JP4961841B2 - Boring tool - Google Patents

Description

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

  In this type of tool, when a sufficient chip pocket volume is secured in order to improve the chip discharge performance, the tool rigidity is deteriorated and tool chatter easily occurs.

  For example, in Patent Document 1, the head portion 3 of the tool body 1 is formed with a concave groove 15 on the outer peripheral surface 3b between the chip pocket 6 and the back portion of the back surface of the chip mounting seat 10, thereby reducing the weight of the head portion 3. Thus, the resonance is suppressed by increasing the natural frequency of the head portion 3 during the cutting process and the deviation from the frequency of the external force received from the workpiece. Further, a rib portion 22A that increases the thickness of this region is formed between the chip pocket 6 and the concave groove 15 to ensure the rigidity of the head portion 3.

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 rib portion 22A is greatly separated from the nose portion 13c in the radial direction, and the deflection of the head portion 3 due to the main component force F1 cannot be sufficiently suppressed. If the rib portion 22A is brought close to the nose portion 13c in the radial direction, the volume of the chip pocket 6 is reduced, which may cause a problem in chip disposal.

  Even in the invention of Patent Document 2, the rib 5 is disposed substantially in the center in the width direction of the holder 7, and the bending of the holder 7 due to the main component force cannot be sufficiently suppressed. If the rib 5 is arranged on the blade edge side in the width direction of the holder, the volume of the first pocket 1 becomes insufficient, and there is a possibility that the chip disposal property is deteriorated.

  The present invention has been made to solve the above problem, and an object thereof is to provide a boring tool capable of suppressing the deterioration of the shank rigidity without impairing the chip discharging performance.

In order to solve the above-mentioned problem, the invention according to 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). ), And a throw-away tip (20) having a cutting edge is detachably mounted on the tip seat (10), and the cutting edge outer peripheral portion (21) is located on the tool outer peripheral side of the cutting blade and performs cutting. In the boring tool that cuts the inner peripheral surface of the inner diameter portion (W) of the work material by the shank, the shank distal end portion (2) has a shank outer peripheral surface (4b) on the opposite side of the cutting blade outer peripheral portion (21) in the circumferential direction. ) And at least one pocket (30, 40) extending from the shank tip side to the shank rear end side, and a rib (60) adjacent to the pocket (30, 40) extends from the shank tip side to the shank rear end. Extended to the side, less Also boring tool, wherein a front end of the rib (60) is biased to the cutting outer peripheral portion than the center (21) side of the shank (1).
According to the boring tool of the present invention, the rib (60) suppresses deterioration of the rigidity of the shank tip (2) from which the pockets (30, 40) are cut, and reduces the deflection of the shank tip (2). , Preventing the processing accuracy from deteriorating.
Since at least the tip of the rib (60) is formed on the side of the cutting blade outer peripheral portion (21) from the center of the shank (1), the cutting force (especially the main component force) acting on the cutting blade outer peripheral portion (21) in particular. The bending of the shank tip (2) is suppressed, and deterioration of processing accuracy is prevented.
On the other hand, the tip of the pocket (30, 40) adjacent to the rib (60) is formed by biting into the outer peripheral portion (21) side of the cutting blade from the center of the shank (1). 30, 40), and after being guided along the pockets (30, 40), the shank outer peripheral surface (4 b) and the inner diameter portion (W) located on the opposite side in the circumferential direction of the cutting blade outer peripheral portion (21) Since it is discharged without being bitten into a relatively large space secured between the inner peripheral surface and the inner peripheral surface, the processing surface is not damaged.

The boring tool according to claim 2, wherein the rib (60) is formed at least on the side of the outer periphery (21) of the cutting blade from the center of the shank (1) over the entire length of the rib (60). The boring tool according to claim 1.
According to the boring tool of the second aspect, it is possible to further reduce the bending of the shank tip (2) due to the cutting resistance and effectively suppress the deterioration of the machining accuracy.

The boring tool according to claim 1 or 2, wherein the rib (60) is formed so as to increase in width from the front end side of the shank to the rear end side of the shank. It is.
According to the boring tool of claim 3, since the effect of suppressing the deterioration of the rigidity of the shank tip (2) becomes extremely large, the bending of the shank tip (2) due to cutting resistance is made extremely small, The deterioration of accuracy can be greatly suppressed.

The boring tool according to claim 4, 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 any one of claims 1 to 3, wherein the boring tool is formed in the inside of the rib (60) in the shank tip (2).
According to the boring tool of claim 4, the cutting blade outer peripheral portion (21) and chips in the vicinity thereof are positively removed by a fluid such as cutting oil, air, or mist, and chip discharge of the pockets 30 and 40 is promoted. In addition, since the flow path (71) is drilled in the rib (60), the bending of the shank tip (2) is reduced in order to suppress the deterioration of the rigidity of the shank tip (2). Prevent deterioration of accuracy.

According to the boring tool of the present invention, the rib (60) suppresses deterioration of the rigidity of the shank tip (2) from which the pockets (30, 40) are cut, and reduces the deflection of the shank tip (2). , Preventing the processing accuracy from deteriorating.
Since at least the tip of the rib (60) is formed on the side of the cutting blade outer peripheral portion (21) from the center of the shank (1), the cutting force (especially the main component force) acting on the cutting blade outer peripheral portion (21) in particular. The bending of the shank tip (2) is suppressed, and deterioration of processing accuracy is prevented.
On the other hand, the tip of the pocket (30, 40) adjacent to the rib (60) is formed by biting into the outer peripheral portion (21) side of the cutting blade from the center of the shank (1). 30, 40), and after being guided along the pockets (30, 40), the shank outer peripheral surface (4 b) and the inner diameter portion (W) located on the opposite side in the circumferential direction of the cutting blade outer peripheral portion (21) Since it is discharged into a relatively large space secured between the inner peripheral surface and the inner peripheral surface, a machined surface having excellent surface roughness with few scratches due to chip biting can be obtained.

The boring tool according to the first embodiment of the present invention will be described below 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 a regular triangular flat plate shape is positioned by seating one triangular 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. Then, it is detachably attached to the chip seat 10 using the tightening screw 5. The throwaway tip 20 has a triangular surface on its upper surface as a rake face 22, and each apex of the triangular surface includes a 60 ° nose R portion and a pair of side ridge portions extending from the nose R portion. There are three sets of cutting blades, and a flank 23 is formed on the peripheral surface extending from the cutting blade, and the flank 23 is a positive tip inclined inward of the throw-away tip 20. When the throw-away tip 20 is mounted on the tip seat 10, in one of the three sets of cutting blades, a nose R portion and a side ridge disposed so as to protrude from the shank tip surface 3 and the shank outer peripheral surface 4a, respectively. The part is a cutting edge outer peripheral part 21 that cuts the inner peripheral surface of the inner diameter part W.

The shank tip 2 is formed with two pockets 30 and 40 that cut out at least the shank outer peripheral surface 4b located on the opposite side of the cutting blade outer peripheral portion 21 in the circumferential direction.
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. Extends toward the opposite side of the peripheral edge 21 of the cutting blade 21 and extends along a direction P1 that forms an acute angle with the central axis of the shank 1. When viewed in a cross section orthogonal to the extending direction P1, the tip side pocket 30 is a straight line that is substantially parallel to the rake face 22 and is equidistant or slightly higher at the portion where the chip seat 10 is provided. A portion on the rear side of the seat 10 is provided with a concave curved wall surface that is smoothly connected to the straight line and is inclined upward.
Further, 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 continuously formed on the rear end side of the front end side pocket 30 is a circumferential direction from the cutting blade outer peripheral portion 21 side to the cutting blade outer peripheral portion 21 as it goes from the shank front end surface 3 to the shank rear end side. It extends toward the opposite side and extends along a direction P2 that forms an acute angle with the central axis of the shank 1. In consideration of ensuring a sufficient pocket volume of the rear end side pocket 40, the front end portion of the rear end side pocket 40 bites into the cutting blade outer peripheral portion 21 side from the center of the shank 1 in the side view in the front end view of FIG. In the plan view of FIG. 2, the angle formed by the extending direction P <b> 2 and the central axis of the shank 1 is formed so as to be smaller than the tip side pocket 30. The rear end side pocket 40, when viewed in a cross section orthogonal to the extending direction P2, is a straight line that is substantially parallel to the rake face 22 at the tip end side of the shank and is at the same or slightly higher position, and at the rear end side of the shank. It has a concave curved wall surface that is smoothly connected to the straight line and has a concave arc shape that is inclined upward.

  On the other hand, a sub-pocket 50 is formed in the shank outer peripheral surface 4a located on the cutting blade outer peripheral portion 21 side to cut out the shank outer peripheral surface 4a into a concave curved surface. As shown in the front view of FIG. 3, the secondary pocket 50 extends from the position immediately behind the throw-away tip 20 toward the rear end of the shank, and is formed from above to below the rake face 22. Yes. 5 is formed only on the outer peripheral portion 21 side of the cutting blade from the center of the shank 1, and the volume is considerably smaller than the pockets 30 and 40.

  As shown in FIGS. 1 and 2, between the rear end side pocket 40 and the sub pocket 50, the rake face 22 protrudes upward and extends from the shank tip side toward the shank rear end side. A rib 60 of the strip is formed. The front end portion of the rib 60 is formed by a concave curved wall surface of the front end side pocket 30, both side surfaces are formed by concave curved wall surfaces of the rear end side pocket 40 and the sub pocket 50, and the top surface is the outer peripheral surface of the shank. It consists of As described above, the tip end portion of the rear end side pocket 30 is formed so as to bite into the cutting blade outer peripheral portion 21 side from the center of the shank 1, so that the tip portion of the rib 60 extends from the center of the shank 1 to the cutting edge outer periphery. It is formed biased toward the portion 21 side.

According to the boring tool having the above configuration, the ribs 60 extending upward from the rake face 22 and extending from the shank tip side toward the shank rear end side have the pockets 30 and 40 and the sub pocket 50 cut away. The rigidity of the shank tip 2 is suppressed, the deflection of the shank tip 2 is reduced, and the processing accuracy is prevented from deteriorating.
Since the tip end portion of the rib 60 is formed so as to be biased toward the cutting edge outer peripheral portion 21 side from the center of the shank 1, it acts downward on the cutting blade outer peripheral portion 21 in a position biased from the center of the shank 1 to the outer peripheral side. The bending of the shank tip 2 due to the main component force is suppressed, and tool chatter and deterioration of machining accuracy are prevented.

  On the other hand, since the tip portions of the pockets 30 and 40 adjacent to the rib 60 are formed by biting into the cutting blade outer peripheral portion 21 side from the center of the shank 1, a pocket volume sufficient to accommodate chips is secured. At the same time, it is discharged along the pockets 30 and 40 to the rear end side of the shank and to the opposite side in the circumferential direction of the outer peripheral portion 21 of the cutting blade. The chips are accommodated in the pockets 30 and 40 and guided along the pockets 30 and 40, and then the shank outer peripheral surface 4b located on the opposite side in the circumferential direction of the cutting blade outer peripheral portion 21 and the inner peripheral surface of the inner diameter portion W. Since it is discharged without being bitten into a relatively large space secured between the two, the processing surface is not damaged.

In the boring tool according to the present embodiment, as shown in FIG. 2, the rib 60 extends to the rear end portion of the shank, and the outer periphery of the cutting blade is at least from the center of the shank 1 over the entire extending length. When formed on the portion 21 side, the deterioration of rigidity is suppressed over the entire shank tip 2, and in particular, the effect of suppressing the deflection due to the main component force occurs over the entire shank tip 2, so that tool chatter and machining accuracy are deteriorated. The effect of preventing is further increased.
Further, when the rib 60 is formed so as to gradually become wider toward the shank rear end side, the deterioration of rigidity is suppressed toward the rear end side of the shank front end portion 2, so that the deflection of the shank front end portion 2 is suppressed. The tool chatter and the deterioration of machining accuracy are greatly suppressed.

A pocket 30 extending obliquely with respect to the axial center of the shank 1 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. , 40 accommodates chips generated during cutting and then guides and discharges the chips along the directions P1, P2 in which the pockets 30, 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 discharged without being bitten, a processed surface with few scratches and excellent surface roughness can be obtained.
The chips accommodated in the pockets 30 and 40 are blocked by the rib 60 and hardly move to the cutting blade outer peripheral portion 21 side, but a small number of chips flowing to the cutting blade outer peripheral portion 21 side are accommodated in the sub pocket 50. After that, since it is smoothly discharged without contacting the processed surface, deterioration of the processing accuracy of the inner diameter portion W is suppressed.

  The pockets 30 and 40 are not limited to the boring tool according to the present embodiment, and one or more or two or more pockets may be provided. Further, in order to improve the induction and discharge of chips in the pockets 30 and 40, the extending directions of the pockets 30 and 40 form an acute angle with respect to the central axis of the shank 1 and are continuously connected. Is preferred.

  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 of the boring tool according to 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 rhomboid flat plate shape, and a pair of nose R portions forming an acute angle of the rhombus surface is set to 35 °. And by giving a tool feed in the direction inclined at a predetermined angle with respect to the central axis 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. The shank tip 2 is provided with two pockets 30, 40, and ribs 60 are formed between the pockets 30, 40 and the outer peripheral surface 4 a located on the cutting blade outer peripheral portion 21 side. Similarly to the boring tool according to the first embodiment, the rib 60 is formed such that the tip end thereof is biased toward the cutting edge outer peripheral portion 21 side from the center of the shank 1, and at least over the entire length of the shank 1 in the central axis direction. It is formed on the outer peripheral portion 21 side of the cutting edge from the center, and is formed so as to gradually widen toward the rear end side of the shank.

  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 passages 70, 71 are open to the rear end face of the shank and extend to the front end side of the shank along the central axis of the shank 1, and communicate with the tip end portion of the first flow passage 70 and the tip seat 10. The second flow path 71 is opened to a standing surface 13 extending upward from the restraining surface 12 and directed to the outer peripheral portion 21 of the cutting blade. Further, the second flow path 71 is formed inside the rib 60.

The boring tool described above has the same function and effect as the boring tool according to the first embodiment, and positively removes the cutting blade outer peripheral portion 21 and chips in the vicinity thereof by the fluid. Since the chip discharge of 30 and 40 is promoted and the chip biting is prevented, the surface roughness of the processed surface is improved.
Moreover, since the second flow path 71 is provided in the rib 60, the deterioration of the rigidity of the shank tip 2 is suppressed, so that the deflection of the shank tip 2 is reduced and the processing accuracy is prevented from being deteriorated.

  The boring tool of the present invention is not limited to the boring tool according to the above-described embodiment. For example, the throw-away tip 20 is not limited to an equilateral triangular plate shape or a rhombus plate shape, and is substantially numerous. It may be a square plate or a substantially circular plate, and the positive chip may be changed to a negative chip. Further, 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 3 Shank front-end | tip surface 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 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 P1 front end side pocket extending direction P2 rear end side pocket extending direction W Inner diameter

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 front end (2) has a shank outer peripheral surface (4b) on the opposite side in the circumferential direction of the cutting blade outer peripheral portion (21), and at least one pocket ( 40 ) extends from the shank front end side to the shank rear end side. Extended over,
A rib (60) adjacent to the pocket ( 40 ) extends from the front end side of the shank toward the rear end side of the shank;
At least the tip portion of the rib (60) is biased to the cutting edge peripheral portion (21) side than the center of the shank (1),
Inside the shank (1) is provided at least one flow path (71) of fluid directed to the outer peripheral portion (21) of the cutting edge, and the flow path (71) is provided in the shank tip (2). Drilled inside the rib (60),
A sub-pocket (50) is provided on the outer peripheral portion (21) side of the shank (1), and the sub-pocket is located on the rear end side of the shank from a position continuous or adjacent to the throw-away tip (20). Toward the concave surface and from the top to the bottom of the rake face (22) of the throw-away tip (20),
A boring tool characterized in that the volume of the sub-pocket (50) is smaller than the volume of the pocket (40) .   The rib (60) is characterized in that at least a part of the rib (60) is formed on the cutting blade outer peripheral part (21) side from the center of the shank (1) over the entire extending length. Boring tool. The boring tool according to claim 1 or 2, characterized in that the rib (60) is formed wider as it goes from the front end side of the shank to the rear end side of the shank.

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