JP2007000950A - Cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting tool, capable of controlling the weight, the rigidity and the direction of rigidity, and reducing vibration. <P>SOLUTION: This cutting tool 1 is formed by fitting a cutting blade 3 to the tip of a bar-like member 2, and a removably mounting part 4 for removably mounting a weight body 5 is provided in a part positioned in the direction except the cutting direction P in the bar-like member 2 and in the direction Q orthogonal to the cutting direction P. The removable part 4 is a hole engraved in the radial direction in the peripheral surface of the bar-like member 2, and the weight body 5 is buried in the hole. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cutting tool used for a machine tool such as a lathe.

  One of cutting tools used for lathes and the like is a boring bar called an inner diameter machining tool. Since this boring bar has a cantilever shape overhanging from the tool holder, there is a problem that vibration called chatter vibration is likely to occur depending on cutting conditions, and machining quality is deteriorated. Although weight reduction of the head part of cutting tools, such as a boring bar, is preferable for vibration damping, there exists a problem of a rigidity fall. In view of this, various companies have proposed a device for analyzing the shape of the head portion of the boring bar by simulation analysis and providing dimples so as to obtain high rigidity, light weight, vibration damping effect, and the like.

  However, none of the cutting tools proposed by each company can adjust the weight, rigidity, and direction of rigidity, and depending on the processing conditions, etc., the effect of reducing vibration cannot be obtained sufficiently, or processing due to insufficient rigidity. There are problems such as incurring a decrease in accuracy. Moreover, all are expensive.

An object of the present invention is to provide a cutting tool that can adjust the weight, rigidity, and direction of rigidity and can reduce vibration.
Another object of the present invention is to be able to configure the attaching / detaching portion of the weight body without providing a special means protruding from the outer periphery of the bar-shaped member.
Still another object of the present invention is to make it easy to attach and detach a weight body.

The cutting tool of the present invention is a cutting tool composed of a bar-shaped member with a cutting blade attached to the tip, and the cutting direction in the bar-shaped member, and a portion located in a direction excluding the direction orthogonal to the cutting direction, An attachment / detachment portion for attaching the weight body detachably is provided.
According to this configuration, since the attaching / detaching portion for detachably attaching the weight body is provided, by selecting the attachment / detachment of the weight body, the weight, rigidity and rigidity direction of the cutting tool can be adjusted, and chatter vibration and the like can be adjusted. Vibration can be prevented. In cutting tools, the cutting load acts in the cutting direction, and the reaction force of the load that presses the cutting blade against the workpiece acts in the direction perpendicular to the cutting direction. Since it is provided in a portion located in a direction excluding the direction to perform, the effect of cutting the rigidity of the bar-shaped member due to the provision of the attaching / detaching portion is small. As described above, since the attachment / detachment portion is provided at a place where the influence of the rigidity reduction is small and the weight body can be attached / detached, the balance between the conflicting weight and rigidity can be adjusted. Further, the cost can be suppressed without using a special tool.

  In this invention, the said attachment / detachment part is a hole carved by radial direction with respect to the surrounding surface of a bar-shaped member, and a weight body may be buried in this hole. Thus, when the detachable portion is a hole, the weight body can be easily attached without providing a special means that protrudes from the outer periphery of the bar-shaped member.

  When the attachment / detachment portion is a hole as described above, the hole is formed by tapping an internal thread portion on the inner peripheral surface thereof, and the weight body is formed by forming an external thread portion that meshes with the internal thread portion. May be. Thus, when the internal thread part is formed in the hole, it can be attached and detached by screwing the weight body into the attaching / detaching part, and the attaching / detaching work can be easily performed.

The cutting tool of the present invention is a cutting tool composed of a bar-shaped member with a cutting blade attached to the tip, and the cutting direction in the bar-shaped member, and a portion located in a direction excluding the direction orthogonal to the cutting direction, Since the attachment / detachment part for detachably attaching the weight body is provided, the weight, rigidity, and direction of rigidity can be adjusted, and vibration can be reduced.
When the attaching / detaching portion is a hole carved in the radial direction with respect to the circumferential surface of the bar-shaped member, and the weight body is buried in the hole, a special case that protrudes from the outer periphery of the bar-shaped member. The weight body can be easily attached without providing means.
When the hole serving as the attaching / detaching portion is formed by tapping a female screw portion on an inner peripheral surface thereof, and the weight body is formed with a male screw portion that meshes with the female screw portion, the attaching / detaching operation of the weight body is performed. Can be done easily.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing the main part of the cutting tool of this embodiment. This cutting tool 1 is called a boring bar used at the time of inner diameter processing, and a cutting blade 3 is attached to a tip extending from a columnar base portion 2 a of a bar-like member 2. The cutting tool 1 has a head portion 2b, which is a portion closer to the tip side than the cylindrical base portion 2a, having a shape in which the cross section gradually becomes smaller toward the tip side than the columnar base portion 2a. A cutting blade fitting portion 2b to which the blade 3 is fitted is provided. The cutting edge 3 has a side edge at the front end serving as a cutting edge 3a, and is fixed to the bar-like member 2 by a set screw 6 in a state of being fitted into the cutting edge fitting recess 2b.

  A plurality of attaching / detaching portions 4 to which the weight body 5 is detachably attached are provided on the columnar base portion 2 a of the bar-like member 2. FIG. 2 shows a cross section of the cylindrical base portion 2a, and in this figure, a cross sectional view of the cutting blade 3 is overlapped with an imaginary line. In the figure, the direction of the arrow P is the cutting direction in the bar-shaped member 2. This cutting direction P is a tangential direction of a point of the cutting edge 3a in a circle passing through the cutting edge 3a of the cutting edge 3 with the axis O of the cylindrical base 2a as the center.

Each of the attachment / detachment portions 4 includes a hole carved in the radial direction with respect to the peripheral surface of the columnar base portion 2a of the bar-like member 2. These attaching / detaching portions 4 are provided in portions of the bar-shaped member 2 that are located in directions other than the cutting direction P and the direction Q perpendicular to the cutting direction. The weight body 5 is buried in each of the attachment / detachment portions 4 formed of the holes. Specifically, four locations inclined by 45 ° with respect to a line segment N extending in the cutting direction P from the axis O of the cylindrical base portion 2a of the bar-shaped member 2, that is, four locations separated by a circumferential angle of 90 degrees. The attachment / detachment portions 4 are provided at four positions (a total of eight positions) shifted from the respective positions by a predetermined dimension in the axial direction as shown in FIG. In other words, the attachment / detachment portion 4 is located at a position deviated from the line segment N in the cutting direction P passing through the axis O and the line segment (Q) perpendicular to the line segment N.
A female threaded portion 4a is tapped on the inner peripheral surface of each detachable portion 4 formed of a hole, and a weighted body 5 is formed with a male threaded portion 5a that meshes with the female threaded portion 4a. The weight body 5 is a double-sided bolt-like member that is substantially entirely contained in the attaching / detaching portion 4. The weight body 5 can be freely attached to and detached from each attaching / detaching portion 4 by screwing the male screw portion 5a of the weight body 5 with the female screw portion 4a of the attaching / detaching portion 4 or by releasing the screwing.

  FIG. 3 is a partial plan view schematically showing an example of a lathe 11 in which the cutting tool 1 is used. The lathe 11 includes a main shaft 12 and a turret tool post 13. The main shaft 12 has a main shaft chuck 14 at its tip, and is driven to rotate by gripping the workpiece W by the main shaft chuck 14. The turret tool post 13 is movable in a direction along the spindle axis (Z-axis direction) and a horizontal direction (X-axis direction) perpendicular to the spindle axis via a feed base (not shown). The turret tool post 13 has a drum-like shape with a polygonal front shape, and a tool is installed at each tool station including a peripheral surface portion between each corner. As one of the tools, FIG. 3 shows a state where the cutting tool 1 is installed. The cutting tool 1 is attached to the turret tool post 13 via a tool holder 15, and is attached so as to protrude from the tool holder 15 in a direction parallel to the axis of the main shaft 12. In the turning process of the workpiece W using the cutting tool 1 by the lathe 11, the inner diameter surface processing of the recess Wa on the front end surface of the workpiece W is performed.

  According to the cutting tool 1 having this configuration, since a plurality of attachment / detachment portions 4 for detachably attaching the weight body 5 to the bar-like member 2 are provided, the attachment / detachment of the weight body 5 and the attachment / detachment location are selected. The overall weight, rigidity, and direction of rigidity can be adjusted freely. Therefore, vibration such as chatter vibration can be prevented. In the cutting tool 1, the weight reduction in the vicinity of the head portion 2b is preferable for vibration damping, but if the meat is cut for weight reduction, there is a problem of a decrease in rigidity. In the cutting tool 1, the cutting load acts in the cutting direction P, and the reaction force of the load that presses the cutting blade 3 against the workpiece W also acts in the direction Q orthogonal to the cutting direction P. However, since the cutting tool 1 is provided with the attaching / detaching portion 4 in a portion other than the cutting direction P and the direction orthogonal to the cutting direction P, the rigidity of the bar-like member 2 due to the provision of the attaching / detaching portion 4 is provided. Less impact on cutting. As described above, since the attaching / detaching portion 4 is provided at a place where the influence of the rigidity reduction is small and the weight body 5 is attachable / detachable, the balance between the conflicting weight and rigidity can be adjusted. Moreover, the natural frequency of the cutting tool 1 is changed by attaching and detaching the weight body 5, and chatter vibration due to resonance can be reduced. Furthermore, it is not necessary to use a special tool, and the cutting tool 1 can be made with a simple configuration, and the cost can be reduced.

  In this embodiment, the attaching / detaching portion 4 is a hole carved in the radial direction with respect to the peripheral surface of the bar-shaped member 2, and the weight body 5 is buried in the hole. The weight body 5 can be easily attached without providing any special means that protrudes from.

  Moreover, since the female screw part 4a is tapped in the hole used as the attachment / detachment part 4, and the weight body 5 is formed with the male screw part 5a which meshes with the said female screw part 4a, the weight body 5 is attached or detached. The operation of attaching to and detaching from the unit 4 can be easily performed.

It is a perspective view which shows the principal part of the cutting tool concerning one Embodiment of this invention. It is sectional drawing of the cylindrical base part of the bar-shaped member in the cutting tool. It is a partial top view of the lathe using the cutting tool.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cutting tool 2 ... Bar-shaped member 3 ... Cutting blade 4 ... Detachable part 4a ... Female thread part 5 ... Weight body 5a ... Male thread part P ... Cutting direction Q ... Direction orthogonal to cutting direction

Claims (3)

  A cutting tool comprising a bar-like member having a cutting blade attached to the tip, wherein a weight body is detachably attached to a portion of the bar-like member located in a direction excluding a cutting direction and a direction perpendicular to the cutting direction. A cutting tool provided with a detachable part.   The cutting tool according to claim 1, wherein the detachable portion is a hole carved in a radial direction with respect to the peripheral surface of the bar-shaped member, and the weight body is buried in the hole. The cutting tool according to claim 2, wherein the hole is formed by tapping a female screw portion on an inner peripheral surface thereof, and the weight body is formed by a male screw portion that meshes with the female screw portion.

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