JP5363847B2 - Reaming tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reaming cutting tool preventing chattering at an aperture inlet port during machining. <P>SOLUTION: A blade face 7 of a tip part 5a in an axial direction of a metallic tip 5 configuring a grinding tool 3 is formed into a male tapered face having a diameter that becomes smaller toward a tip end, and a slit 8 opening toward the tip end direction is formed at the tip part 5a in the axial direction. The slit 8 is formed, and the blade tip rigidity at the tip part becomes smaller, and force from the outside works to more easily deform the tip part inward in the diametrical direction. As a result, even when the rotation center C1 of the machining cutting tool shifts from the center C2 of the aperture, the tip part 5a is deformed inward in the diametrical direction when the machining cutting tool advances and the tip end of the grinding tool 3 abuts to the inlet port of the aperture, thus making the machining cutting tool enter the aperture without causing chattering even when the grinding tool 3 rotates at high speed. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a reaming tool having a feature in the structure of a cartridge type grindstone.

  There are two types of reamer processing that feeds and processes in the axial direction while rotating a cutting tool having a diameter larger than that of a hole formed in a workpiece by a drill or the like, and processing that finishes the surface properties of the hole. The grindstone used for the former is required to have rigidity to grind the workpiece to some extent. Therefore, as shown in FIG. 5A, the abrasive grains 101 are fixed to the surface of the solid metal chip 100 by brazing or electrodeposition.

  On the other hand, in the process of finishing the surface properties of the hole, it is required that the hole can be deformed in the radial direction following the surface of the hole. For example, as shown in FIG. Forming. This structure is also disclosed in Patent Document 1.

  Further, Patent Document 2 describes that two cantilever beams are stacked in two stages so that the fulcrum positions are opposite by inserting a slit in a grindstone chip. This is the same as Document 1.

Japanese Patent No. 2680436 JP 2006-102855 A

When performing reaming using a grindstone having a structure that is not easily deformed in the radial direction as shown in FIG. 5A, the grindstone is not guided until the tip of the grindstone bites into the hole entrance of the workpiece. There is a case where chatter (vibration) occurs due to contact between a grindstone rotating with a large load fluctuation and a workpiece, and accurate machining may not be performed.
Further, when the workpiece material changes in the middle of the hole, for example, when reaming is performed on a hole formed in a workpiece in which aluminum and iron are joined, the cutting resistance may change and vibration may occur.

  On the other hand, when reaming is performed using a grindstone having a structure that is easily deformed in the radial direction as shown in FIG. 5B, chattering does not occur, but deformation occurs following the hole shape. And the center of the blade will be misaligned, and accurate grinding accuracy cannot be achieved.

In order to solve the above-mentioned problems, the reaming tool according to the present invention reduces the rigidity of the blade edge at one end or both ends in the axial direction of a grindstone that can be attached to and detached from the holder, and the one end or both ends are ground during grinding. It was easily deformed radially inward under pressure.
The term “blade edge rigidity” as used herein refers to the difficulty of displacement of the blade edge in the radial direction and the circumferential direction due to the reaction force from the workpiece during grinding.

As means for making the blade edge rigidity smaller than other parts and making it easier to deform radially inward, it is conceivable to form a slit or gradually reduce the thickness toward the tip. The direction of the slit may be either the axial direction or the radial direction.

According to the reaming tool according to the present invention, since the edge rigidity of the end of the grindstone that first hits the hole entrance is reduced, even if the rotation center of the grindstone and the axis of the hole are misaligned, the tip of the grindstone Is deformed into a diameter method and the deviation is absorbed to start grinding. For this reason, generation | occurrence | production of chatter can be suppressed.
In particular, even when the workpiece is made of a different material, vibration can be suppressed even if the cutting resistance changes.

In addition, after grinding is started, the grindstone is guided by the hole to be ground and reaming is performed. At this time, the central portion in the axial direction of the grindstone to be ground has high edge rigidity and radial direction. Therefore, the hole machining accuracy can be increased.

Sectional view of a reamer cutting tool according to the present invention Perspective view of a cartridge-type grinding wheel that constitutes the reaming tool (A) And (b) is the figure explaining the effect | action of the reamer cutting tool which concerns on this invention (A)-(c) is a side view of the grindstone concerning another example. (A) And (b) is a side view of a conventional grindstone

Embodiments of the present invention will be described below with reference to the accompanying drawings. The reaming tool according to the present invention has a plurality of cartridge-type grindstones 3 attached to an outer peripheral surface of a shaft 1 that can be rotated at a high speed by bolts 2 so as to be replaceable in a circumferential direction.

As a processing cutting tool, the radial position of the grindstone 3 is held in a cylindrical holder so that adjustment is possible, and the amount of protrusion of the grindstone 3 from the surface of the cylindrical holder is moved by moving the draw bar inserted in the cylindrical holder in the axial direction. The type may be adjusted.

The grindstone 3 has abrasive grains 6 fixed to the surface of the metal tip 5 having a substantially plate shape. As the abrasive grains 6, for example, diamond abrasive grains or CBN may be aligned and fixed by electrodeposition, but is not limited thereto.

  Further, the blade surface 7 of the tip portion 5a in the axial direction of the metal tip 5 is a male taper surface having a smaller diameter toward the tip, and a slit 8 opened in the tip direction is formed in the tip portion 5a in the axial direction. Yes. As a result of the formation of the slits 8, the cutting edge rigidity of the tip portion is reduced, and the force from the outside acts to facilitate deformation inward in the radial direction.

  The tip 5a of the grindstone 3 is tapered in order to disperse the machining allowance, and the amount of abrasive grains 6 fixed to the surface of the tip 5a may be reduced.

  When machining the hole formed in the workpiece using the above reaming tool, even if the rotation center C1 of the machining tool and the center C2 of the hole are shifted as shown in FIG. When the cutting tool advances and the tip of the grindstone 3 hits the entrance of the hole, the tip 5a is deformed radially inward to reduce the processing load, as shown in FIG. Therefore, even if the grindstone 3 is rotating at a high speed, the processing blade can enter the hole without chattering.

Since no slit is formed in the central portion 5b of the metal tip 5 in the axial direction, the cutting edge has high rigidity and does not deform in the radial direction. As a result, the inner circumference of the hole is accurately ground and dimensioned with high accuracy.

  4 (a) to 4 (c) are side views of a grindstone according to another embodiment, and the embodiment shown in FIG. 4 (a) is a processing blade suitable for processing a through hole. In other words, the metal chip 5 is simply chamfered 5c without providing a tapered portion, and slits 9, 9 extending in the axial direction are formed at both ends. Since the grindstone 3 according to this embodiment is easily deformed at both ends and the cutting edge rigidity at the center is high, it can be said that the grindstone 3 is effective for a machining method in which the grindstone rotates and reciprocates through the through hole.

In another embodiment shown in FIG. 4B, the outer surface of the tip portion 5a of the metal tip 5 is formed as a male taper surface that gradually decreases in diameter toward the tip without forming a slit. The side surface is a female tapered surface that gradually increases in diameter toward the tip, and the cutting edge rigidity of the tip portion 5a is reduced.

In another embodiment shown in FIG. 4C, the tip portion 5a is formed by reducing the thickness of the tip portion 5a of the chip 5 and forming the radial slit 10 at the boundary between the tip portion 5a and the central portion 5b. The cutting edge rigidity is made smaller than other parts.

The reaming cutting tool according to the present invention can be used for processing for enlarging a hole formed in a workpiece or for accurately adjusting a hole diameter.

DESCRIPTION OF SYMBOLS 1 ... Axis, 2 ... Bolt, 3 ... Grinding stone, 5 ... Metal tip, 5a ... Tip part of tip, 5b ... Center part of tip, 5c ... Chamfering, 6 ... Abrasive grain, 7 ... Blade surface, 8, 9, 10 ... slit, C1 ... center of rotation of the cutting tool, C2 ... center of the hole.

Claims (2)

In a reamer cutting tool for grinding the inner periphery of a hole formed in a workpiece, the reamer cutting tool is attached to an outer peripheral surface of a shaft on which a grindstone can rotate at a high speed or a cylindrical holder so that a radial position can be adjusted. Alternatively, the cutting edge rigidity of one end or both ends of the grindstone along the cylindrical holder is reduced, and the one end or both ends are deformed radially inward under pressure during grinding. . In reaming cutting tool according to claim 1, it means smaller than the other portions of the cutting edge stiffness one or both ends of the grinding wheel, gradually reducing the thickness toward or tip to form a slit A reamer cutting tool characterized by that.