JP2008036731A - Cutting tool and cutting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting tool which supplies oil mist to a machining point simultaneously with the switching-on of a mist discharging switch, and reduces a cycle time in cutting. <P>SOLUTION: The cutting tool 1 carries out a cutting operation by means of cutting edges 7, 8 fixed to the outer peripheral surface 4a of a rotating tool body 4, and cuts a workpiece while spraying the oil mist toward the machining point. The tool body 4 is provided with: cutting oil supply passages 9, 10 which have openings 12, 13 in the neighbor hood of the cutting edges 7, 8 and supply the cutting oil up to the opening 12, 13 in the state of liquid; and an air supply passage 11 which is communicated with the openings 12, 13 of the cutting oil supply passages 9, 10 and has jetting ports 14, 15 on the outer peripheral surface 4a. The cutting oil and the air are mixed to produce the oil mist at the intersecting points of the cutting oil supply passages 9, 10 and the air supply passage 11 by the centrifugal force and the negative pressure caused by the rotation of the tool body 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cutting tool and a cutting method for performing grinding while mixing cutting oil with air and spraying it in a mist form.

  A cylinder block bore fine boring tool (hereinafter simply referred to as a boring tool) is a device for cutting an inner wall of a cylinder, and has roughing and finishing tools at both ends.

  With this boring tool, the roughing tool is lowered while rotating in contact with the workpiece to perform roughing, and the finishing tool protrudes at the lower end of the cylinder and is raised while rotating in contact with the workpiece. Processing.

At this time, processing is performed while supplying a very small amount of mist-like cutting oil (oil mist) from the piping formed inside the boring tool to the processing point. The oil mist is generated by mixing cutting oil and air outside the tool, and is supplied to a processing point through piping inside the tool. As a cutting tool for performing a cutting process by spraying oil mist on a processing point, for example, a technique described in Patent Document 1 is disclosed.
JP 2005-81459 A

  However, with the cutting tool described above, when the mist discharge switch is turned on at the number of revolutions for boring, the mist discharge response is poor, and oil mist is discharged 2-3 minutes after the switch is turned on. For this reason, with this cutting tool, if a practical cycle time of a mass production line is assumed, the cycle time cannot be shortened.

  The reason for this is that the tool rotates at a high speed and the piping for supplying oil mist is cylindrical and the wall surface is straight, so that the oil mist collides and liquefies on the wall surface due to the centrifugal force due to rotation. However, oil mist is not supplied to the processing point at the same time as the mist discharge switch is turned on.

  Therefore, the present invention provides a cutting tool and a cutting method capable of supplying oil mist to a machining point at the same time as turning on a mist discharge switch and shortening a cycle time in cutting.

  The present invention relates to a cutting tool for performing grinding while spraying oil mist toward a processing point for grinding a workpiece with a cutting edge fixed to an outer peripheral surface of a rotating tool body, the tool body including the cutting edge. A cutting oil supply path for supplying cutting oil in an oil state to the opening, and an air supply path connected to the opening of the cutting oil supply path and having a jet outlet on the outer peripheral surface. The cutting oil and the air are mixed at an intersection of the cutting oil supply path and the air supply path by an centrifugal force and a negative pressure generated by the rotation of the tool body to form an oil mist. .

  According to the present invention, the opening of the cutting oil supply passage is provided in the vicinity of the cutting edge, and the cutting oil supplied to the opening in the oil state at the intersection of the cutting oil supply passage and the air supply passage and the air supply Since oil mist is mixed with the air supplied from the road, the oil mist can be supplied to the processing point with good response without adhering to the inner wall of the road. Therefore, according to the present invention, the cycle time in cutting can be shortened.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

  1 is a front view showing a cutting tool of the present embodiment, FIG. 2 is a cross-sectional view of the cutting tool of the present embodiment, FIG. 3 is an enlarged cross-sectional view of the main part at the position AA in FIG. FIG. 5 is a diagram for determining the inclination angle of the air supply path at the intersection of the cutting oil supply path and the air supply path. FIG. 5 shows the discharge time and oil mist discharge amount when the mist discharge switch is turned on with a conventional cutting tool. FIG. 6 is a view showing a state in which oil mist is attached to the inner wall of the road.

  A cutting tool 1 according to the present embodiment is for grinding an inner surface 3a of a cylinder liner 3 provided in a cylinder bore of a cylinder block 2, which is a work piece, for example, and a tool body 4 inserted into the cylinder bore, And a mounting portion 5 for chucking the tool body 4 on the rotation mechanism portion.

  The tool main body 4 is formed as a cylindrical body having a recess 6 at a substantially central portion in the axial direction, and two cutting edges 7 and 8 are provided at positions near the lower end of the outer peripheral surface 4a. Of these cutting edges 7 and 8, one is used for roughing and the other is used for finishing.

  The mounting portion 5 is formed as a cylindrical body having a diameter larger than that of the tool body 4 and having a lower height, and is integrated with the tool body 4.

  As shown in FIG. 2, the tool body 4 is supplied to the cutting oil supply passages 9 and 10 for supplying the cutting oil to the respective cutting edges 7 and 8, and the cutting oil supply passages 9 and 10. There is provided an air supply path 11 for supplying air to the cutting oil to be oil mist.

  The cutting oil supply passages 9 and 10 include vertical passages 9A and 10A formed from the end surface 5a of the mounting portion 5 to the lower end parallel to the axis of the tool body 4, and cutting edges 7 from the lower ends of the vertical passages 9A and 10A. , 8 and the slopes 9B and 10B, and the openings 12 and 13 of the slopes 9B and 10B are the vicinity of the cutting edges 7 and 8, respectively.

  The vertical paths 9A and 10A are respectively provided on both sides of a vertical path 11A of an air supply path 11 described later. The inclined paths 9B and 10B are formed obliquely downward toward the outer peripheral surface 4a of the tool body 4 so that the cutting oil naturally flows to the vicinity of the cutting edges 7 and 8 by gravity. The cutting oil supply passages 9 and 10 are configured by embedding a cylindrical flow channel pipe through which cutting oil is circulated in the cutting tool 1.

  As shown in FIG. 3, the flow path pipe 16 protrudes into the branch pipes 11B and 11C of the air supply path 11 described later. An oil outlet 17 for ejecting cutting oil toward the openings 12 and 13 is formed on the side surface of the flow channel pipe 16 protruding into the branch pipes 11B and 11C. The oil jet port 17 has an extremely small hole diameter with respect to the flow path diameters of the branch pipes 11B and 11C, and has an optimum size for mixing with air to form a mist.

  The air supply path 11 includes a vertical path 11A formed from the end surface 5a of the mounting portion 5 to the lower end along the axial center of the tool body 4, and a branch path that branches from the vertical path 11A to the cutting edges 7 and 8. 11B and 11C, and the spouts 14 and 15 which are the front ends of the branch paths 11B and 11C are opened in the outer peripheral surface 4a of the tool body 4.

  The branch paths 11 </ b> B and 11 </ b> C are connected to the openings 12 and 13 of the cutting oil supply paths 9 and 10, and are inclined with a predetermined inclination angle θ with respect to the axial center of the tool body 4. As shown in FIG. 4, the inclination angle θ is determined by the centrifugal force F1 when the tool body 4 rotates, the air ejection force F2 that ejects air, the gravity F3 that acts on the oil mist OM, and the oil mist by the tool moving speed. It is determined by the force F4 acting on.

  That is, the inclination angle θ includes the total force F12 of the centrifugal force F1 acting on the oil mist OM and the air blowing force F2, the gravity F3 acting on the oil mist OM, and the force F4 acting on the oil mist OM due to the tool moving speed. The total force F34 and the resultant force F are determined.

  In this cutting tool 1, the inner surface 3 a of the cylinder liner 3 and the cutting edges 7, 8 are rotated while being lowered and roughed with a cutting edge for roughing, and then finished at the lower end of the cylinder bore. Finishing is performed while the cutting edge for use protrudes and then rises. At the time of cutting, the mist discharge switch is turned on, and oil mist is ejected from the ejection ports 14 and 15 provided in the vicinity of the cutting edges 7 and 8 toward the machining point.

  At this time, when oil mist mixed with cutting oil and air is supplied to the outside of the cutting tool 1 through a flow path provided inside the tool body, as shown in FIG. Even if it is turned on, the oil mist is not immediately ejected, and after a while (after 2 to 3 minutes), the oil mist is discharged. This is because, as shown in FIG. 6, the oil mist OM collides with the inner wall 18a of the flow path 18 and liquefies, and the liquefied mist OM1 adheres to the inner wall 18a.

  In the present embodiment, the oil and mist are not supplied to the flow path formed in the cutting tool 1, but the cutting oil and the air are respectively supplied through separate paths, and in the vicinity of the ejection ports 14 and 15. These cutting oil and air are mixed to form a mist, and the mist of the oil mist OM is ejected to a processing point. Specifically, the cutting oil is supplied to the cutting oil supply paths 9 and 10 which are separate paths from the air supply path 11. The cutting oil supplied to the cutting oil supply passages 9 and 10 flows from the vertical passages 9A and 10A to the inclined passages 9B and 10B by the weight of the oil while maintaining the state of the oil. The oil is held in the openings 12 and 13 by the surface tension of the oil.

  When the cutting tool 1 is rotated from the stopped state and air is supplied to the air supply path 11, the air flows from the vertical path 11A to the branch pipes 11B and 11C. The cutting oil ejected from the oil ejection port 17 formed in the flow channel pipe 16 protruding into the branch pipes 11B and 11C due to the supplied air and the centrifugal force and negative pressure due to the rotation of the tool body 4 is The mist is converted into oil mist OM and ejected from the ejection ports 14 and 15 toward the processing point.

  Thus, according to the present embodiment, the openings 12 and 13 of the cutting oil supply passages 9 and 10 are provided in the vicinity of the cutting edges 7 and 8, and the cutting oil supply passages 9 and 10 and the air supply passage 11 are provided. At the intersection, the cutting oil supplied to the openings 12 and 13 in the oil state and the air supplied from the air supply path 11 are mixed to form an oil mist OM, so that the response is good without adhering to the road inner wall. Oil mist OM can be supplied to the processing point. Therefore, according to the present invention, the cycle time in cutting can be shortened.

  Further, according to the present embodiment, the branch pipes 11B and 11C, which are supply paths at the intersections of the cutting oil supply paths 9 and 10 and the air supply path 11, are inclined with respect to the axial center of the tool body 4. The oil mist OM can be supplied to the processing point without colliding with the road inner wall.

It is a front view which shows the cutting tool of this Embodiment. It is sectional drawing of the cutting tool of this Embodiment. It is a principal part expanded sectional view in the AA line position of FIG. It is a figure for determining the inclination-angle of this air supply path in the intersection part of a cutting oil supply path and an air supply path. It is a figure which shows the discharge time and oil mist discharge amount when a mist discharge switch is turned on with the cutting tool of the conventional structure. It is a figure which shows the state which the oil mist adhered to the road inner wall.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cutting tool 2 ... Cylinder block 3 ... Cylinder liner (work material)
DESCRIPTION OF SYMBOLS 4 ... Tool main body 5 ... Mounting part 7, 8 ... Cutting edge 9, 10 ... Cutting oil supply path 11 ... Air supply path 11B, 11C ... Branch path 12, 13 ... Opening 14, 15 ... Jet outlet 17 ... Oil jet outlet

Claims (5)

In a cutting tool that performs grinding while spraying oil mist toward a processing point for grinding a workpiece with a cutting edge fixed to the outer peripheral surface of a rotating tool body,
The tool body has an opening in the vicinity of the cutting edge, a cutting oil supply passage for supplying cutting oil in an oil state to the opening, and an outer peripheral surface connected to the opening of the cutting oil supply passage. And an air supply path having a spout in the
A cutting tool, wherein the cutting oil and the air are mixed at an intersection of the cutting oil supply path and the air supply path by an centrifugal force and a negative pressure generated by the rotation of the tool body to form an oil mist. The cutting tool according to claim 1,
The cutting tool characterized in that the supply path at the intersection of the cutting oil supply path and the air supply path among the air supply paths is inclined with respect to the axial center of the tool body. The cutting tool according to claim 2,
The inclination angle is determined by a centrifugal force when the tool body rotates, an air blowing force for blowing the air, a gravity acting on the oil mist, and a tool moving speed. . The cutting tool according to any one of claims 1 to 3,
The cutting tool is characterized in that at least two cutting edges are provided in the tool body, one of which is a roughing cutting edge and the other is a finishing cutting edge. In a cutting method in which grinding is performed while oil mist is sprayed toward a processing point for grinding a workpiece with a cutting edge fixed to the outer peripheral surface of a rotating tool body,
The cutting force in the oil state is mixed with air in the vicinity of the machining point to be mist by centrifugal force and negative pressure due to the rotation of the tool body, and the mist of the oil mist is jetted to the machining point. Cutting method to do.

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