JP2007320013A - Boring tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a boring tool which excellently discharges chips, and suppresses a degradation in the stiffness of a shank. <P>SOLUTION: In the boring tool, at least one of pockets 30, 40 is provided such that, in the plan view from a rake face 22 side, the pockets 30, 40 extend from an outer peripheral portion 21 toward the opposite side of the outer peripheral portion 21 in the peripheral direction with the distance from the front end side of the shank toward the rear end side of the shank, and their extending direction P is tilted with respect to the axis of the shank 1. A rib 60 is extended from the front end side of the shank toward the rear end side of the shank so as to adjoin the pockets 30, 40 and so as to project upward to be higher than a rake face 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a boring tool for performing inner diameter processing of an inner diameter portion of a work material.

When boring the inner diameter portion provided in the work material, there is a problem that generated chips are caught between the tool and the machining surface, and the machining surface is damaged or the dimensional accuracy is deteriorated.
As a countermeasure, a chip pocket for storing chips or discharging them to the outside is provided. Although the chip pocket can store a relatively large amount of chips if the volume is increased, the rigidity of the tip of the shank is reduced to cause tool chatter, which causes deterioration in dimensional accuracy.

  For example, in Patent Document 1, a chip pocket 6 is formed on the outer periphery of the cutting edge side of the head portion 3 of the boring tool 1 having a tip 11 attached to the tip, and a concave groove is formed on the outer peripheral surface on the opposite side in the circumferential direction with respect to the cutting blade. 15 is provided to reduce the weight of the head portion 3, thereby suppressing vibration due to chatter.

Moreover, in patent document 2, the 1st subpocket 1 and the 2nd subpocket are provided in the front-end | tip of the holder 7, the holder outer periphery by the side of the blade edge | tip 3 of the cutting-tip tip 6, and the holder outer periphery on the opposite side to the blade edge 3 in the circumferential direction. 2 is positioned above the blade edge 3 and a rib 5 is formed between the first sub-pocket 1 and the second sub-pocket 2 to suppress a decrease in rigidity.
JP 2001-105204 A (FIG. 2) Japanese Patent Laying-Open No. 2005-279855 (FIG. 1)

  However, in the boring tool described in Patent Document 1, the concave groove 15 provided on the outer circumferential surface on the opposite side in the circumferential direction with respect to the cutting edge is separated from the chip pocket 6 by the rib portion 22A. It contributes little to improving emissions. Therefore, most of the chips travel along the chip pocket 6 provided on the cutting edge side and are discharged from the space generated between the outer peripheral surface of the head portion 3 located on the cutting edge side and the processing surface. Since the space is narrow, there is a problem in that the quality of the processed surface is deteriorated by being caught between the outer peripheral surface and the processed surface. Further, when the cut portion 21 is formed between the concave groove 15 and the chip pocket 6, the cross-sectional area of the rib portion 22A is reduced, and the effect of suppressing the occurrence of chatter is reduced. There was a risk of deterioration of surface quality.

  Further, in the boring tool described in Patent Document 2, finely divided chips are likely to flow into the second auxiliary pocket 2 provided on the outer periphery of the holder on the blade tip 3 side, and further positioned on the blade tip 3 side. Since a sufficient space cannot be secured between the outer peripheral surface of the holder and the inner peripheral surface of the inner diameter portion of the work material, there is a possibility that the machining surface quality is deteriorated by biting chips.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a boring tool capable of improving chip discharging performance and suppressing a decrease in rigidity.

In order to solve the above-mentioned problems, the invention of claim 1 is directed to a tip seat (10) comprising a notch step portion at a tip end portion (2) provided on a tip end side of a substantially bar-shaped shank (1). A throwaway tip (20) having a cutting edge is detachably attached to the tip seat (10), and is located on the outer peripheral side of the tool of the cutting edge by the cutting edge outer peripheral portion (21) responsible for cutting. In the boring tool that cuts the inner peripheral surface of the inner diameter portion (W) of the work material, the shank tip (2) has a shank tip (22) side, as viewed from the rake face (22) side, from the shank tip side to the shank rear end side Extends toward the opposite side in the circumferential direction of the cutting blade outer peripheral portion (21), and the extending direction (P) is inclined with respect to the axis of the shank (1). At least one pocket (30, 40) provided, A rib (60) adjacent to the ket (30, 40) and projecting upward from the rake face (22) extends from the front end side of the shank toward the rear end side of the shank. It is a bore tool.
According to this invention, as it goes from the front end side of the shank to the rear end side of the shank, the pocket extends while inclining in the direction from the cutting blade outer peripheral portion (21) side toward the circumferential direction opposite side of the cutting blade outer peripheral portion (21). (30) guides and discharges the chips generated during processing to the opposite side in the circumferential direction of the cutting edge outer peripheral portion (21). On the opposite side in the circumferential direction on the cutting blade outer peripheral portion (21) side, there is a larger space between the shank outer peripheral surface (4b) and the inner peripheral surface of the inner diameter portion (W) than on the cutting blade outer peripheral portion (21) side. Since it is ensured, the chips are smoothly discharged without being bitten. Since the chip discharging performance is thus improved, the machined surface accuracy and the machined surface quality can be maintained.
Further, the rib (60) adjacent to the pockets (30, 40) and protruding upward from the rake face (22) extends from the shank tip side toward the shank rear end side. Since the rigidity reduction of the tip (2) is suppressed, tool chatter is suppressed, and deterioration of the machining accuracy and the machined surface quality is suppressed.

The boring tool according to claim 2, wherein the rib (60) is formed so as to gradually increase in width from the shank tip side to the shank rear end side. .
According to the boring tool of the second aspect, since the rigidity reduction of the shank tip (2) is effectively suppressed, tool chatter is suppressed, and deterioration of processing accuracy and processing surface quality is significantly suppressed.

The boring tool according to claim 3, wherein at least one flow path (71) directed to the outer peripheral portion (21) of the cutting edge is provided in the shank (1), and the flow path (71) is provided. The boring tool according to claim 1 or 2, wherein the boring tool is formed in the inside of the rib (60) at the shank tip (2).
According to the boring tool according to claim 3, fluids such as cutting oil, air, or mist discharged from the flow path (71) toward the outer periphery of the cutting blade (21) are the outer periphery of the cutting blade (21) and Since the chips are removed from the vicinity and guided to the pockets (30, 40), the chip discharge performance is extremely good, and the deterioration of the machining accuracy and the quality of the machined surface is effectively suppressed.
Further, since the flow path (71) is drilled inside the rib (60), the rigidity of the shank tip (2) is prevented from being lowered, so that tool chatter is less likely to occur and the machining accuracy and the quality of the machined surface are deteriorated. Is suppressed.

According to the boring tool of the present invention, as it goes from the front end side of the shank to the rear end side of the shank, it inclines in the direction from the cutting blade outer peripheral portion (21) side toward the circumferential direction opposite side of the cutting blade outer peripheral portion (21). The pockets (30, 40) extending in this way guide and discharge the chips generated during the processing to the circumferential direction opposite side of the cutting blade outer peripheral portion (21). On the opposite side in the circumferential direction on the cutting blade outer peripheral portion (21) side, there is a larger space between the shank outer peripheral surface (4b) and the inner peripheral surface of the inner diameter portion (W) than on the cutting blade outer peripheral portion (21) side. Since it is ensured, the chips are smoothly discharged without being bitten. Since the chip discharging performance is thus improved, the machined surface accuracy and the machined surface quality can be maintained.
Further, a rib (30) between the pocket (30, 40) and the second pocket (50) protrudes upward from the rake face (22) and extends from the shank tip side toward the shank rear end side ( The provision of 60) suppresses a decrease in the rigidity of the shank tip (2), so that tool chatter is suppressed and deterioration of processing accuracy and processing surface quality is suppressed.

Hereinafter, a boring tool according to an embodiment of the present invention will be described with reference to FIGS.
In the perspective view of FIG. 1 and the plan view of FIG. 2, a tip seat 10 made of a notch step portion having a V shape in plan view is provided on the tip side portion of the shank tip portion 2 of the shank 1 having a substantially round bar shape. It has been. The throwaway tip 20 having an equilateral triangular plate shape is positioned and tightened by seating the lower surface on the bottom surface 11 of the chip seat 10 and abutting a pair of adjacent peripheral surfaces with the restraining surface 12 rising upward from the bottom surface 11. The screw 5 is detachably mounted on the chip seat 10. The throw-away tip 20 has a triangular face on the upper surface as a rake face 22, and at each apex of the triangular face, three sets of a 60 ° nose R portion and a pair of side ridge portions respectively extending from the nose R portion. This is a positive tip which has a peripheral edge extending from the cutting edge as a flank 23 and is inclined inward of the throw-away tip 20 as the flank 23 faces the lower surface. When the throw-away tip 20 is attached to the tip seat 10, the nose R portion and the side ridge portion of the cutting blade disposed on the outer periphery of the tip of the shank tip 2 are respectively connected to the shank tip surface 3 and the shank outer periphery 4a. The cutting edge outer peripheral portion 21 protrudes and cuts the inner peripheral surface of the inner diameter portion W.

The shank tip 2 is formed with two pockets 30 and 40 and one sub-pocket so as to cut out the outer peripheral surface of the shank.
Of the two pockets 30 and 40, the tip side pocket 30 provided around the tip seat 10 is the cutting blade outer peripheral portion 21 side as it goes from the shank tip end surface 3 to the shank rear end side in the plan view of FIG. From the outer peripheral portion 21 to the opposite side in the circumferential direction, and has a wall surface extending along a direction P1 that forms an acute angle with the shaft center of the shank 1. When viewed in a cross section perpendicular to the extending direction P1, the wall surface is substantially parallel to the rake face 22 at the portion where the tip seat 10 is provided, and a straight line that is at the same or slightly higher position, and the tip seat 10 The portion immediately behind is a concave curved wall surface having a concave arc smoothly connected to the straight line and inclined upward.
In the side view in the front end view of FIG. 5, the front end side pocket 30 opens in the entire region above the rake face 22 in the shank front end surface 3.

  The rear end side pocket 40 which cuts off the shank outer peripheral surface 4b on the opposite side in the circumferential direction of the cutting edge outer peripheral portion 21 is connected to the front end side pocket 30 and further extends to the shank rear end side. Further, the direction P2 extends from the cutting blade outer peripheral portion 21 side toward the opposite side in the circumferential direction of the cutting blade outer peripheral portion 21 as it goes from the shank leading end surface 3 to the shank rear end side, and forms an acute angle with the axial center of the shank 1. Has a wall surface extending along. In consideration of ensuring a sufficient pocket volume, the rear end side pocket 40 has its front end portion biting into the cutting blade outer peripheral portion 21 side from the shaft center of the shank 1 in the side view in the front end view of FIG. In the plan view of FIG. 2, the inclination angle formed by the extending direction P <b> 2 and the axis of the shank 1 is formed to be smaller than the inclination angle of the front-end side pocket 30. The wall surface of the rear end side pocket 40, when viewed in a cross section perpendicular to the extending direction P2, the straight line that is substantially parallel to the rake face 22 at the front end side of the shank and is at the same level or slightly higher, and the rear end side of the shank Then, it is a concave curved wall surface provided with a concave arc smoothly connected to the straight line and inclined upward.

  As shown in the front view of FIG. 3, the sub-pocket 50 that cuts the shank outer peripheral surface 4 a on the cutting blade outer peripheral portion 21 side into a concave curved surface is from the position immediately behind the throw-away tip 20 toward the rear end side of the shank. It extends from the top to the bottom with respect to the rake face 22. 5 is formed on the outer peripheral portion 21 side of the cutting blade from the shaft center of the shank 1, and the volume is smaller than the pockets 30 and 40.

  As shown in FIGS. 1 and 2, a rib that protrudes upward from the rake face 22 between the rear end side pocket 40 and the sub pocket 50 and extends from the front end side of the shank toward the rear end side of the shank. 60 is formed. The rib 60 has a tip portion constituted by a concave curved wall surface of the tip side pocket 30, both side surfaces constituted by a wall surface of the rear end side pocket 40 and a wall surface of the sub pocket 50, and a top surface constituted by a shank outer peripheral surface. Has been.

  According to the boring tool having the above configuration, the shank 1 is moved from the cutting blade outer peripheral portion 21 side toward the opposite side in the circumferential direction of the cutting blade outer peripheral portion 21 as it goes from the shank leading end surface 3 to the shank rear end side. The pockets 30 and 40 extending obliquely with respect to the shaft center accommodate chips generated during cutting, and then guide and discharge the chips along the directions P1 and P2 in which the pockets 30 and 40 extend. Since a larger space is secured between the shank outer peripheral surface 4b and the inner peripheral surface of the inner diameter portion W on the opposite side in the circumferential direction of the cutting blade outer peripheral portion 21 from which chips are discharged, compared to the cutting blade outer peripheral portion 21 side. Since the chips are smoothly discharged without being bitten, a good processed surface can be obtained.

  The chips accommodated in the pockets 30 and 40 are blocked by the ribs 60 and hardly flow to the cutting blade outer peripheral portion 21 side. However, when the auxiliary pocket 50 is provided, a very small number of chips flow to the cutting blade outer peripheral portion 21 side. After the chips are accommodated in the sub-pocket 50, the chips are smoothly discharged without coming into contact with the machining surface, so that the machining accuracy of the inner diameter portion W is further prevented from being deteriorated.

  The pockets 30 and 40 and the sub-pocket 50 are not limited to the boring tool according to the present embodiment, and one or more pockets may be provided. Moreover, in order to improve the induction | guidance | derivation and discharge | emission of the chip in a pocket, it is preferable that each pocket 30 and 40 makes an acute angle with respect to the axial center of the shank 1, and is connected continuously. .

  Further, the rib 60 has a function of suppressing the deterioration of the rigidity of the shank tip 2 cut out in the pockets 30 and 40 and the sub pocket 50. In particular, the rib 60 is raised in the direction in which the main component force acts at the time of cutting, and in order to effectively suppress the reduction in rigidity in this direction, tool chatter is suppressed and deterioration of machining accuracy is prevented.

  As shown in FIG. 2, the rib 60 is preferably formed so as to gradually become wider toward the shank rear end side. This is because the effect of suppressing the deterioration of the rigidity of the shank tip 2 is further increased, and the effect of suppressing the deterioration of tool chatter and preventing the deterioration of machining accuracy is further increased.

  Next, a boring tool according to a second embodiment of the present invention will be described with reference to FIGS. In these drawings, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The boring tool according to the present embodiment is different in the shape of the throw-away tip 20 from the boring tool according to the first embodiment. The throw-away tip 20 has a substantially rhombic flat plate shape, and a pair of nose R portions forming an acute angle of the rhombus surface is set to 35 °. And, by feeding the tool in a direction inclined at a predetermined angle with respect to the axial direction of the shank 1, a nose R portion protruding to the outer peripheral side of the tool and a pair of side ridge portions connected to the nose R portion are provided. The shape portion of the inner diameter portion W can be copied. Similar to the boring tool according to the first embodiment, two pockets 30 and 40 and one sub pocket 50 are provided, and a rib 60 is formed between the rear end side pocket 40 and the sub pocket 50. .

Further, flow passages 70 and 71 having substantially circular cross sections for introducing a fluid such as cutting oil, air, or mist supplied from the outside and discharging the fluid toward the outer peripheral portion 21 of the cutting blade are provided inside the shank 1. ing. The flow paths 70, 71 are open to the rear end face of the shank and extend to the front end side of the shank along the axial center of the shank 1, and communicate with the front end of the first flow path 70 and the outer periphery of the cutting blade. The second flow path 71 is directed to the section 21.
The second flow path 71 is preferably continuous with the constraining surface 12 of the chip seat 10 and opens to the standing surface 13 extending upward from the rake surface 22. This is because the opening of the second flow path 71 is provided close to the outer peripheral portion 21 of the cutting blade, and the fluid can be concentrated and supplied.

The boring tool described above has the same effect as the boring tool according to the first embodiment, and in addition, the opening of the second flow path 71 is brought close to the outer peripheral portion 21 of the cutting edge. Since the fluid is supplied in a concentrated manner, the generated chips are actively removed from the outer peripheral portion 21 of the cutting blade and the vicinity thereof, and the chips 30 and 40 are guided to the pockets 30 and 40. The discharge performance can be further enhanced. For this reason, the effect of suppressing the deterioration of the processing accuracy and the processing surface roughness of the inner diameter portion W becomes remarkable.
In addition, since the second flow path 71 is formed in the rib 60, a decrease in the rigidity of the shank tip 2 is suppressed, so that tool chatter is less likely to occur, and deterioration in processing accuracy and processing surface quality is suppressed. .

  The boring tool of the present invention is not limited to the boring tool according to the embodiment described above. For example, the throw-away tip 20 has a substantially large number represented by a regular triangular plate shape, a rhombus plate shape, and the like. Any square plate or substantially circular plate shape may be used, and the positive chip may be changed to a negative chip. The means for fixing the throw-away tip 20 to the shank tip 2 is not limited to the screw-on method using the tightening screw 5, but for example, a clamp-on method, a lever lock method, a cam lock (also referred to as an eccentric pin clamp) method, or the like. It is possible to appropriately change to at least one fixing means selected from those known. It goes without saying that other configurations can be changed and added without departing from the scope of the present invention.

It is a perspective view of the boring tool which concerns on 1st Embodiment of this invention. It is a top view of the boring tool which concerns on 1st Embodiment of this invention. It is a front view of the boring tool which concerns on 1st Embodiment of this invention. It is a bottom view of the boring tool concerning a 1st embodiment of the present invention. It is a front view side view of the boring tool concerning a 1st embodiment of the present invention. It is a perspective view of the boring tool which concerns on 2nd Embodiment of this invention. It is a top view of the boring tool which concerns on 2nd Embodiment of this invention. It is a front view of the boring tool which concerns on 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shank 2 Shank front-end | tip part 4a Shank outer peripheral surface 4b located in the cutting-blade outer peripheral part side Shank outer peripheral surface 10 located in the circumferential direction opposite side of a cutting-blade outer peripheral part 10 Tip seat 13 Standing surface 20 Throw away tip 21 Cutting-blade outer peripheral part 22 rake face 23 flank face 30 front end side pocket 40 rear end side pocket 50 sub pocket 60 rib 70 first flow path 71 second flow path F tool feed direction P1 front end side pocket extending direction P2 rear end side pocket extending direction W Internal diameter of work material

Claims (3)

The shank tip (2) provided at the tip of the shank (1) having a substantially rod shape is provided with a tip seat (10) consisting of a notch step, and the tip seat (10) is provided with a cutting blade. The throwaway tip (20) is detachably mounted, and the inner peripheral surface of the inner diameter portion (W) of the work material is cut by the outer peripheral portion (21) located on the outer peripheral side of the tool and responsible for cutting. In the boring tool to
The shank tip (2) has a cutting blade outer peripheral portion (21) from the cutting blade outer peripheral portion (21) side as viewed from the rake face (22) side toward the shank rear end side in a plan view. At least one pocket (30, 40) extending in the circumferentially opposite direction and having an extending direction (P) inclined with respect to the axis of the shank (1),
A rib (60) adjacent to the pocket (30, 40) and protruding upward from the rake face (22) extends from the shank tip side toward the shank rear end side. Boring tool.   The boring tool according to claim 1, wherein the rib (60) is formed so as to gradually increase in width from the front end side of the shank to the rear end side of the shank. In the shank (1), there is provided at least one flow path (71) directed to the outer periphery (21) of the cutting edge,
The boring tool according to claim 1 or 2, characterized in that the flow path (71) is formed in the inside of the rib (60) at the shank tip (2).

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