hole 13F and then the clamp screw 16 is tightened to directly fix the chip 15, the shank portion 12 made of cemented carbide has the above-mentioned clamp screw. The advantage that it is not necessary to form the hole 13F can be obtained. That is, when the chip mounting member 13 is formed in a flat plate shape and the mounting surface 12A on which the chip mounting member 13 is mounted is formed along the longitudinal direction of the shank portion 12, the chip 15 is fixed by screw-on. Has to increase the wall thickness of the chip mounting member 13 or form a clamp screw hole 13F through the chip mounting member 13 to the shank portion 12. However, increasing the wall thickness of the tip mounting member 13 means that the wall thickness of the shank portion 12 at the tip of the tool body 11 becomes small without repairing, and the tool rigidity at the tip is maintained. It is not preferable to do. On the other hand, it is not easy to form a screw hole in the high-hardness shank portion 12 made of cemented carbide. On the other hand, in the throw-away type cutting tool having the above-described structure, the clamping screw hole 15D is screwed into the fitting protrusion 13E integrally formed with the tip mounting member 13 made of steel or calcined-bonded gold. The chip 15 can be attached by screw-on without providing a screw hole in the shank portion 12 made of hard alloy. Moreover, since the wall thickness of the shank portion 12 at the tool tip portion does not become small, the rigidity at the tool tip portion can be sufficiently maintained. In this embodiment, the center line of the fitting projection 13E is eccentric to the mounting hole 15D of the chip 15 on the side of the clearance 14C of the chip mounting seat 14, and therefore the fitting projection 14E is formed on the fitting projection 14E. Since the center of the clamp screw hole 13F is also eccentric to the side of the relief 14C, the peripheral surface 15B of the clamp screw hole 13F is strongly pressed by the chip mounting seat wall surface 14B to fix the chip 15 more firmly. The advantage of being able to do is obtained.

Next, FIGS. 6 to 8 show another embodiment of the present invention, in which the same parts as those of the embodiment shown in FIGS. To do. In the present embodiment, the chip mounting member 13 of the embodiment shown in FIGS. 1 to 5 is mounted on the mounting surface 12A of the shank portion 12 by brazing, while the chip mounting member 13 has its thickness. A screw hole 17 is screwed in the direction, and a through hole 18 and a spot facing portion 19 are formed at a position corresponding to the mounting surface 12A of the screw hole 17, and a set screw 20 is inserted and screwed into these. This is characterized in that the chip mounting member 13 is pulled in and fixed to the mounting surface 12A side.

Also in the indexable cutting tool having such a configuration, the tip mounting member 13 is formed in a flat plate shape, the mounting surface 12A is formed in the longitudinal direction of the shank portion 12, and is formed on the mounting surface 12A. Since the chip mounting member 13 is fixed in a state in which the fitting projection 13E formed on the chip mounting member 13 is fitted in the fitting hole 12B, the same effect as that of the above embodiment can be obtained. Furthermore, in this embodiment, since the chip mounting member 13 is screwed, the chip mounting member 13 can be easily removed and mounted, and even if the chip mounting member 13 is damaged, it is simply replaced. Therefore, the shank portion 12 can be used as it is. Further, by preparing the chip mounting member 13 in which the chip mounting seats 14 of various shapes are formed according to the shape of the chip 15, it is possible to mount a plurality of types of chips 15 on one shank portion 12. It will be possible.

In these embodiments, the chip mounting seat 14 is formed on the one surface 13A side of the flat plate-shaped chip mounting member 13 so as to be lowered by one step from the one surface 13A. Therefore, the portion from the bottom surface 14A of the chip mounting seat 14 to the other surface 13D of the chip mounting member 13 becomes a relatively thin portion. Here, if the wall thickness T of this portion is set too thin, the molding of the chip mounting member 13 becomes extremely difficult, which is not preferable. On the contrary, if the wall thickness T becomes too large, the wall thickness of the tip mounting member 13 itself becomes large, and the wall thickness of the shank portion 12 at the tool tip becomes small as described above, which is also not preferable. .. In view of these points, it is desirable that the wall thickness T be within the range of 0.1 mm to 2.0 mm.

[0023]

[Effect of the device]

 As described above, according to the present invention, since the mounting surface on which the tip mounting member is fixed is formed in the direction perpendicular to the direction in which the cutting force is applied, this cutting force is applied to the tip mounting member and the shank portion. It does not work to shear the joint surface with the cutting edge, high strength against the cutting force is secured, and even when an excessive cutting load is applied, it is possible to prevent the chip attachment part material from breaking. .. Furthermore, since the shank part made of cemented carbide extends to the vicinity of the cutting edge of the tool tip, the rigidity at the tool tip part increases, the vibration damping property is improved, and the occurrence of chattering etc. is effectively suppressed. It becomes possible.

Furthermore, by fitting the fitting protrusion formed on the chip mounting member and the fitting hole formed on the mounting surface of the shank portion, the joint between the two can be further strengthened. .. By screwing a clamp screw hole into this fitting protrusion, it is not necessary to form a screw hole in the shank portion made of cemented carbide and the tip of the tool body can be mounted even when the chip is screwed on. It is possible to maintain the rigidity at.

[Brief description of drawings]

FIG. 1 is a plan view of a tool tip portion according to an embodiment of the present invention.

FIG. 2 is a side view of the tip portion of the tool of FIG. 1 as seen obliquely from the upper side of one surface 13A of the tip mounting member 13.

3 is a front view of the tip end portion of the tool of FIG. 1 as seen from the tip end side in the direction of the axis O. FIG.

4 is a cross-sectional view taken along the line AA in FIG.

5 is a sectional view taken along line BB in FIG.

FIG. 6 is a plan view of a tool tip portion according to another embodiment of the present invention.

7 is a cross-sectional view taken along line CC of FIG.

8 is a cross-sectional view taken along the line DD in FIG.

FIG. 9 is a plan view showing a tip portion of a conventional throw-away type cutting tool.

10 is a side view of the conventional example shown in FIG.

[Explanation of symbols]

1, 11 Tool body 2, 12 Shank part 12A Mounting surface 12B Fitting hole 3,13 Chip mounting member 13A One surface of the chip mounting member 13 13B, 13C, 13G Peripheral surface of the chip mounting member 13 13D Chip mounting member 13 Other surface 13E Fitting protrusion 13F Clamp screw hole 4,14 Chip mounting seat 4A, 14A Bottom surface of chip mounting seat 14 4B, 4C, 14B Wall surface of chip mounting seat 14 5,15 Chip 15C Cutting edge 16 Clamp screw O Tool Axis T Bottom surface 1 of chip mounting seat 14 of chip mounting member 13
Thickness from 4A to the other surface 13D

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Junichi Saito 1-27-20 Shinagawa, Shinagawa-ku, Tokyo Mitsubishi Materials Corporation Tokyo Works

Claims (1)

[Scope of utility model registration request] 1. A tip attachment member made of steel or a sintered alloy is fixed to the tip of a rod-shaped shank portion made of cemented carbide, and a throw-away tip is attached to a tip attachment seat formed on the tip attachment member. In the throw-away cutting tool, the tip mounting member is formed into a flat plate shape, and the tip mounting seat is formed on one surface side thereof, and the tip mounting seat is formed on the other surface of the tip mounting member. A fitting protrusion is formed so as to protrude from the back side portion of the bottom surface, and a clamp screw hole is screwed into the fitting protrusion from the bottom surface of the chip mounting seat, while the tip of the shank portion has a shank portion of the shank portion. A mounting surface is formed along the longitudinal direction, and a fitting hole for fitting the fitting projection is formed in the mounting surface, and the fitting projection is fitted into the fitting hole, and then the other side is formed. Is the above mounting surface While fixing the tip mounting member in close contact with each other, insert a clamp screw into the throw-away tip, screw the clamp screw into the clamp screw hole, and attach the throw-away tip to the tip mounting seat. Characteristic throw-away type cutting tool.