JP2008114308A - Rotary cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary cutting tool capable of achieving great improvement of chip discharging performance and excellent in practicability. <P>SOLUTION: This rotary cutting tool is constituted so that a plurality of spiral chip discharging grooves 2 directing toward the base end side from a tool tip end are formed on an outer periphery of a tool body 1, an outer peripheral edge 3 is formed on an intersection crest line part of a rake face of this chip discharging groove 2 and an outer peripheral surface of the tool body or an outer peripheral flank formed on the outer periphery of the tool body and a plurality of chip breakers 4 recessedly provided on this outer peripheral edge 3 and capable of breaking chips are provided in parallel along a prescribed spiral rotating direction, and the chip breakers 4 are provided in parallel along the spiral rotating direction where the chips moving to the adjacent chip discharging groove 2 on the rear side in the tool rotating direction through the chip breakers 4 from the chip discharging grooves 2 are guided in the same direction as the chip discharging direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotary cutting tool.

  As disclosed in, for example, Patent Document 1, as a rotary cutting tool such as a router used for outer shape processing of a printed wiring board or an end mill used for processing metal materials, the tool tip 21 has a base end on the outer periphery of the tool body 21. A plurality of spiral chip discharge grooves 22 directed to the side are formed, and an outer peripheral blade 23 is formed at a cross ridge line portion between the rake face of the chip discharge groove 22 and the outer peripheral surface of the tool body 21, and the outer peripheral blade 23 A plurality of chip breakers 24 that are recessed and can cut off chips are arranged in parallel along a predetermined spiral rotation direction (see FIG. 1). In the figure, reference numeral 25 is a bottom blade, α ′ is an angle representing the spiral rotation direction of the outer peripheral blade 23, and β ′ is an angle representing the spiral rotation direction as the juxtaposed direction of the chip breakers 24.

  In such a rotary cutting tool, the tool body 21 is rotated by an appropriate rotating means and brought into contact with the workpiece, whereby the workpiece is cut by the outer peripheral edge 23 and the workpiece is cut by the cutting. Chips separated from the object can be discharged from above (or below) the tool while being cut by the chip breaker 24. By cutting the chips, the chips can be discharged more efficiently and the tool life can be extended. ing.

JP 2002-337016 A

  2 and 3, the chip breaker 24 cuts the chips that have been cut by the outer peripheral blade 23 and moved upward (or downward) by the chip discharge groove 22 through the chip breaker 24. While moving to the adjacent chip discharge groove 22 on the rear side in the rotational direction R ′, the chip is divided by contacting the inner surface of the chip breaker 24 during the movement. The conventional chip breaker 24 has been found to have the following problems.

  That is, in a conventional rotary cutting tool that discharges chips from above, for example, chips are guided upward (A ′ direction) from the spiral chip discharge groove 22, whereas a chip breaker is used. Chips moving to the adjacent chip discharge groove 22 via 24 are guided downward (B ′ direction) by the chip breaker 24.

  Therefore, the chip discharging performance upward by the chip discharging groove 22 is partially offset by the chips guided downward through the chip breaker 24, and chip clogging is likely to occur. When chip clogging occurs, it leads to an increase in cutting resistance due to chip welding to the work piece or tool rake face, and an increase in cutting temperature due to a decrease in heat dissipation, resulting in premature tool breakage.

  That is, in the conventional rotary cutting tool disclosed in Patent Document 1, a chip breaker capable of cutting off chips is provided, but a drastically long service life as expected can still be achieved. The current situation is not.

  The present invention has been made in view of the situation as described above, and by arranging chip breakers in parallel in a direction in which chips can be guided in the same direction as chip discharge by the chip discharge grooves, the chip discharge grooves The chip discharge is not hindered by the chip moving to the adjacent chip discharge groove through the chip breaker, and the chip discharge performance can be dramatically improved. A rotary cutting tool is provided.

  The gist of the present invention will be described with reference to the accompanying drawings.

  A plurality of spiral chip discharge grooves 2 are formed on the outer periphery of the tool main body 1 from the tool front end to the base end side. The rake face of the chip discharge groove 2 and the outer peripheral surface of the tool main body or the outer periphery of the tool main body. A plurality of chip breakers 4 that are recessed in the outer peripheral blade 3 and can cut off chips are arranged in parallel along a predetermined spiral rotation direction. In the rotary cutting tool, the chip breaker 4 has chips that move from the chip discharge groove 2 to the adjacent chip discharge groove 2 on the rear side in the tool rotation direction via the chip breaker 4. The present invention relates to a rotary cutting tool characterized by being arranged in parallel along a spiral rotation direction guided in the same direction as a chip discharging direction.

  Further, in the rotary cutting tool according to claim 1, the spiral rotation direction of the chip discharge groove 2 and the spiral rotation direction as the juxtaposition direction of the chip breaker 4 are set in the same direction. This relates to a rotary cutting tool.

  Further, in the rotary cutting tool according to any one of claims 1 and 2, an angle β representing a spiral rotation direction as a juxtaposition direction of the chip breakers 4 with respect to a rotation axis and a spiral rotation of the outer peripheral blade 3 The present invention relates to a rotary cutting tool characterized in that an angle difference with an angle α representing a direction is set to 30 ° or more.

  Since the present invention is configured as described above, chip discharge by the chip discharge groove is not hindered by chips moving to the adjacent chip discharge groove via the chip breaker, and chip discharge performance. It is a rotary cutting tool with excellent practicality that can dramatically improve the tool.

  An embodiment of the present invention which is considered to be suitable will be briefly described with reference to the drawings showing the operation of the present invention.

  The outer peripheral edge 3 of the rotating tool body 1 is brought into contact with the workpiece to cut the workpiece. The chips generated at this time are moved in a predetermined direction (upward or downward) by the chip discharge groove 2 and a part thereof passes through the chip breaker 4 to the adjacent chip discharge groove 2 on the rear side in the tool rotation direction. However, the chips moving through the chip breaker 4 are guided in the same direction as the chip discharge direction by the chip discharge groove 2 by the chip breaker 4. Does not hinder emissions. Therefore, according to the present invention, there is no problem of the chip discharge performance reduction of the chip discharge groove caused by providing the chip breaker, and the chip discharge performance can be greatly improved as compared with the conventional one.

  Specific embodiments of the present invention will be described with reference to FIGS.

  In the present embodiment, a plurality of spiral chip discharge grooves 2 extending from the tool tip to the base end side are formed on the outer periphery of the tool body 1, and the rake face of the chip discharge groove 2 and the outer peripheral surface of the tool body 1. Alternatively, the outer peripheral blade 3 is formed at the intersection ridge line portion with the outer peripheral flank formed on the outer periphery of the tool main body (that is, the outer peripheral blade 3 is formed in a spiral shape), and the outer peripheral blade 3 is recessed to remove chips. A plurality of chip breakers 4 that can be divided are rotary cutting tools arranged in parallel along a predetermined spiral rotation direction, and the chip breaker 4 rotates the tool from the chip discharge groove 2 via the chip breaker 4. Chips moving to the adjacent chip discharge groove 2 on the rear side in the direction are arranged side by side along a spiral rotation direction guided in the same direction as the chip discharge direction by the chip discharge groove 2. is there.

  Specifically, as shown in FIG. 4, the bottom end 8 is provided at the front end and the shank portion connected to the tool mounting portion of the printed wiring board outline processing machine is provided at the base end for the printed wiring board. This is a router that is attached to an outline processing machine and performs cutting such as slotting and outline processing on a printed wiring board, etc., while rotating the tool body 1 in the direction of the right-handed screw, mainly in the downward direction (perpendicular to the rotation axis). It is configured to move the workpiece to be cut and to discharge chips from above the tool.

  In addition, you may apply not only to a router but to other rotary cutting tools, such as an end mill. Moreover, it is good also as other structures, such as the structure which rotates the tool main body 1 in the left-handed screw direction, or performs the cutting | discharging of a chip from the tool lower part.

  Each part will be specifically described.

  The spiral rotation direction as the juxtaposition direction of the chip discharge groove 2 and the chip breaker 4 is set in the same direction. Specifically, it is set in a clockwise spiral shape (so-called right twist) from the tool tip to the tool base side with respect to the tool rotation axis.

  Here, “the same direction” means “a tool when the discharge direction of the chips discharged by the chip discharge groove or the chip breaker is disassembled into the tool rotation axis direction and the tool rotation direction orthogonal to the tool rotation axis direction. The direction of the rotation axis direction component (upper or lower) is the same.

  That is, the chip breaker 4 of the present embodiment forms the chip breaker 4 (for example, grinding formation) after forming the helical chip discharge groove 2 and the outer peripheral blade 3 on the tool body 1 with an appropriate tool (for example, a grindstone). A possible tool (for example, a grindstone) is moved from the distal end side to the proximal end side of the tool main body 1 while rotating the tool main body 1 counterclockwise in the tool front end view, and a part of the outer peripheral blade 3 is removed (for example, It can be formed by grinding and removing).

  Accordingly, the chips cut out from the workpiece by the outer peripheral edge 3 receive an upward force A from the chip discharge groove 2 along with the rotation of the tool body 1, and at the rear in the tool rotation direction R through the chip breaker 4. When moving to the adjacent chip discharge groove 2 on the side, the chip breaker 4 guides to the upper side (direction B) which is the same direction as the chip discharge direction by the chip discharge groove 2.

  Therefore, clogging is unlikely to occur at the portion where the chips moving through the chip discharge groove 2 and the chips entering through the chip breaker 4 join together, and the chips move smoothly upward (E direction) as the discharge direction. Will be.

  That is, in this embodiment, by matching the spiral rotation direction as the juxtaposition direction of the chip discharge groove 2 and the chip breaker 4, the flow of the chips guided and discharged by the chip discharge groove 2 is as follows. By adjusting the guide direction of the chips to the adjacent chip discharge groove 2 by the chip breaker 4, the chips guided by the chip breaker 4 do not obstruct the chips guided by the chip discharge groove 2. Thus, the chip discharge performance by the chip discharge groove 2 can be maintained.

  In this regard, in the conventional configuration, as illustrated in FIGS. 1 to 3, the chips guided by the chip breaker 24 are downward (B ′ direction) opposite to the upper direction (E ′ direction) as the discharge direction. Therefore, the movement of the chips guided upward (A ′ direction) by the chip discharge groove 22 is obstructed, and the discharge ability of the chip discharge groove 22 is reduced, so that the chip breaker 24 is provided. There were few benefits.

  In addition, an angle β (twist angle of the chip breaker) representing the direction of spiral rotation as a juxtaposition direction of the chip breakers 4 with respect to the rotation axis and an angle α (twist of the outer peripheral blade 3) representing the spiral rotation direction of the outer peripheral blade 3 The angle difference from the (twist angle) is set to 30 ° or more. This is because the larger the difference between the twist angle of the outer peripheral blade and the twist angle of the chip breaker, the greater the thickness of the outer peripheral blade 3 on the rear side in the rotation direction, and the strength of the outer peripheral blade 3 is remarkably improved. It is because it is obtained.

  The chip breaker 4 is set to have a concave groove shape in a cross-sectional view, and each chip breaker 4 is provided on the outer peripheral blade 3 in a state inclined toward the upper right in FIG.

  Further, the inner side surface 5 on the tool discharge direction side by the chip discharge groove 2 of the chip breaker 4 is set to an inclined surface inclined with respect to the inner bottom surface 6, and the inner side surface 7 on the opposite side is substantially perpendicular to the inner bottom surface 6. The vertical plane is set. Specifically, as shown in FIG. 8, the inclined surface (inner side surface 5) is 30 ° to 60 ° with respect to the inner bottom surface 6 in a cross-sectional view orthogonal to the spiral rotation direction as the juxtaposed direction of the chip breakers 4. It is good to set it to be tilted by about °. If the angle is set to be less than 30 °, the strength of the corner portion where the outer peripheral edge 3 and the inner side surface 5 intersect increases and the fracture resistance of the outer peripheral edge 3 is improved, but the length of the outer peripheral edge 3 cannot be secured sufficiently and the cutting performance is improved. If the angle exceeds 60 °, chip discharge in the tool discharge direction (upward) will be hindered. In this embodiment, it is set to 45 °. Further, the vertical surface (inner surface 7) does not need to be completely vertical, and may be about 70 ° to 90 ° with respect to the inner bottom surface 6. This is because if the inner side surface 7 is in a nearly vertical state, the cutting load is likely to concentrate on the corner, and the corner is likely to be lost. Further, if the angle is set to less than 70 °, the chips are easily discharged downward, and the upward chip discharge performance deteriorates. In this embodiment, it is set to 80 °. In this embodiment, the inner bottom surface 6 and the inner side surface 7 are connected by a curved surface. Thereby, the chips are more smoothly discharged upward without being accumulated at the corner where the inner bottom surface 6 and the inner surface 7 intersect, and a preferable state is obtained.

  Therefore, during rotary cutting, the chips passing through the chip breaker 4 receive a force in the B direction, and the chips easily pass through the chip breaker 4 and can be cut without increasing the cutting resistance. Become.

  Since the present embodiment is configured as described above, chips generated when the outer peripheral blade 3 of the rotating tool body 1 is brought into contact with the workpiece to cut the workpiece are moved upward by the chip discharge groove 2. Is moved to the adjacent chip discharge groove 2 on the rear side in the tool rotation direction via the chip breaker 4, and the chips moving via the chip breaker 4 are transferred to the chip breaker 4. Therefore, it is guided in the same direction as the chip discharge direction by the chip discharge groove 2, so that the chip discharge by the chip discharge groove 2 is not hindered.

  Therefore, in this embodiment, there is no problem of the chip discharge performance of the chip discharge groove caused by providing the chip breaker, and the chip discharge performance can be drastically improved as compared with the prior art.

  In order to support the effect of this example, experimental examples performed for the following characteristics will be described.

<Chip discharge property>
In each of the present embodiment and the conventional example, the cutting conditions were as follows: rotary cutting tool diameter 1.5 mm, spindle rotation speed 29,000 rpm, feed speed 1.1 m / min (feed speed in the radial direction (tool diameter direction)) As shown in FIG. 9, a Wavy pattern as shown in FIG. 9 was applied to a workpiece to which three heat resistant glass cloth base epoxy resin laminates having a thickness of 1.6 mm were stacked.

  FIG. 10 shows the experimental result of the conventional example, and FIG. 11 shows the experimental result of the present example. In the case of the material processed according to the conventional example, chips are clogged in the processing groove (white area in the photograph), while in the case of the material processed according to this example, clogging of chips was hardly recognized.

<Cutting power>
In each of the present example and the conventional example, the cutting power was measured (at the initial stage of machining). The cutting power is divided into three components (Fx, Fy, Fz) as shown in FIG. 12, where Fx and Fy represent the radial direction and Fz represents the thrust direction.

  FIG. 13 shows the experimental result of the conventional example, and FIG. 14 shows the experimental result of the present example. When both are compared, Fz (thrust direction) is greatly different. Here, since Fz is positive in the vertical downward direction, a negative value means a force by which chips are discharged upward from the workpiece. Therefore, it can be seen from the cutting power that the present embodiment is excellent in chip discharge.

<Fracture life>
Processing was performed until the tool was broken, and the distance to the break was evaluated.

  The experimental results are shown in FIG. It was found that this example was superior in breakage resistance compared to the conventional example. This is because, as can be seen from the above results, the present embodiment has good chip discharge performance, reduced cutting resistance and processing temperature, and a shape that is less prone to chipping of the outer peripheral edge. I think that.

It is a schematic explanatory plan view of a conventional example. It is a schematic explanatory drawing of a prior art example. It is a schematic diagram of the force which a chip receives from the chip discharge groove | channel and chip breaker of a prior art example. It is a description top view of a present Example. It is a schematic explanatory plan view of a present Example. It is a schematic explanatory drawing of a present Example. It is a schematic diagram of the force which a chip receives from the chip discharge groove | channel and chip breaker of a present Example. It is an expansion outline explanatory sectional view orthogonal to the direction of spiral rotation as an arrangement direction of a chip breaker. It is explanatory drawing which shows the wave pattern used for the chip discharge | emission confirmation experiment. It is a photograph which shows the result of the chip discharge | emission confirmation experiment of a prior art example. It is a photograph which shows the result of the chip discharge | emission confirmation experiment of a present Example. It is a schematic explanatory drawing of cutting power confirmation experiment. It is a graph which shows the result of the cutting power confirmation experiment of a prior art example. It is a graph which shows the result of the cutting power confirmation experiment of a present Example. It is a graph which shows the result of a fracture life confirmation experiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tool main body 2 Chip discharge groove 3 Peripheral blade 4 Tip breaker (alpha) The angle showing the helical rotation direction of the outer peripheral blade 3 (beta) The angle showing the helical rotation direction as the juxtaposition direction of the chip breaker 4

Claims (3)

  A plurality of spiral chip discharge grooves are formed on the outer periphery of the tool main body from the tip of the tool toward the base end, and are formed on the rake face of the chip discharge groove and the outer peripheral surface of the tool main body or the outer periphery of the tool main body. An outer peripheral blade is formed at the crossing ridge line portion with the outer peripheral flank, and a plurality of chip breakers that are recessed in the outer peripheral blade and can sever chips are provided by a rotary cutting tool arranged in parallel along a predetermined spiral rotation direction. The chip breaker is guided in the same direction as the chip discharge direction by moving the chip breaker from the chip discharge groove to the adjacent chip discharge groove on the rear side in the tool rotation direction via the chip breaker. A rotary cutting tool, wherein the rotary cutting tools are arranged side by side along a spiral rotation direction.   2. The rotary cutting tool according to claim 1, wherein the spiral rotation direction of the chip discharge groove and the spiral rotation direction as the juxtaposition direction of the chip breaker are set in the same direction.   The rotary cutting tool according to any one of claims 1 and 2, wherein an angle that represents a spiral rotation direction as a parallel arrangement direction of the chip breakers with respect to a rotation axis and an angle that represents a spiral rotation direction of the outer peripheral blade; The rotary cutting tool is characterized in that the angle difference is set to 30 ° or more.

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