JP2008296348A - Rotary cutting tool and reference position detecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary cutting tool excellent in practicality, which detects a reference position without the contact of a tool tip with a contact position detector, and also detects the reference position inexpensively and accurately using the contact position detector even for a rotary cutting tool having an extremely small diameter, and also to provide a reference position detecting method. <P>SOLUTION: The rotary cutting tool has a blade part 1 on a leading end side, and a shank part 2 on a base end side. A surface 4 orthogonal to the rotating axis of the tool is provided either on the shank part 2 or on a protruding part protrusively provided on the shank part 2 where the blade part 1 is to be set. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotary cutting tool and a reference position detection method.

  As shown in FIG. 1, a rotary cutting tool B such as an end mill or a drill is attached to a spindle of a machining center (rotary machine tool) via a holder A, and a workpiece C placed on a table surface F by this tool B. In general, when a cutting process is performed, a machining program is created based on the position of the upper surface of the workpiece C to perform the cutting process. For this reason, it is important to accurately grasp the relative distance between the upper surface position of the workpiece C and the tip position of the tool B attached to the spindle and reflect it in the machining program when performing high-precision cutting. Although FIG. 1 shows a vertical machining center, the same applies to a horizontal machining center.

  Specifically, the tool axis direction coordinates when the tip of the tool B (the non-rotating stopped tool B) and the upper surface of the workpiece C contact and coincide with each other are set as the reference position (zero point). Yes. Here, if the tip of the tool B is simply brought into contact with the upper surface of the workpiece C, there is a high possibility that the cutting edge provided at the tip of the tool will be chipped, or that the small-diameter tool B will be broken. Therefore, a dedicated contact-type position detector D whose dimensions (height from the bottom surface to the top surface) are known in advance is installed on the upper surface of the work C, and the known dimensions of the contact-type position detector D are subtracted. The upper surface position (reference position) is calculated.

  As the contact-type position detector D, for example, as disclosed in Patent Document 1, the contact-type position detector D has a pressure-sensitive portion E provided so as to be able to project and retract with respect to the detector main body, and the pressure-sensitive portion E faces the tool side. The tool is configured to be biased by an appropriate biasing member, and when the pressure sensitive part E is immersed against the biasing force of the biasing member, the tool is detected by detecting the immersion of the pressure sensitive part E In general, a configuration in which a pressure is detected and notified by a lamp or the like is generally used.

  Further, not a contact type position detector as described above, but a non-contact type position detection apparatus using a laser or a CCD camera as disclosed in Patent Document 2, for example, is also used. Note that this non-contact type position detecting device is incorporated in a machining center.

  However, the non-contact position detector is expensive, has a limited use environment, and is inferior in versatility such as a limited detection target diameter.

  Further, the non-contact position detector, for example, performs position detection in a state where cutting oil is attached to the tool tip that is the tip position detection target (which is not uncommon in a general machining environment). In this respect, if it is a contact type position detector, even if cutting oil adheres, the tool tip position accuracy is not greatly affected.

  In general, because the structure is simple, inexpensive and excellent in environmental resistance, there is no breakage of the tool at the time of position detection, there is no damage to the cutting edge, or there is no limit to the detection target as long as it is as small as possible. Currently, contact type position detectors are frequently used.

JP 2006-62061 A JP 2001-328049 A

  By the way, when using a contact-type position detector, especially when using a very small diameter tool with an outer diameter of the blade portion of 0.1 mm or less, tool breakage and chipping are likely to occur during contact with the contact-type position detector. There is a high possibility of losing the function of the tool before.

  The present invention has been made in view of the above-described situation, and a right-angle surface or an inclined surface provided on a shank portion other than the blade portion and the outer periphery of the tool without bringing the tool tip into contact with the contact-type position detector. It is possible to detect the reference position by pressing the pressure sensitive part of the contact type position detector with the crossed ridge line with the surface. The present invention provides a rotary cutting tool and a reference position detection method that are extremely practical and capable of detecting a reference position.

  The gist of the present invention will be described with reference to the accompanying drawings.

  A rotary cutting tool having a blade portion 1 on the distal end side and a shank portion 2 on the proximal end side, wherein the projection portion provided with the blade portion 1 protruding from the shank portion 2 or the shank portion 2 is provided. The rotary cutting tool is characterized in that a surface 4 perpendicular to the rotational axis of the tool is provided.

  Moreover, it is a rotary cutting tool which has the blade part 1 in the front end side, and has the shank part 2 in the base end side, Comprising: The protrusion by which the said blade part 1 protrudingly provided by the said shank part 2 or this shank part 2 is provided Is provided with an inclined surface 5 which is inclined downward toward the tool base end side toward the tool center side.

  Further, in the rotary cutting tool according to any one of claims 1 and 2, the perpendicular surface 4 or the inclined surface 5 is positioned radially outside the blade portion 1 when viewed from the tip of the tool. It concerns on the rotary cutting tool characterized by these.

  Further, in the rotary cutting tool according to any one of claims 1 to 3, the right-angle surface 4 or the inclined surface 5 is provided at a position near the outer periphery of the tip surface of the shank portion 2 or the protrusion. The present invention relates to a rotary cutting tool.

  The rotary cutting tool according to any one of claims 1 to 4, wherein the outer diameter of the blade portion is 0.1 mm or less.

  Further, a contact-type position having a pressure-sensitive portion 7 placed on the reference surface and capable of detecting pressure by a rotary cutting tool on the reference surface, with the workpiece surface 19 or a surface whose relative distance to the workpiece surface 19 is known as a reference surface. A reference for detecting a reference position by measuring a relative distance between the tip of the rotary cutting tool according to any one of claims 1 to 5 and the reference surface, which is attached to a spindle of the rotary machine tool using a detector 6. In the position detection method, the pressure-sensitive portion 7 includes a concave portion 10 that allows the blade portion 1 to escape, and an abutting portion 11 on which an intersecting ridge line between the perpendicular surface 4 or the inclined surface 5 and the outer peripheral surface of the tool abuts. And a reference position detecting method, wherein the reference position is detected by pressing the contact portion 11 of the jig 9 with the perpendicular surface 4 or the intersecting ridge line. Is.

  Further, a contact-type position having a pressure-sensitive portion 7 placed on the reference surface and capable of detecting pressure by a rotary cutting tool on the reference surface, with the workpiece surface 19 or a surface whose relative distance to the workpiece surface 19 is known as a reference surface. A reference for detecting a reference position by measuring a relative distance between the tip of the rotary cutting tool according to any one of claims 1 to 5 and the reference surface, which is attached to a spindle of the rotary machine tool using a detector 6. A reference position detection method, wherein the reference position is detected by directly pressing the pressure-sensitive part 7 with a cross ridge line between the perpendicular surface 4 or the inclined surface 5 and the outer peripheral surface of the tool. It is related to.

  Since the present invention is configured as described above, the reference position can be detected without bringing the tip of the tool into contact with the contact-type position detector, and the contact-type position detector can be used even for an extremely small diameter rotary cutting tool. It is a rotary cutting tool and a reference position detection method with excellent practicality that enables precise reference position detection at low cost.

  An embodiment of the present invention which is considered to be suitable will be briefly described with reference to the drawings showing the operation of the present invention.

  When detecting the reference position when machining with the tool attached to the spindle of the machining center, the pressure-sensitive portion 7 of the contact-type position detector 6 is a perpendicular surface 4 provided on the shank portion 2 or the like other than the blade portion or inclined. It is possible to perform detection by directly or indirectly pressing the intersecting ridge line between the surface 5 and the outer peripheral surface of the tool. Therefore, the tool tip is not brought into contact with the contact-type position detector 6, that is, the tool tip is moved. It is possible to detect the reference position without damaging it, and it is possible to detect the reference position with high accuracy and low cost even with a very small diameter rotary cutting tool that is easily broken.

  Specific embodiments of the present invention will be described with reference to the drawings.

  The present embodiment is a rotary cutting tool having a blade portion 1 on the distal end side and a shank portion 2 on the proximal end side. The shank portion 2 has a diameter larger than that of the blade portion 1 toward the tool center side. An inclined surface 5 that is inclined downward toward the tool base end side is provided, and an edge 8 perpendicular to the rotation axis of the tool is provided at an intersecting ridge line between the inclined surface 5 and the outer peripheral surface of the tool.

  Each part will be specifically described.

  The blade portion 1 is connected to a shank portion 2 having a diameter larger than that of the blade portion 1 held via a chuck cylinder 15 on a tool holder 14 attached to the spindle of the machining center. The step portion (tip surface of the shank portion 2) of the continuous portion is set on the shoulder portion 3, and the inclined surface 5 is provided on the shoulder portion 3. In addition, as a tool, the solid tool with which the blade part 1 and the shank part 2 were integrated may be employ | adopted, and the tool which joined the blade part 1 and the shank part 2 by brazing etc. may be employ | adopted. Further, the blade portion 1 is provided on a plurality of taper portions, cylindrical portions, or the like protruding from the shank portion 2, and an inclined surface 5 is provided on the protrusion portions (tip surfaces thereof) such as the taper portions or the cylindrical portions. Alternatively, a right-angle surface 4 described later may be formed.

  The inclined surface 5 provided on the shoulder portion 3 is provided on the outer side in the radial direction of the blade portion 1 when viewed from the tip of the tool so that the inclined surface 5 can come into contact with the pressure-sensitive portion 7 of a general contact-type position detector 6.

  Specifically, as shown in FIG. 2, the inclined surface 5 is substantially mortar so as to incline downward from the outermost peripheral position of the shoulder portion 3 toward the root position of the blade portion 1 over the entire front end surface of the shoulder portion 3. It is provided in the shape. The inclined surface 5 is formed by grinding the shoulder portion 3 with an appropriate grindstone (diameter 70 mm to 200 mm), and has an R shape resulting from the radius of the grindstone.

  Further, an edge 8 perpendicular to the tool axis is provided on the intersecting ridge line between the inclined surface 5 and the outer peripheral surface of the tool (the outer peripheral surface 16 of the shank portion 2). The outer peripheral surface of the tool that forms the intersecting ridge line with the inclined surface 5 is not limited to the outer peripheral surface 16 of the shank portion 2, and as shown in FIG. May be used as the outer peripheral surface of the tapered portion 17.

  That is, the inclined surface 5 forms an edge 8 perpendicular to the intersecting ridge line with the outer peripheral surface 16 of the shank portion 2, and the perpendicular edge 8 can be brought into contact with the pressure-sensitive portion 7 of the contact-type position detector 6. As long as it is a configuration that is located at the most distal end side in the shoulder portion 3, any shape may be employed, such as a configuration in which the inclined surface 5 is provided in a part rather than the entire distal end surface of the shoulder portion 3.

  In addition, a part (a right-angled edge 8) in which the length from the intersecting ridge line to the tool tip is measured in advance is provided in a part of the intersecting ridge line, and a marking 18 is provided on the shank portion 2 to make it easy to distinguish the part. ing. In the present embodiment, the above-described configuration is used to simplify the description. However, if a portion where the distance from the tool tip to the intersecting ridge line is known as a part of the intersecting ridge line is not necessarily specified. It is not necessary to provide the right-angled edge 8 (It is good also as a structure which presses the postscript pressure-sensitive part 7 using the part which is not right-angled with respect to a tool axis center among the cross ridgelines of the said inclined surface 5 and a tool outer peripheral surface.) .

  Therefore, the reference position of the tool can be determined without contacting the tip of the tool with the contact type position detector 6 by pressing the pressure sensitive part 7 of the contact type position detector 6 with the intersecting ridge line (right edge 8). It is possible to detect the reference position by the contact-type position detector 6 easily and satisfactorily even with a rotary cutting tool that has a blade outer diameter (tool diameter) of 0.1 mm or less and is easily broken. Become. In addition, even with a tool with a blade outer diameter (tool diameter) exceeding 0.1 mm, the protrusion having the blade is elongated in the tool axis direction (high aspect ratio) and can be easily broken. The reference position detection by the contact-type position detector 6 can be easily and satisfactorily performed even with respect to a rotary cutting tool having a low strength of the provided cutting edge and easily causing chipping. In the case where a tapered portion or the like is provided at the tip of the shank portion as in the tool B in FIG. 1 and there is no inclined surface 5 or a right-angled surface 4 described later, the pressure-sensitive portion 7 is pressed by this tapered portion to provide a precise reference. Position detection cannot be performed.

  Specifically, the reference position is detected using a jig 9 as shown in FIG. This jig 9 is a substantially U-shaped body in plan view in which a concave portion 10 for escaping the blade portion 1 is provided, and has a triangular prism-like contact that contacts the crossed ridge line (right-angled edge 8) at one point on the upper surface. A part 11 is provided. The height of the jig 9 is set to at least the length from the intersecting ridge line (perpendicular edge 8) to the tool tip. Moreover, it is not limited to a substantially U-shaped body in cross section, and may be a cylindrical shape or a rectangular tube shape.

  Therefore, a general commercially available contact type position detector 6 is placed on the workpiece surface 19, a jig 9 is placed on the pressure sensitive part 7 of the contact type position detector 6, and the blade part 1 is positioned in the recess 10. Then, after aligning the edge 8 perpendicular to the intersecting ridgeline between the inclined surface 5 and the outer peripheral surface 16 so as to be in contact with the tip ridgeline of the contact portion 11, the tool is lowered (FIG. 2 (a) → (B)) It becomes possible to press the pressure-sensitive portion 7 through the jig 9 by the right-angled edge 8 without contacting the tool tip.

  Then, the height of the contact-type position detector 6 and the height of the jig 9 are subtracted from the position of the perpendicular edge 8 obtained by sensing that the pressure-sensitive portion 7 is pressed, and the tool tip It is possible to calculate the reference position (workpiece surface position) by adding a known length from the right edge to the right edge 8.

  Further, when there is another surface (for example, the table surface F in FIG. 1) whose relative distance to the workpiece surface 19 is known, the contact-type position detector 6 is placed on the surface, and the position is the same as described above. It is possible to calculate the reference position (work surface position) by detecting and adding or subtracting the relative distance from the work surface 19, for example, placing the contact position detector 6 with a small work surface area. It is effective when it is difficult.

  In addition, when the contact type position detector 6 'is configured to be pressed directly by the right edge 8, that is, when the right edge 8 and the pressure sensitive part 7' are brought into contact with each other, the tool tip (blade 1) is detected by the detector. A contact-type position detector 6 ′ having a configuration that does not interfere with the main body 20 or the like may be employed, and the reference position detection may be performed by directly pressing the pressure-sensitive portion 7 ′ with a right-angled edge 8. For example, as shown in FIG. 5, the pressure-sensitive part 7 ′ has a structure in which the jig 9 and the pressure-sensitive part 7 are integrated, or the pressure-sensitive part 7 ′ has an upper surface as shown in FIG. A similar abutting portion 11 ′ is provided, and the projection amount of the detector body 20 with respect to the pressure-sensitive portion 7 ′ is less than the distance from the right edge 8 to the side surface of the blade portion 1 in plan view so that the blade portion 1 does not contact. It is good also as a structure made into protrusion amount. Further, although not shown, the pressure-sensitive portion 7 ′ is detected as a long-axis cylinder longer than the length from the right edge 8 to the tool tip (a cylinder or a square tube may be used, and a contact portion 11 ′ is provided at the tip). It is also possible to have a configuration that protrudes from the center of the vessel body 20, and in this case, in particular, it becomes possible to press the vicinity of the center of the pressure-sensitive portion 7 ′ with a tool as compared with the configurations of FIGS. Pressing can be detected.

  Further, when a predetermined range (a range in contact with the pressure-sensitive portion 7 ′ or the entire circumference of the tool) can be formed on the edge 8 perpendicular to the tool axis with a very high accuracy instead of a small part of the intersecting ridge line, the pressure-sensitive portion 7 It is not necessary to provide the protrusion 11 on the '.

  Further, in the present embodiment, the inclined surface 5 is formed on the shoulder 3, but the surface 4 perpendicular to the tool axis may be formed as in another example shown in FIG. However, in this case, in order to accurately detect the reference position, it is necessary to perform right-angle plane processing with extremely high accuracy compared to the case where the inclined surface 5 is formed.

  Further, when the right-angled surface 4 is formed, for example, the jig 9 is a substantially U-shaped body in plan view in which an escape recess 10 that escapes the blade portion 1 as shown in FIG. And a substantially hemispherical abutting portion 11 that abuts the right-angled surface 4 at one point. The position detection method and the like are the same as in this embodiment. In this case, as in the present embodiment, as shown in FIGS. 9 and 10, a contact-type position detector 6 ′ capable of pressing the pressure-sensitive portion 7 ′ by the surface 4 that is directly perpendicular, You may employ | adopt the contact-type position detector 6 which has pressure part 7 '. In addition, when a predetermined range (the range in contact with the pressure-sensitive portion 7 ′ or the entire circumference of the tool) of the tip surface of the shank portion 2 or the protrusion can be formed on the surface 4 perpendicular to the tool axis with extremely high accuracy, It is not necessary to provide the protruding portion 11 ′ on the portion 7 ′.

  Since the present embodiment is configured as described above, when the reference position of the tool attached to the spindle of the machining center is detected, the pressure-sensitive portion 7 of the contact-type position detector 6 is directly or healed by the right edge 8. It is possible to detect by pressing indirectly through the tool 9, and therefore, the reference position is detected without contacting the tool tip with the contact-type position detector 6, that is, without damaging the tool tip. This makes it possible to detect the reference position with high accuracy and at a low cost even with a rotating cutter having a very small diameter that is easily broken.

  Therefore, in this embodiment, the reference position can be detected without bringing the tool tip into contact with the contact-type position detector, and even with a very small diameter rotary cutting tool, the contact-type position detector is used and the cost is precise. The reference position can be detected and is extremely practical.

It is a schematic explanatory side view of a tool reference position detection method. It is a schematic explanatory side view of a present Example. It is a rough explanatory perspective view of the jig | tool of a present Example. It is a schematic explanatory drawing of the tool which provided the taper part at the front-end | tip of the shank part. It is a schematic explanatory drawing which shows an example of the contact-type position detector which concerns on a present Example. It is a schematic explanatory drawing which shows an example of the contact-type position detector which concerns on a present Example. It is a schematic explanatory side view of another example. It is a schematic explanatory perspective view of the jig of another example. It is a schematic explanatory drawing which shows an example of the contact-type position detector which concerns on another example. It is a schematic explanatory drawing which shows an example of the contact-type position detector which concerns on another example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blade part 2 Shank part 4 Right angle surface 5 Inclined surface 6 Contact-type position detector 7 Pressure sensing part 9 Jig
10 Recess
11 Contact part
19 Work surface

Claims (7)

  A rotary cutting tool having a blade portion on a distal end side and a shank portion on a proximal end side, wherein the rotation of the tool is provided on the shank portion or a protrusion provided with the blade portion protruding from the shank portion. A rotary cutting tool characterized in that a surface perpendicular to the axis is provided.   A rotary cutting tool having a blade portion on the distal end side and a shank portion on the proximal end side, and the projection provided with the blade portion projecting from the shank portion or the shank portion is closer to the tool center side. A rotary cutting tool characterized in that an inclined surface that is inclined downward toward the tool base end side is provided.   The rotary cutting tool according to any one of claims 1 and 2, wherein the right-angled surface or the inclined surface is positioned radially outward of the blade portion in a tool tip view. Cutting tools.   The rotary cutting tool according to any one of claims 1 to 3, wherein the right-angled surface or the inclined surface is provided at a position near an outer periphery of a tip surface of the shank portion or the protrusion. Rotary cutting tool.   The rotary cutting tool according to any one of claims 1 to 4, wherein the outer diameter of the blade portion is 0.1 mm or less.   Using a contact-type position detector that has a pressure-sensitive portion that is placed on the reference surface and can detect pressure by a rotary cutting tool on the reference surface, with the workpiece surface or a surface whose relative distance to the workpiece surface is known as a reference surface A reference position detection method for detecting a reference position by measuring a relative distance between a tip of a rotary cutting tool attached to a main shaft of a rotary machine tool and the reference surface according to any one of claims 1 to 5. The jig having a concave portion for allowing the blade portion to escape and a contact portion with which a crossed ridge line between the perpendicular surface or the inclined surface and the tool outer peripheral surface abuts is placed on the pressure-sensitive portion. A reference position detection method, wherein the reference position is detected by pressing the contact portion with the right-angled surface or the intersecting ridge line.   Using a contact-type position detector that has a pressure-sensitive portion that is placed on the reference surface and can detect pressure by a rotary cutting tool on the reference surface, with the workpiece surface or a surface whose relative distance to the workpiece surface is known as a reference surface A reference position detection method for detecting a reference position by measuring a relative distance between a tip of a rotary cutting tool attached to a main shaft of a rotary machine tool and the reference surface according to any one of claims 1 to 5. The reference position detecting method, wherein the reference position is detected by directly pressing the pressure-sensitive part by a cross ridge line between the perpendicular surface or the inclined surface and the outer peripheral surface of the tool.

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