JP4782450B2 - Inner diameter holder and cutting tool - Google Patents

Description

  The present invention relates to an inner diameter processing holder and a cutting tool used for inner diameter processing such as grooving in cutting of a metal material or the like.

  In general, in cutting of metal materials and the like, as an inner diameter processing holder used for inner diameter processing such as grooving and a cutting tool using the same, there is a structure in which the cutting edge of the throw-away tip protrudes from the tip of the holder. Are known. As such a cutting tool, Patent Literature 1 describes a clamp bit that can cut a groove on an inner peripheral surface of a workpiece.

  FIG. 5 is a front view showing a conventional cutting tool for inner diameter processing as described in Patent Document 1. As shown in FIG. As shown in FIG. 5, the cutting tool 40 includes a holder 47 and a throw-away tip 10, and the holder 47 has a substantially rod-shaped shank portion 41 and a lower jaw portion 42 protruding from one end of the shank portion 41. A tip mounting portion 43 disposed so as to open toward the outer peripheral direction at the distal end portion of the lower jaw portion 42, and an upper jaw portion formed integrally with the lower jaw portion 42 via a slit 44 above the lower jaw portion 42. 45 and a fixing bolt 46 for tightening the upper jaw 45.

  Furthermore, a flat cut portion 48 is formed at the distal end portion of the lower jaw portion 42 and the upper jaw portion 45 on the other side without the tip mounting portion 43 and is cut obliquely rearward from the distal end surface of the lower jaw portion 42 and the upper jaw portion 45. ing. Then, the chip 10 is placed on the chip mounting part 43 formed on the lower jaw part 42 so that the cutting edge protrudes in the outer circumferential direction, and then the upper surface of the chip 10 is pressed with the upper jaw part 45 and tightened with the fixing bolt 46. Then, the chip 10 is fixed. The cutting tool 40 is inserted into a cylindrical workpiece made of a metal material or the like, and then the cutting edge of the chip 10 is applied to the inner wall 50 of the workpiece to be used for inner diameter processing such as grooving.

  On the other hand, when the inner diameter of the work material and the tip diameter of the cutting tool are close to each other, that is, when the clearance between the holder 47 and the inner wall 50 is small, in other words, when positioning the cutting tool, When the cutting tool is inserted into the inner diameter of the work material or when the cutting tool is pulled out from the work material, there arises a problem that the holder 47 and the inner wall 50 are likely to interfere with each other. In other words, since the range in which the holder 47 and the inner wall 50 of the work material do not interfere with each other is narrow, alignment is difficult.

  Therefore, the holder 47 is formed with a flat cut portion 48 at the distal ends of the lower jaw portion 42 and the upper jaw portion 45 on the other side without the tip mounting portion 43. As a result, the clearance between the distal ends of the lower jaw part 42 and the upper jaw part 45 on the other side and the inner wall 50 of the work material is widened. As a result, the movable range of the holder is widened. Positioning becomes easy. However, by forming the flat cut portion 48, the thickness of the head portion 42 of the holder 47 is reduced, and the rigidity of the holder 47 itself is lowered.

Registered Utility Model No. 3034181

  An object of the present invention is to provide an inner diameter machining holder and a cutting tool which are easy to align when inserted into a work material and have excellent holder rigidity.

  As a result of intensive studies to solve the above problems, the present inventor has found that the other side without the tip mounting portion at the tip portion of the head portion is inclined toward the one side as it goes from the shank side to the tip side. Since it is composed of a curved surface part, the clearance between the inner wall of the work material and the holder is secured, and the effect of facilitating alignment when inserting into the work material, while also maintaining the tip of the holder As a result of increasing the wall thickness, a new finding has been found that an inner diameter machining holder can be obtained in which the rigidity of the head portion is not reduced by forming a flat cut portion, and the present invention has been completed.

That is, the inner diameter processing holder and the cutting tool in the present invention have the following configurations.
(1) A chip provided with a substantially rod-shaped shank portion and a head portion protruding from one end of the shank portion, the head portion being disposed so as to open to the tip side and one side of the head portion. An inner diameter processing holder provided with an attachment portion, wherein the tip attachment portion is formed on one side in a width direction at a tip portion of the head portion, and a curved surface portion convex to the side is formed on the other side. An inner diameter machining holder formed, wherein the convex curved surface portion is inclined toward the one side as it goes from the shank side to the tip side.
(2) The head portion is formed from the front end side to the rear end side of the head portion, and an upper jaw portion and a lower jaw formed integrally with the shank portion by a slit that vertically divides the front end side of the head portion. In the tip mounting portion, an upper clamp surface for pressing and fixing from above the throw-away tip is formed on the upper jaw portion and a lower surface serving as a placement surface for the throw-away tip. The inner diameter processing holder according to (1), wherein a clamp surface is formed on the lower jaw.
(3) The inner diameter processing holder according to (2), wherein the end of the slit is an arcuate curved surface having a diameter larger than the width of the slit.
(4) A throw-away tip is disposed on the tip mounting portion of the inner diameter processing holder according to any one of (1) to (3) so that a cutting blade projects toward at least one of the front side and one side. Cutting tool characterized by wearing.

  According to the above (1), since the other side without the tip mounting portion at the tip portion of the head portion is composed of a convex curved portion inclined toward the one side as it goes from the shank side to the tip side, While securing the clearance between the inner wall of the work material and the holder and maintaining the effect of easy alignment when inserted into the work material, the thickness of the holder tip (head part) is increased. As a result, an inner diameter machining holder having high rigidity of the holder itself can be obtained.

  According to the above (2) and (3), even when the holder configuration is such that the throw-away tip is sandwiched and fixed between the upper jaw portion and the lower jaw portion, it is easy to align when inserted into the work material. In addition, a highly rigid inner diameter machining holder can be obtained. According to the above (4), it is possible to obtain a cutting tool for inner diameter machining that is easy to align when inserted into a work material and that is excellent in the strength of the lower jaw of the holder.

  Hereinafter, an embodiment of an inner diameter processing holder and a cutting tool according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a cutting tool in which a throwaway tip is mounted on the inner diameter processing holder of this embodiment, and FIG. 2A is a plan view showing the cutting tool of this embodiment. (B) is the left side view, FIG. 2 (c) is the right side view, FIG. 3 is a front view showing the cutting tool of this embodiment, and FIG. 4 is this embodiment. It is the schematic for demonstrating the convex-shaped curved surface part concerning.

  As shown in FIGS. 1 to 4, the cutting tool 20 includes an inner diameter processing holder 1 and a throw-away tip (hereinafter abbreviated as a tip) 10. The inner diameter processing holder 1 is roughly divided into a substantially rod-shaped shank portion 2 and a head portion 3 protruding from one end of the shank portion 2. Further, the head portion 3 is formed from the front end side to the rear end side of the head portion 3 and is formed integrally with the shank portion 2 by a slit 5 that divides the front end side of the head portion 3 vertically. In the tip mounting portion 4, an upper clamp surface for pressing and fixing from above the tip 10 is formed on the upper jaw portion 6, and a lower surface serving as a placement surface for the tip 10. A clamping surface is formed on the lower jaw part 9, and a fixing bolt 7 is provided for holding the tip 10 by pressing down the upper jaw part 6 toward the lower jaw part 9. Here, the shank portion 2 may be substantially rod-shaped, and any shape can be adopted as long as it can be used as a holder for inner diameter processing.

  And the other side without the chip attachment part 4 in the front-end | tip part of the head part 3 is comprised by the curved surface part 21 which swelled convexly. As a result, the clearance between the inner wall of the work material and the holder is secured, and while maintaining the effect of easy alignment when inserted into the work material, the thickness of the holder tip is increased. As a result, an inner diameter processing holder having high rigidity of the holder itself can be obtained. In the present embodiment, the curved surface portion 21 is composed of a curved surface portion 21a formed on the lower jaw portion 9 and a curved surface portion 21b formed on the upper jaw portion 6, and the curved surface portions 21a and 21b are formed as continuous convex curved surfaces. Is done.

  Specifically, as shown in FIGS. 3 and 4, the head portion 3 is formed to protrude from one end of the shank portion 2 along the central axis L of the shank portion 2. In the convex curved surface portion 21, the center C having a circular arc shape with respect to the central axis L of the shank portion 2 is sequentially displaced from the shank portion 2 side toward the tip end side toward the tip mounting portion 4 side. It is preferable that the displacement β is displaced so that the ratio of the diameter α of the shank portion 2 is α: β = 10: 1-2.

  Further, the curvature radius R2 of the arcuate cross section of the convex curved surface portion 21 is formed as a curved surface larger than the curvature radius R1 of the head portion 3. Specifically, as shown in FIG. 4, the ratio of the curvature radius R1 of the head portion 3 to the curvature radius R2 of the arc-shaped cross section of the convex curved surface portion 21 is 1: 1.1 to 2.5, preferably 1 : It is good that it is 1.1-1.5. Thereby, the movable range of the holder 2 can be maintained while increasing the rigidity of the head portion 3, particularly the lower jaw portion 9, and alignment when inserting into the work material can be easily performed.

  The chip attachment portion 4 is disposed at the tip portion of the head portion 3 so as to open toward the outer peripheral direction. Thereby, the cutting tool 20 which fixed the chip | tip 10 to the chip | tip attachment part 4 can be used suitably for internal diameter processing, such as grooving of a metal material. Note that the present invention is not limited to the tip mounting portion 4 disposed so as to open toward the outer peripheral direction, and may be in front of or at one side of the tip portion of the head portion 3 depending on processing conditions. For example, it may be disposed so as to protrude forward from the front end surface of the head portion 3.

  The slit 5 is formed so as to be inclined upward from the front end surface including the chip attachment portion 4 toward the rear end portion. The end 8 of the slit 5 is formed by an arcuate curved surface having a diameter larger than the width of the slit. Thereby, the stress concentration to the specific location of the slit end when the chip is repeatedly attached and detached can be alleviated and the occurrence of cracks from the location can be suppressed. In addition, this invention is not limited to the slit 5 formed in the upward inclination, and if it is a shape which functions as a slit of a holder, it will not be specifically limited. For example, the slit may be formed so as to be parallel to the central axis L of the shank portion from the front end surface including the chip attachment portion 4 toward the rear end portion.

  In the present embodiment, the tip 10 is sandwiched and fixed by the upper jaw 6 and the lower jaw 9 provided through the slit 5, but means for fixing the tip 10 is limited to this. Instead, various known chip fixing means that can fix the chip 10 to the chip mounting portion can be used. For example, a fixing bolt is used as the chip fixing means, and the chip 10 is attached to the chip mounting portion 4 with this fixing bolt. The structure to fix may be sufficient.

  The fixing bolt 7 is inserted into a through hole (not shown) formed substantially at the center of the upper jaw portion 6 and screwed into a screw hole (not shown) formed in the head portion 3. As a result, the upper jaw portion 6 having an upper clamp surface that presses the upper surface of the chip 10 can be fastened with the fixing bolt 7, and the chip 10 can be pressed and fixed to the chip mounting portion 4.

  Then, the chip 10 is placed on the lower clamp surface of the chip mounting portion 4 in the inner diameter processing holder 1 having the above-described configuration so that the cutting edge protrudes in the outer peripheral direction, and the fixing bolt 7 is tightened to tighten the chip 10. The cutting tool 20 is configured by pressing the upper surface with the upper clamp surface of the upper jaw portion 6 and fixing the tip 10. The cutting tool 20 is inserted into a work material such as a metal material, and then the cutting edge of the chip 10 is applied to the inner wall 50 of the work material and used for inner diameter processing such as grooving. At this time, since the tip portion of the head portion 3 (the upper jaw portion 6 and the lower jaw portion 9) is formed with curved surface portions 21 and 22 that are convex on the other side without the tip mounting portion 4, respectively. The tip of the head portion 3 (upper jaw portion 6 and lower jaw portion 9) on the other side is less likely to interfere with the inner wall 50 of the work material, and can easily be aligned when inserted into the work material. 3 is excellent in rigidity, and can be used for inner diameter processing for a long time.

It is a perspective view which shows one Embodiment of the cutting tool which mounted | wore the throw away tip in the holder for internal diameter processing in this invention. (A) is a top view which shows one Embodiment of a cutting tool, (b) is the left view, (c) is the right view. It is a front view showing one embodiment of a cutting tool. It is the schematic for demonstrating the convex-shaped curved surface part concerning one Embodiment. It is a front view which shows the conventional cutting tool for internal diameter processing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner diameter processing holder 2 Shank part 3 Head part 4 Tip attachment part 5 Slit 6 Upper jaw part 7 Fixing bolt 8 Hole 9 Lower jaw part 10 Throw away tip 20 Cutting tool 21, 21, 21a, 21b Convex curved surface part 50 Work material inner wall

Claims (4)

A substantially rod-shaped shank portion, and a head portion protruding from one end of the shank portion;
The head portion is an inner diameter processing holder provided with a tip mounting portion disposed so as to open to the tip side and one side of the head portion,
The tip mounting portion is formed on one side in the width direction at the tip of the head portion, and on the other side, a convex curved surface portion is formed on the side, and the convex curved surface portion is on the shank side. An inner diameter processing holder which is inclined toward the one side as it goes from the tip to the tip.   The head portion is formed from the front end side to the rear end side of the head portion, and is divided into an upper jaw portion and a lower jaw portion formed integrally with the shank portion by a slit that divides the front end side of the head portion into upper and lower portions. In the tip mounting portion, an upper clamp surface for pressing and fixing from above the throw-away tip is formed on the upper jaw portion, and a lower clamp surface serving as a mounting surface for the throw-away tip is formed in the tip attaching portion. The inner diameter processing holder according to claim 1, wherein the holder is formed on the lower jaw.   3. The inner diameter processing holder according to claim 2, wherein the end of the slit is an arcuate curved surface having a diameter larger than the width of the slit. A throwaway tip is mounted on the tip mounting portion in the inner diameter processing holder according to any one of claims 1 to 3 so that a cutting blade projects toward at least one of the front side and one side. Cutting tool to do.

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