JP2007175843A - Holder, tip, and cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a holder, a tip, and a cutting tool, wherein the tip is fixed to the holder without a positional shift even when the surface of the tip for forming a cutting edge thereon has been worn and deformed. <P>SOLUTION: The holder 4 includes a first constraining surface portion 10, a second constraining surface portion 12, and a pressing screw member 6. Because the tip 3 is pressed toward one direction A1 in the direction of its thickness by means of a constraining screw member 5, and is pressed toward one direction C1 in the direction of its width by means of a pressing screw member 6, the tip 3 can be firmly fixed to the holder 4. Undesirable displacement of the tip 3 with respect to the holder 4 is thereby prevented. Because the tip 3 is fixed by pressing a second separated surface portion 13 arranged in its longitudinal direction, the tip 3 is surely fixed to the holder 4 irrespective of the shape of the second separated surface portion 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a throw-away type cutting tool, and more particularly to a cutting tool holder and a tip for parting off.

  In the first conventional throw-away type cutting tool, a parallelogram-shaped tip is mounted on the tip holder portion of the shank by a clamp screw. Part of the first and second chip side surfaces constituting the acute angle part of the chip is supported by the first and second receiving surfaces of the chip holder part, respectively (see, for example, Patent Document 1 and Patent Document 2).

  A throw-away type cutting tool according to a second conventional technique includes a tip on which a cutting edge is formed and a holder on which the tip is detachably mounted. In a state where the chip is mounted on the holder, the chip is pressed against the holder by the screw member. Specifically, the chip side surface serving as a base formed on the chip is pressed against the holder side surface serving as a sheet formed on the holder. The chip side surface and the holder side surface extend perpendicular to the axis of the screw hole.

  An inclined surface that is inclined with respect to the axis of the screw hole is formed on each of the chip side surface and the holder side surface. When the chip is pressed against the holder by the screw member, the chip moves along an inclined surface formed on the side surface of the holder and moves in a direction inclined with respect to the axis of the screw hole. As a result, the lower surface of the chip serving as the support surface formed on the chip is pressed against the upper surface of the holder serving as the support wall surface formed on the holder. By pressing the chip against the holder with such a screw member, the two surfaces of the chip side surface and the chip lower surface formed on the chip are pressed against the holder side surface and the holder upper surface formed on the holder, respectively. (See, for example, Patent Document 3 and Patent Document 4).

JP-A-11-123603 Japanese Patent Laid-Open No. 2003-231006 Special table 2003-503218 gazette JP 2004-82321 A

  The throw-away tip used for cutting tools is generally changed to a new cutting edge position or replaced with a new throw-away tip when the cutting edge wears down and the cutting ability decreases. In some cases, the flank is re-polished to recover the cutting ability and can be used again. In this case, re-polishing can be repeated until the polishing allowance is eliminated. Further, in order to reduce the cost per corner (cutting edge), the chip is formed in a rotationally symmetrical shape with respect to a predetermined axis, and the chip is provided with two cutting edges. Even if one of the cutting blades becomes uncut by this, it is possible to use the other cutting blade by changing the corner and mounting.

  In the case of such a rewritable tip, when the flank of the tip is polished, the flank is scraped away and driven. Therefore, when a re-polished and tip-changed tip is used with the cutting tool of the first prior art, the flank which is the side surface of the tip is driven by polishing, so that the side surface of the tip cannot contact the receiving surface of the holder. The chip cannot be positioned with respect to the holder. As a result, the tip may be displaced with respect to the holder during cutting, and the work material cannot be processed into a desired shape with high accuracy.

  In the second conventional technique, even if the surface portion constituting the cutting edge is worn and deformed, the two surfaces of the chip side surface and the chip lower surface are pressed against the holder side surface and the holder upper surface, respectively. The chip can be fixed to the holder, but when the lower surface of the chip is pressed against the upper surface of the holder, the side surface of the chip moves in a state where it contacts the inclined surface formed on the side surface of the holder. Therefore, stress is applied to the inclined surface by repeatedly attaching and detaching the chip and cutting, and the side surface of the holder is easily worn. Further, when the chip is guided downward by the inclined surface formed on the side surface of the holder, a force directed upward from the chip is received. Therefore, the side surface of the holder is easily deformed by pressing the lower surface of the chip against the upper surface of the holder. Since the holder side surface is easily worn and deformed in this way, the holder life is short. Further, when the side surface of the holder is worn and deformed, the tip fixing position shifts with respect to the holder, and it is necessary to readjust the cutting position of the cutting tool.

  Therefore, an object of the present invention is to provide a holder, a chip, and a cutting tool that can fix the chip to the holder without displacement even if the surface part constituting the cutting edge is worn and deformed on the chip.

The present invention can attach and detach a substantially rectangular plate-shaped chip having a cutting edge, and is a holder that can be mounted with a chip in a chip mounting state in which the cutting edge of the chip protrudes from the outer peripheral surface portion,
A restraining screw that is a first constraining surface part that contacts one surface part in the thickness direction of the chip in a state where the chip is mounted, opens to a through hole formed in the chip and penetrates in the thickness direction of the chip, and is inserted into the through hole A first restraining surface portion in which a restraining screw hole into which the member is screwed is formed;
A second constraining surface part in contact with one surface part in the width direction of the chip in the chip mounting state;
And a pressing unit that presses one longitudinal surface of the chip toward the second restraining surface in a mounted state.

  Further, the present invention is characterized in that the pressing means presses a portion of one surface portion in the longitudinal direction of the chip and closer to one side in the width direction of the chip.

  Furthermore, the present invention is characterized in that, in the chip mounting state, the pressing means is perpendicular to the pressing direction to be pressed and a plane forming one surface portion in the longitudinal direction of the chip.

Furthermore, the present invention further includes a rear wall surface portion facing one surface portion in the longitudinal direction of the chip in a chip mounted state,
The pressing means includes a pressing screw member for pressing the chip with the chip mounted.
The rear wall surface portion is formed with a pressing screw hole that opens to face the second restraining surface portion and into which the pressing screw member is screwed.

  Further, according to the present invention, the pressing screw member is characterized in that a portion for pressing the chip is formed in a partial spherical shape.

Further, in the present invention, the pressing means is a pressing member in which a pressing member hole penetrating in the width direction of the chip is formed when the chip is mounted, and the third restraining surface portion facing one surface portion in the longitudinal direction of the chip is provided. A pressing member to be formed;
A screw member for a pressing member that is inserted through the hole for the pressing member and can be screwed along the width direction of the chip,
A screw hole for a pressing member into which the screw member for the pressing member is screwed is formed.

Furthermore, the present invention is a chip attached to the holder, wherein the chip is formed in a rotationally symmetrical shape with respect to the axis of the through hole.
Furthermore, the present invention is a cutting tool including the holder and the tip.

  According to the present invention, the holder includes a first restraining surface portion, a second restraining surface portion, and a pressing means. When the chip is mounted on the holder, one surface portion in the thickness direction comes into contact with the first constraining surface portion and one surface portion in the width direction comes into contact with the second constraining surface portion when the chip is mounted in the holder. In a state where the chip is mounted, the restraining screw member is inserted through the through hole, screwed into the restraining screw hole, and the restraining screw member is screwed to move the tip toward the thickness direction in one direction with respect to the holder. Press to fix. The pressing means presses one surface portion in the longitudinal direction of the chip toward the second restraining surface portion in the chip mounting state. Thereby, one surface portion in the width direction of the chip is pressed and fixed to the second restraint surface portion. Therefore, the chip is pressed toward the thickness direction by the restraining screw member and is pressed toward the width direction by the pressing means, so that the chip can be firmly fixed to the holder. Therefore, it is possible to prevent the tip from being undesirably displaced with respect to the holder.

  Since one of the chips in the longitudinal direction is pressed and fixed, the chip can be securely fixed to the holder regardless of the shape of one surface portion in the longitudinal direction of the chip. For example, even when the tip is formed in a rotationally symmetrical shape with respect to the axis of the through hole, the cutting blade formed on one side in the longitudinal direction is worn, and cutting is performed using the cutting blade formed on the other side in the longitudinal direction, Since one surface portion in the longitudinal direction is pressed and fixed by the pressing means, the chip can be securely fixed to the holder. As a result, it is possible to prevent a decrease in processing accuracy due to the displacement of the chip.

  According to the invention, the pressing means presses a portion on one surface in the longitudinal direction of the chip and closer to one side in the width direction of the chip. Therefore, the pressing means presses a portion close to the second restraining surface portion toward the second restraining surface portion, so that the rotation of the chip around the through hole axis can be reliably prevented. Therefore, the chip can be more firmly attached to the holder.

  Further, according to the present invention, in the pressing means, the pressing direction in which the pressing is performed and the plane forming one surface portion in the longitudinal direction of the chip are vertical. Therefore, the pressing force by the pressing means can be efficiently applied to one surface portion in the longitudinal direction of the chip without being reduced by the frictional force between the pressing device and one surface portion in the longitudinal direction.

  Furthermore, according to the present invention, the pressing means includes a pressing screw member and a pressing screw hole. The pressing screw member is screwed into a pressing screw hole formed in the rear wall surface portion. In the state where the chip is mounted, the rear wall surface portion faces one surface portion in the longitudinal direction of the chip. Therefore, when the pressing screw member is screwed, the one surface portion in the longitudinal direction of the chip is moved in the screwing direction of the pressing screw member. The tip portion comes into contact and presses the tip in the screwing direction. Therefore, the pressing means can be realized with a simple configuration.

  Furthermore, according to the present invention, the pressing screw member is formed such that the portion that presses the tip is a partial spherical shape. Thereby, even if the angle at which the chip is pressed is slightly swung, it can be surely pressed by point contact, and a stable restraining force can be obtained. In addition, since the region where the tip and the pressing screw member abut is smaller than when the tip pressing portion is flat, the pressing force acting on the tip by the pressing screw member is increased. And the chip can be more firmly fixed to the holder.

  Furthermore, according to this invention, a press means contains the press member in which the hole for press members is formed, and the screw member for press members. The pressing member screw member is inserted into the pressing member hole and is screwed into the pressing member screw hole. The screw member for the pressing member is screwed and screwed along the width direction of the chip. When the screw member for the pressing member is screwed, the third constraining surface portion of the pressing member comes into contact with one surface portion in the longitudinal direction of the chip, and the chip can be pressed toward the second constraining surface portion. Therefore, the pressing means can be realized by a pressing member that is displaced along the width direction. Even if the pressing member is damaged by contact with the chip, the holder of the present invention can be used continuously by replacing the pressing member with a new pressing member.

  Further, according to the present invention, since the chip is mounted on the holder and is formed in a rotationally symmetrical shape with respect to the axis of the through hole, the cutting blade formed on one side in the longitudinal direction is worn and the other side in the longitudinal direction is worn. It cuts using the cutting blade formed in. Even if one cutting edge in the longitudinal direction is worn, the one surface portion in the longitudinal direction is pressed and fixed by the pressing means, so that the chip is securely fixed to the holder. As a result, it is possible to prevent the displacement of the tip due to the use of both cutting edges in the longitudinal direction, to prevent the processing accuracy from being lowered, and to use the tip for a long time.

  Furthermore, according to the present invention, since the cutting tool includes the holder and the tip, it is possible to realize a cutting tool that can fix the tip to the holder without positional deviation regardless of the shape of one surface portion in the longitudinal direction of the tip. it can.

  Hereinafter, a plurality of embodiments for carrying out the present invention will be described with reference to the drawings. Portions corresponding to the matters described in the preceding forms in each embodiment are denoted by the same reference numerals, and overlapping description may be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

  FIG. 1 is an enlarged front view showing a part of the cutting tool 1 according to the first embodiment of the present invention. FIG. 2 is an exploded perspective view showing a part of the cutting tool 1, and FIG. 3 is a perspective view showing a part of the cutting tool 1. The cutting tool 1 according to the present embodiment is a tool for parting off, and performs cutting processing for dividing a rod-shaped work material or grooving processing for forming a circumferential groove in the rod-shaped work material. It is used to The cutting tool 1 includes a throw-away tip (hereinafter also referred to as “chip”) 3 on which a cutting edge 2 is formed, a holder 4 for detachably mounting the tip 3, and a constraint for fixing the tip 3 to the holder 4. The screw member 5 and the pressing screw member 6 are included.

  The holder 4 is formed in a rectangular parallelepiped shape extending along the axis L1, and a held portion held by a lathe is formed at a base end portion in the axial direction X that is a direction in which the axis L1 of the holder 4 extends. The tip 4a, which is the end of one X1 in the axial direction of the holder 4, is provided with a mounting portion 7 on which the tip 3 is mounted in a state where the cutting edge 2 of the tip 3 protrudes in the one X1 in the axial direction of the holder 4. The cutting tool 1 is configured with the tip 3 mounted on the holder 4. The holder 4 is made of a soft material such as steel compared to the chip 3, and is realized by, for example, alloy steel. Here, the soft material is a material having low deformation strength and wear strength.

  The lathe includes a moving drive unit that relatively moves and drives the cutting tool 1 that holds the held portion with respect to the workpiece clamped by the clamping unit included in the lathe, and the clamped workpiece is used as the axis of the holder 4. Rotation drive means for driving around the orthogonal rotation axis. The work material that is rotationally driven around the axis is brought into contact with the cutting tool 1 and is cut by the cutting edge 2 formed on the chip 3. As a result, the work material can be cut into a desired shape. Using the cutting tool 1, for example, grooving can be performed on a rod-shaped work material. When the cutting blade 2 of the chip 3 is worn or broken, the cutting tool 1 is restored by cutting the chip 3 by rotating it 180 degrees as will be described later or by replacing it with a new chip 3. be able to.

  The chip 3 is formed in a substantially rectangular plate shape, and a projection shape projected on a plane perpendicular to the thickness direction A is formed in a substantially parallelogram shape. A through hole 8 that penetrates in the thickness direction A is formed in the chip 3. The through hole 8 becomes a hole 8 for fixing the chip 3 to the holder 4 and is formed in a substantially cylindrical shape. The through hole 8 is formed at a central position in the longitudinal direction B and the width direction C of the chip 3. The tip 3 is formed in a 180-degree rotationally symmetric shape with respect to the reference axis L2, in other words, a 2-fold rotationally symmetric shape, with the axis of the through hole 8 being the reference axis L2. Therefore, when the chip 3 is viewed from an arbitrary direction, the same shape is obtained in the state rotated 180 degrees around the reference axis L2 and the state before the rotation.

  Hereinafter, the direction in which the reference axis L2 of the chip 3 extends is referred to as a thickness direction A. Of the directions perpendicular to the thickness direction A of the chip 3, the direction extending along the long side of the projected shape when projected onto the projection plane perpendicular to the reference axis L2 is referred to as the longitudinal direction B. A direction perpendicular to the thickness direction A and the longitudinal direction B of the chip 3 is referred to as a width direction C.

  In the chip mounting state in which the chip 3 is mounted on the holder 4, the bottom surface portion 9 of the thickness direction one A <b> 1 abuts on the first restraining surface portion 10 formed on the mounting portion 7 of the holder 4. Further, the second contact surface portion 11 on the one side C <b> 1 in the width direction of the chip 3 contacts the second restraint surface portion 12 formed on the mounting portion 7 of the holder 4. Further, the second spacing surface portion 13 on the one side B <b> 1 in the longitudinal direction of the chip 3 faces the rear wall surface portion 19 formed on the mounting portion 7 of the holder 4. Therefore, the chip 3 is mounted on the mounting portion 7 of the holder 4 in a state where at least the bottom surface portion 9 and the second contact surface portion 11 are in contact with the first restraint surface portion 10 and the second restraint surface portion 12, respectively.

  The chip 3 is the first contact surface portion 20 in the other width direction C2, and the first cutting edge 2a is formed on the edge of the other length direction B2. Further, the tip 3 is the second abutting surface portion 11, and the second cutting edge 2b is formed on the edge of the other longitudinal direction B1. In the chip mounting state, the first cutting edge 2 a and the second cutting edge 2 b are in a state of extending in a direction orthogonal to the axial direction of the holder 4.

  The tip 3 is formed with a first rake face 14 that is concave in the other widthwise direction C2 on the first abutting face part 20 that is continuous with the first cutting edge 2a, and the second abutting face part 11 that is continuous with the second cutting edge 2b. A second rake face 15 that is concave in one side C1 in the width direction is formed. The first spacing surface portion 16 is formed so as to incline toward the other longitudinal direction B2 as it goes from the one width direction C1 to the other width direction C2. Further, the second separation surface portion 13 of the chip 3 in the longitudinal direction B1 is formed so as to incline toward the other longitudinal direction B2 from the width direction one C1 toward the width direction other C2. Accordingly, in the tip 3, the first clearance surface 17 is formed on the first separation surface portion 16 of the other longitudinal direction B2 continuous with the first cutting edge 2a, and the second separation surface portion 13 of the longitudinal direction one B1 continuous with the second cutting blade 2b. In addition, the second flank 18 is formed.

  The chip 3 is formed of a hard material having wear resistance. For example, cemented carbide which is a sintered body mainly composed of tungsten carbide, ceramic which is a sintered body mainly composed of aluminum oxide, titanium carbide, and the like. A cermet, a diamond sintered body, or a CBN (Cubic Boron Nitride) sintered body, which is a sintered body having a main component of.

  The tip 4a of the holder 4 has a long side direction one Y1 surface portion 4b orthogonal to the axial direction X, an axial direction one X1 surface portion 4c, and a short side direction one Z1 orthogonal to the axial direction X and the long side direction Y. A mounting portion 7 is formed so as to immerse from the surface portion 4d, and a chip accommodating space is formed by the mounting portion 7. The chip accommodation space is a space in which almost the entire chip 3 is accommodated.

  Hereinafter, of the directions perpendicular to the axial direction X of the holder 4, the direction extending along the long side of the projection shape when projected onto the projection plane perpendicular to the axial line L <b> 1 is referred to as a long side direction Y. A direction perpendicular to the axial direction X and the long side direction Y of the holder 4 is referred to as a short side direction Z.

  The mounting portion 7 includes a first restraining surface portion 10, a second restraining surface portion 12, and a rear wall surface portion 19. The first constraining surface portion 10 has a surface substantially parallel to a virtual plane including the axial direction X and the long side direction Y. In order to secure the lateral clearance angle of the chip, the first constraining surface portion 10 may be inclined by 1 to 2 ° in the other short side direction Z2 as it goes to the other axial direction X2. The mounting portion 7 is formed with a constraining screw hole 21 that immerses from the first constraining surface portion 10 into the other side Z2 in the short side direction. In the restraining screw hole 21, a female thread is engraved on the inner peripheral surface portion, and the restraining screw member 5 for fixing the chip 3 is screwed together.

  The second constraining surface portion 12 and the rear wall surface portion 19 are erected adjacent to the first constraining surface portion 10 in one side Z <b> 1 in the short side direction with respect to the first constraining surface portion 10. The second constraining surface portion 12 has a surface parallel to a virtual plane including the axial direction X and the short side direction Z. The rear wall surface portion 19 is a plane including the short side direction Z, and has a plane that inclines in the other axial direction X2 from one long side direction Y1 toward the other long side direction Y2. The inclination angle of the rear wall surface portion 19 is set substantially equal to the inclination angle of the second separation surface portion 13 of the chip 3. In the intersecting region between the second constraining surface portion 12 and the rear wall surface portion 19, a retracting portion 22 that is concave in the other axial direction X2 is formed. The retracting portion 22 is a portion facing the second cutting edge 2b in the state where the chip is mounted. The retracting portion 22 causes the second constraining surface portion 12 and the rear wall surface portion 19 to contact the second cutting blade 2b undesirably and be damaged. Can be prevented.

  The rear wall surface portion 19 is formed with a pressing screw hole 23 penetrating in a direction perpendicular to the plane having the rear wall surface portion 19. In other words, the sum angle α of the inclination angle γ of the pressing screw hole 23 with respect to the width direction C and the inclination angle β of the rear wall surface portion 19 with respect to the width direction C is set to 90 degrees. One of the pressing screw holes 23 in the axial direction opens toward the second restraining surface portion 12, and the other in the axial direction opens in one of the long side directions Y <b> 1 of the holder 4. The other end in the axial direction of the pressing screw hole 23 is counterbored. A female screw is engraved on the inner peripheral surface portion of the pressing screw hole 23. Since the rear wall surface portion 19 is inclined with respect to the long side direction Y as described above, the pressing screw hole 23 is also inclined with respect to the axial direction L. The axial line of the pressing screw hole 23 is parallel to a perpendicular line from the axial line of the through hole 8 to the plane of the second separating surface portion 13 in the chip mounting state, and the axial line of the pressing screw hole 23 and the perpendicular line are only a distance d1. It is separated toward one side C1 in the width direction. The distance d1 is set to, for example, 5% or more and 40% or less of the dimension d2 along the other side B2 of the first separation surface portion 16 of the chip 3 in the longitudinal direction. The inclination angle β with respect to the width direction of the rear wall surface portion 19 is set to, for example, 10 degrees or more and 30 degrees or less.

  In the chip mounting state, the thickness direction A of the chip 3 and the short side direction Z of the holder 4 are parallel, the longitudinal direction B of the chip 3 and the axial direction X of the holder 4 are parallel, and the width direction C of the chip 3 and the holder The chip 3 is mounted on the mounting portion 7 so that the long side direction Y of 4 is parallel. Therefore, as described above, the bottom surface portion 9 of the chip 3 contacts the first restraining surface portion 10 of the holder 4 in the chip mounting state. Further, the second contact surface portion 11 of the chip 3 contacts the second restraining surface portion 12 of the holder 4. Further, the second separation surface portion 13 of the chip 3 faces the rear wall surface portion 19 of the holder 4. Therefore, the chip 3 is positioned with respect to the holder 4 with at least the bottom surface portion 9 and the second contact surface portion 11 contacting the first restraint surface portion 10 and the second restraint surface portion 12 respectively.

  The restraining screw member 5 is a screw member that presses the chip 3 toward one side A1 in the thickness direction. The restraining screw member 5 is a pressing means, and is formed with a male screw that is screwed into the female screw of the restraining screw hole 21. The pressing screw member 6 is a screw member that presses the second separation surface portion 13 of the chip 3 toward the second restraining surface portion 12. The pressing screw member 6 is formed with an external screw that is screwed into the female screw of the pressing screw hole 23. The tip of the pressing screw member 6 that is one end in the axial direction has a plane perpendicular to the axial direction.

  In the chip mounting state, the through hole 8 formed in the chip 3 and the restraining screw hole 21 formed in the mounting portion 7 are substantially coaxial. The restraining screw member 5 is inserted into the through hole 8 of the chip 3 and screwed into the restraining screw hole 21, so that almost the entire surface of the bottom surface portion 9 of the one side A <b> 1 in the thickness direction of the chip 3 is the first of the mounting portion 7. The restraining surface portion 10 is pressed and the contact state is maintained. On the other side A2 in the thickness direction of the through-hole 8, a storage space in which the head portion 5a of the restraining screw member 5 can be stored is formed, and the head portion 5a is stored in this storage space. Accordingly, the restraining screw member 5 is immersed from the other surface portion in the thickness direction of the chip 3.

  In the chip mounting state, by screwing the pressing screw member 6 into the pressing screw hole 23 of the holder 4, the tip end portion 6 a of the pressing screw hole 23 in the screwing direction is inserted into the chip 3 as shown in FIG. 1. The second abutting surface portion 13 abuts on the second spacing surface portion 13. As described above, since the distal end portion 6 a of the pressing screw hole 23 in the screwing direction has a flat surface, the entire surface of the distal end portion 6 a abuts on the second separation surface portion 13. Furthermore, the screw member 6 for pressing presses the 2nd separation surface part 13 toward the 2nd restraint surface part 12 by screwing the screw member 6 for a press. In the chip mounting state, since the second contact surface portion 11 of the chip 3 and the second restraint surface portion 12 of the holder 4 are in contact, the second contact surface portion 11 is pressed toward the second restraint surface portion 12 and pressed. The contact state is maintained. On the other side in the axial direction of the pressing screw hole 23, the pressing screw hole 23 is enlarged by the counterbore processing, so that the insertion property of the pressing screw member 6 and the operability of the pressing screw member 6 are facilitated. Formed. The length dimension of the pressing screw member 6 is set so as to be immersed from the surface portion 4b of the one Y1 in the long side direction of the holder 4. This can prevent the pressing screw member 6 from hindering the discharge of chips.

  FIG. 4 is an enlarged front view showing a part of the cutting tool 1 with the worn tip 3 attached to the holder 4. In the case where the second cutting edge 2b is mounted on the holder 4 while being protruded from the holder 4, the tip 3 is worn by cutting the work material. In this case, the second flank 18 can be re-polished to recover the cutting ability, and re-polishing can be repeated until the polishing allowance is eliminated. When the polishing allowance disappears and further re-polishing becomes impossible, the tip 3 is rotated 180 degrees around the axis of the through-hole 8 and the first cutting edge 2a is mounted in a state of protruding from the holder 4, and the first cutting edge is mounted. The work material is cut using the blade 2a. In such a case, as indicated by a virtual line in FIG. 4, the second separation surface portion 13 having the second flank 18 is retracted in the other longitudinal direction B2. Therefore, the distance between the second separation surface portion 13 and the rear wall surface portion 19 is increased. When repolishing, the polishing amount per time is, for example, about 1 mm at the maximum.

  In such a case, by further screwing the pressing screw member 6 into the pressing screw hole 23 of the holder 4, the tip end portion 6 a of the pressing screw hole 23 in the screwing direction is inserted as shown in FIG. 4. 3 abuts against the second separation surface portion 13. Therefore, even if the second spacing surface portion 13 is polished and the distance between the second spacing surface portion 13 and the rear wall surface portion 19 is changed, the second spacing surface portion 13 is pressed by the pressing screw member 6 to 2 The abutting surface portion 11 can be pressed toward the second restraining surface portion 12.

  As described above, in the cutting tool 1 according to the present embodiment, the holder 4 includes the first restraining surface portion 10, the second restraining surface portion 12, and the pressing screw member 6. In the chip mounted state, the chip 3 mounted on the holder 4 is in a chip mounted state, the bottom surface portion 9 of the thickness direction one A1 contacts the first restraining surface portion 10, and the second contact surface portion 11 of the width direction one C1 is the second restraining surface portion 12. Abut. In a state where the chip is mounted, the restraining screw member 5 is inserted into the through hole 8, is screwed into the restraining screw hole 21, and the restraining screw member 5 is screwed to move the tip toward the one direction C <b> 1 in the thickness direction. 3 is pressed against the holder 4 and fixed. In the chip mounted state, the rear wall surface portion 19 faces the second separation surface portion 13 on one side in the longitudinal direction of the chip 3, so that the pressing member 6 presses against the second separation surface portion 13 of the chip 3. The distal end portion 6a of the screw member 6 in the screwing direction comes into contact with the tip member 3 and presses the chip 3 in the screwing direction. Accordingly, the pressing screw member 6 presses the second separation surface portion 13 of the chip 3 toward the second restraining surface portion 12 in the chip mounted state. As a result, the second contact surface portion 11 of the chip 3 is pressed and fixed to the second restraining surface portion 12.

  Accordingly, the chip 3 is pressed toward the thickness direction one A1 by the restraining screw member 5, and is pressed toward the width direction one C1 by the pressing screw member 6, so that the chip 3 is firmly fixed to the holder 4. be able to. Therefore, the chip 3 can be prevented from being undesirably displaced with respect to the holder 4. In addition, since the second separation surface portion 13 on one side in the longitudinal direction of the chip 3 is pressed and fixed, the chip 3 can be reliably fixed to the holder 4 regardless of the shape of the second separation surface portion 13.

  In the present embodiment, the tip 3 is formed in a rotationally symmetric shape with respect to the axis of the through hole 8, so that the first cutting edge 2 a formed in the other longitudinal direction B 2 is worn and becomes unusable. The second cutting edge 2b formed in one longitudinal direction B1 can be used for cutting. As shown in FIG. 4, even if the second cutting edge 2b is driven into the shape by re-polishing, the second spacing surface 13 is pressed and fixed by the pressing screw member 6, so that the tip 3 is securely attached. It is fixed to the holder 4. As a result, it is possible to prevent the tip 3 from being displaced due to the use of the first cutting edge 2a and the second cutting edge 2b, and to prevent a reduction in processing accuracy.

  Further, in the present embodiment, the pressing screw member 6 is the second separation surface portion 13 of the chip 3 and presses the portion of the chip 3 near one side C1 in the width direction. Referring to FIG. 1, during cutting, the tip 3 receives a pressing force F <b> 1 from the work material toward the first cutting edge 2 a in the width direction C <b> 1 from the work material. A turning force is applied, and the first contact surface portion 20 of the chip 3 and the second restraining surface portion 12 of the holder 4 are in contact with each other by the pressing force F1. When the pressing screw member 6 is the second separation surface portion 13 of the chip 3 and presses the portion near the other width direction C2 of the chip 3, the chip 3 rotates to one circumferential direction R1 around the axis of the through hole 8. Give the turning force to make. Therefore, since the pressing force F1 at the time of cutting and the pressing force F2 applied by the pressing screw member 6 to the second separation surface portion 13 are both rotational forces that cause angular displacement in the circumferential direction R1, the second contact surface portion 11 is 2 There is a case where the constraining surface portion 12 hits one side closer to the other side C2 in the longitudinal direction. In the present embodiment, the pressing screw member 6 presses the portion close to the second restraining surface portion 12 toward the second restraining surface portion 12, and therefore rotates to the other circumferential direction R2 around the axis of the through hole 8. Gives rotational force. Therefore, the pressing force F1 at the time of cutting and the pressing force F2 that the pressing screw member 6 applies to the second separation surface portion 13 give different rotational forces to the chip 3 in the circumferential direction. As a result, the pressing forces F1 and F2 act in the direction in which the second abutting surface portion 11 abuts on the second restraining surface portion 12, so that the rotation of the tip 3 around the axis of the through hole 8 can be reliably prevented. Therefore, the chip 3 can be more firmly attached to the holder 4.

  Further, the ratio of the distance d1 to the dimension d2 along the other side B2 in the longitudinal direction of the first separation surface portion 16 of the chip 3 is set to 5% or more and 40% or less, for example. If the ratio is less than 5%, a rotational force for rotating the tip 3 in the other circumferential direction R2 cannot be applied. If the ratio is more than 40%, the second cutting edge 2b is too close to the second cutting edge 2b. May be damaged. Therefore, the ratio is preferably set to 5% or more and 40% or less.

  Furthermore, in the present embodiment, the pressing screw member 6 is perpendicular to the pressing direction, which is the screwing direction in which the pressing screw member 6 is mounted, and the plane on which the second separation surface portion 13 of the chip 3 is formed. Therefore, the total angle α of the inclination line γ of the pressing screw hole 23 with respect to the width direction C and the inclination angle β of the rear wall surface portion 19 with respect to the width direction C is set to 90 degrees. Accordingly, the pressing force F2 by the pressing screw member 6 can be efficiently applied to the second spacing surface portion 13 of the chip 3 without being reduced by the frictional force between the pressing screw member 6 and the second spacing surface portion 13. .

  Further, the inclination angle β with respect to the width direction of the rear wall surface portion 19 is set to, for example, 10 degrees or more and 30 degrees or less. If the inclination angle β is less than 10 degrees, the inclination angle γ approaches 90 degrees, so that the axial dimension of the pressing screw hole 23 becomes long, and the operation of screwing the pressing screw member 6 becomes difficult. When the inclination angle β is larger than 30 degrees, the portion pressed by the pressing screw member 6 when the flank is driven by re-grinding is too close to the second cutting blade 2b and damages the second cutting blade 2b. There is a fear. Further, since the inclination angle β corresponds to the clearance angle of the second flank 18, if it is larger than 30 degrees, the strength of the chip 3 may be lowered. Therefore, the inclination angle β is preferably set to 10 degrees or more and 30 degrees or less.

  FIG. 5 is an enlarged front view showing a part of a cutting tool 1A of another example of the present embodiment. FIG. 6 is an exploded perspective view showing a part of the cutting tool 1A of this example. FIG. 7 is an enlarged front view showing a part of the cutting tool 1A in a state where the worn tip 3 is mounted on the holder 4 of the cutting tool 1A of this example. The cutting tool 1A of this example is characterized in that a portion 6a where the pressing screw member 6 presses the chip 3 is formed in a partial spherical shape.

  The contact area where the tip end portion 6a in the axial direction of the pressing screw member 6 and the second spacing surface portion 13 abut is so-called point contact because the tip end portion 6a is formed in a partial spherical shape. Thereby, even if the angle at which the chip is pressed is slightly swung, it can be surely pressed by point contact, and a stable restraining force can be obtained. Furthermore, the area where the chip 3 and the pressing screw member 6 abut can be made smaller than when the portion pressing the chip 3 of the above-described embodiment is flat. The pressure of the pressing force acting on the chip 3 can be increased, and the chip 3 can be more firmly fixed to the holder 4.

  As indicated by phantom lines in FIG. 7, even when the second spacing surface portion 13 is retracted in the other longitudinal direction B <b> 2, the pressing screw member 6 is further screwed into the pressing screw hole 23 of the holder 4. By advancing, the distal end portion 6 a of the pressing screw hole 23 in the screwing direction can be brought into contact with the second separation surface portion 13. Even if the shape of the second spacing surface portion 13 is not flat and has a concavo-convex shape, if the distal end portion 6a is a partial spherical surface, the pressing screw member 6 can be surely brought into point contact. The second contact surface portion 11 can be pressed toward the second restraining surface portion 12 by pressing the separation surface portion 13.

  Furthermore, it is preferable to select a material so that the hardness of the pressing screw member 6 is lower than that of the chip 3. By selecting the material of the pressing screw member 6 in this way, when the pressing screw member 6 is pressed against the second separation surface portion 13, it can be deformed from a point-contacted portion and deformed into a crushed shape. Accordingly, the pressing screw member 6 and the second separation surface portion 13 can be reliably brought into contact with each other.

  The total angle α of the inclination angle γ of the pressing screw hole 23 with respect to the width direction C and the inclination angle β of the rear wall surface portion 19 with respect to the width direction C is set to 80 degrees or more and 100 degrees or less. Since the distal end portion 6a of the pressing screw member 6 is formed in a partial spherical shape, even if the axis of the second spacing surface portion 13 and the pressing screw member 6 is not 90 degrees, the pressing spacing member 13 is reliably pressed against the second spacing surface portion 13. The screw member 6 can be brought into point contact and brought into contact with each other.

  Since the total angle α is allowed to be 80 degrees or more and 100 degrees or less, the inclination angle β with respect to the width direction C of the rear wall surface portion 19 may be selected as an optimum value for cutting and the inclination angle γ may be set. The inclination angle β is set to, for example, 5 degrees or more and 10 degrees or less, and the inclination angle γ is set to, for example, 60 degrees or more and 80 degrees or less.

  In the cutting tool 1 of this example, the tip end portion 6a that presses the tip 3 of the pressing screw member 6 has a partial spherical shape. However, the cutting tool 1 is not limited to the partial spherical shape, and may have any shape that makes point contact. The distal end portion 6a of the pressing screw member 6 may be formed in a sharp protruding shape, for example, or may be conical. Even with such a configuration, the same operations and effects as the present example can be achieved.

  In the present embodiment, this is realized by using one pressing screw member 6, but the present invention is not limited to this, and a plurality of pressing screw members 6 may be used. By using the plurality of pressing screw members 6, the chip 3 can be more securely fixed to the holder 4. Moreover, when using the several screw member 6 for a press, it is preferable to form so that the formation direction of the screw groove of each screw member for a press may mutually differ. Accordingly, it is possible to prevent the plurality of pressing screw members 6 from similarly loosening due to vibration during cutting or the like.

  FIG. 8 is an enlarged front view showing a part of the cutting tool 1B according to the second embodiment of the present invention. FIG. 9 is an exploded perspective view showing a part of the cutting tool 1B, and FIG. 10 is a perspective view showing a part of the cutting tool 1B. The cutting tool 1 </ b> B of the present embodiment is characterized by the configuration of the pressing means 24.

  The pressing means 24 includes a pressing member 25 and a pressing member screw member 26. The pressing member screw member 26 is formed in a columnar shape, and includes a screw portion in which a male screw is engraved and a head portion 26a having a diameter larger than that of the screw portion. The pressing member 25 is configured to be mountable in a mounting recess 27 formed in the holder 4. The pressing member 25 has a substantially rectangular parallelepiped shape, and is formed with a pressing member hole 28 penetrating in the long side direction Y of the holder 4 when mounted on the holder 4. The pressing member hole 28 is configured such that the pressing member screw member 26 can be gently slidably displaced and rotated. A storage space in which the head portion 26a of the pressing member screw member 26 can be stored is formed in the end portion 28a of the pressing member hole 28 in the long side direction Y1. Accordingly, by inserting and slidingly displacing the pressing member screw member 26 into the pressing member hole 28, the head portion 26a of the pressing member screw member 26 is stored in the storage space, and the head portion 26a is moved in the screwing direction. Displacement is regulated. The head portion 26a is configured to be stored in the storage space, and is configured so that the head portion 26a does not protrude undesirably from the pressing member 25. Further, the pressing member 25 is in the mounted state, and the surface portion of the holder 4 in the axial direction X1 is the third constraining surface portion 30.

  The mounting recess 27 is configured such that the pressing member 25 is slidable along the long side direction Z of the holder 4, and the surface 27 a of the other side Y <b> 2 of the mounting recess 27 is pressed through the other side Y <b> 2 in the long side direction. A member screw hole 29 is formed. The pressing member screw hole 29 is a hole in which a female screw is engraved on the inner peripheral surface portion, and the pressing member screw member 26 can be screwed along the long side direction Y. In the mounted state, the pressing member hole 28 is coaxial with the pressing member screw hole 29 formed in the mounting recess 27. The pressing member 25 is slid along the long side direction Y with respect to the holder 4 by screwing the pressing member screw member 26 into the pressing member hole 28 and the pressing member screw hole 29 of the pressing member 25. be able to.

  As shown in FIG. 8, in the chip mounted state, the chip 3 to be mounted on the holder 4 has the bottom surface portion 9 in the thickness direction one A1 in contact with the first restraining surface portion 10 and the second contact surface portion in the width direction one C1. 11 abuts on the second restraining surface portion 12. In the chip mounting state, the third constraining surface portion 30 faces the second separation surface portion 13 in the longitudinal direction of the chip 3, and the pressing member screw member 26 is screwed, whereby the pressing member 25 is moved in the other side Y2. The third constraining surface portion 30 abuts on the second separation surface portion 13 of the chip 3 and presses the chip 3 in a direction perpendicular to the plane of the second separation surface portion 13. Accordingly, the pressing member 25 presses the second separation surface portion 13 of the chip 3 toward the second restraining surface portion 12 in the chip mounted state. As a result, the second contact surface portion 11 of the chip 3 is pressed and fixed to the second restraining surface portion 12.

  FIG. 11 is an enlarged front view showing a part of the cutting tool 1 </ b> B in a state where the worn tip 3 is mounted on the holder 4. As shown by phantom lines in FIG. 11, even when the second separation surface portion 13 is retracted in the other longitudinal direction B <b> 2, the pressing member screw member 26 is inserted into the pressing member screw hole 29 of the holder 4. By further screwing, the third restraining surface portion 30 of the pressing member 25 can be brought into contact with the second separation surface portion 13. Therefore, the second contact surface portion 11 can be pressed toward the second restraint surface portion 12.

  By using such a pressing member 25, even if the pressing member 25 is damaged by contact with the chip 3, the present embodiment can be continued by replacing the pressing member 25 with a new pressing member 25. The form of pressing means 24 can be realized.

  Moreover, since each hole 8, 21, 28, 29 is formed in the direction perpendicular | vertical with respect to each surface part, it is easy to process and can form each hole accurately. Thereby, the cost for realizing the cutting tool 1B of the present embodiment can be reduced.

  Moreover, in this Embodiment, since the press member 25 and the screw member 26 for press members should just be a dimension smaller than the dimension of the long side direction Y of a holder, it can be implement | achieved in the big shape with respect to the chip | tip 3. FIG. Therefore, the operator can easily work on the pressing member 25 and the pressing member screw member 26.

  In each of the embodiments described above, the pressing means 24 is realized by the pressing screw member 6 or the pressing member 25. However, the pressing means 24 is not limited to this, and comes into contact with the second separation surface portion 13 and the second contact surface portion. Any configuration may be used as long as 11 is pressed against the second restraining surface portion 12. The pressing unit 24 may have a configuration in which a pressing force generating unit such as a spring is provided on the rear wall surface portion 19 and the pressing force is applied to the second separation surface portion 13.

  The pressing means 24 may be realized by a screw member that can be screwed and screwed along the short side direction Z of the holder 4. The pressing member 24 can be realized by configuring the outer peripheral surface portion or the distal end portion of the side screw member to press the second separation surface portion 13 by screwing the screw member toward the other side Z2 in the short side direction. it can. By providing such a side screw member, the side screw member can be operated from one side Z <b> 1 in the short side direction of the holder 4 in the same manner as the restraining screw member 5 of the chip 3. Therefore, the present invention can be realized even when there is only a working space Z1 on the short side direction of the cutting tool.

It is a front view which expands and shows a part of cutting tool 1 of a 1st embodiment of the present invention. 2 is an exploded perspective view showing a part of the cutting tool 1. FIG. 1 is a perspective view showing a part of a cutting tool 1. FIG. It is a front view which expands and shows a part of cutting tool 1 in the state where the worn tip 3 is mounted on the holder 4. It is a front view which expands and shows a part of cutting tool 1A of the other example of this Embodiment. It is a disassembled perspective view which shows a part of cutting tool 1A of this example. It is a front view which expands and shows a part of cutting tool 1A of the state which mounted | wore the chip | tip 3 which was abraded to the holder 4 of the cutting tool 1A of this example. It is a front view which expands and shows a part of cutting tool 1B of the 2nd Embodiment of this invention. It is a disassembled perspective view which shows a part of cutting tool 1B. It is a perspective view which shows a part of cutting tool 1B. It is a front view which expands and shows a part of cutting tool 1B in the state which mounted | wore the holder | tip 3 with which the wear | wear 4 was mounted | worn.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cutting tool 2 Cutting blade 3 Tip 4 Holder 5 Restraining screw member 6 Pressing screw member 8 Through hole 9 Bottom face part 10 First restraining surface part 11 Second contact surface part 12 Second restraining surface part 13 Second separation surface part 19 Rear wall surface 19 Part 21 Restraint screw hole 23 Press screw hole 24 Press means 25 Press member 26 Press member screw member 28 Press member hole 29 Press member screw hole 30 Third restraint surface part

Claims (8)

A substantially rectangular plate-shaped chip having a cutting edge is detachable, and a holder to which a chip can be mounted in a chip mounting state in which the cutting edge of the chip protrudes from the outer peripheral surface part,
A restraining screw that is a first constraining surface portion that contacts one surface portion in the thickness direction of the chip in a state where the chip is mounted, and that opens to face the through hole that is formed in the chip and penetrates in the thickness direction of the chip, and is inserted into the through hole. A first restraining surface portion in which a restraining screw hole into which the member is screwed is formed;
A second constraining surface part in contact with one surface part in the width direction of the chip in the chip mounting state;
A holder comprising: a pressing unit that presses one longitudinal surface portion of the chip toward the second constraining surface portion when the chip is mounted.   2. The holder according to claim 1, wherein the pressing means presses a portion on one side in the longitudinal direction of the chip and closer to one side in the width direction of the chip.   The holder according to claim 1 or 2, wherein the pressing means is perpendicular to a pressing direction in which the pressing means is pressed and a plane forming one surface portion in the longitudinal direction of the chip. In the mounted state of the chip, further includes a rear wall surface portion facing one surface portion in the longitudinal direction of the chip,
The pressing means includes a pressing screw member for pressing the chip with the chip mounted.
The screwing hole for pressing which the screwing member for screwing is formed in the rear wall part so as to face the second restraining surface part is formed. Holder.   The holder according to claim 4, wherein the pressing screw member is formed so that a portion for pressing the tip is formed in a partial spherical shape. The pressing means is a pressing member in which a hole for a pressing member penetrating in the width direction of the chip is formed in the chip mounting state, and a pressing member in which a third restraining surface portion facing one surface portion in the longitudinal direction of the chip is formed. When,
A screw member for a pressing member that is inserted through the hole for the pressing member and can be screwed along the width direction of the chip,
The holder according to any one of claims 1 to 3, wherein a screw hole for a pressing member into which the screw member for the pressing member is screwed is formed.   It is a chip | tip mounted | worn with the holder as described in any one of Claims 1-6, Comprising: About the axis line of a through-hole, it forms in a rotationally symmetrical shape. A holder according to any one of claims 1 to 6;
A cutting tool comprising the tip according to claim 7.

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