JP6069791B2 - Cutting tool and cutting apparatus equipped with this cutting tool - Google Patents

Description

  The present invention relates to a small-sized cutting tool capable of smoothly and accurately performing processing such as chamfering and deburring of a back surface of a workpiece, and a cutting apparatus including the cutting tool.

  Conventionally, a cutting tool such as a drill or an end mill is used for drilling a metal workpiece. In addition, these cutting tools are used by being attached to a cutting machine such as a drilling machine, an NC (Numerical Control) lathe, or a machining center. When drilling a workpiece using these cutting tools, cutting is performed from one surface of the workpiece, for example, the surface on the front side placed on a lathe, and the cutting tool is moved to the other surface of the workpiece. This is done by penetrating the cutting tool to a surface, for example, the back surface.

  At this time, when the cutting tool penetrates through the hole on the back surface of the workpiece, a burr may be formed around the hole, so that the burr needs to be removed. In addition, there are corners around the holes that are formed, and if touched by an operator or user, injury may occur or other parts may be damaged. Chamfering is performed. As described above, when drilling is performed, it is necessary to perform processing on the back side of the work piece. However, it is troublesome to turn over the work pieces one by one and process again, and workability is poor. Become. Therefore, a cutting tool that can process the back surface of the workpiece has been desired.

  In order to perform such processing on the back side of the workpiece, the following Patent Document 1 discloses a double-sided chamfering drill that enables a drilling operation, a front surface chamfering operation, and a back surface chamfering operation with a single drill. Is disclosed. In the invention of the double-sided drill disclosed in Patent Document 1 below, a drill body connected to the shank, a cutting edge at the tip of the drill body, and a part of the shank, the drill body and the cutting edge, And a relief groove that is notched in parallel with the axis, and a front drill blade having an inclination angle of about 90 degrees constituting the cutting blade is formed so as to be gently inclined from the tip of the drill, In the double-sided drill in which an outer diameter blade is formed above and a chamfering blade of about 45 degrees is formed with respect to the outer diameter blade that is inclined from the outer diameter blade to the drill body or with a steep angle, the outer diameter blade However, the first width is extremely narrow and gradually widened from one escape groove to the other.

  According to the invention of the double-sided chamfer disclosed in Patent Document 1 below, a drilling operation, a chamfering operation of a workpiece, a chamfering operation of a back surface, and a chamfering operation of a side surface portion are performed together with a front drill blade and an outer diameter blade. It is said that it has the excellent advantage that four tasks can be processed simultaneously.

JP 2000-288813 A

  In the invention of the double-sided drill disclosed in Patent Document 1, the chamfering blade for chamfering the back surface of the hole is formed substantially perpendicular to the axis of the drill. In this way, when chamfering is performed with a chamfering blade formed substantially vertically, cutting is performed perpendicularly to the part to be processed of the workpiece, so that a large force is applied to the part to be cut from a right angle direction. There is a risk of damage. In addition, when used for deburring, there is a possibility that a new burr may be generated by being pulled almost directly when deburring.

  It is also conceivable to form a twist on the cutting edge like a conventional drill or end mill. However, in general, a twist suitable for drilling is used in the same direction with respect to the rotation direction of the cutting tool. That is, it is because it becomes easy to discharge the waste cut at the time of drilling along the groove | channel formed with a cutting blade. Therefore, when forming a chamfering blade for chamfering the back surface as an extension of the cutting blade for drilling, it is formed by twisting in the same direction as the rotation direction of the cutting tool. And if chamfering of the back surface is performed using a chamfering blade in which a twist in the same direction as the rotation direction of the cutting tool is formed, the cut scraps are discharged upward, that is, toward the workpiece. It becomes difficult to perform chamfering and deburring smoothly.

  The present inventor has conducted various experiments in view of the problems of the prior art and the problems to be solved, and as a result, the groove and the cutting edge formed in the cutting portion of the cutting tool are opposite to the rotation direction of the cutting tool. As a result, it has been found that deburring and chamfering can be performed smoothly, and the present invention has been completed.

  That is, an object of the present invention is to provide a small cutting tool capable of smoothly deburring and chamfering the back surface of a workpiece and a cutting apparatus including the cutting tool.

In order to solve the above problems, a cutting tool according to a first aspect of the present invention is inserted from one side of a through hole formed in a workpiece, and the through hole on the other side surface of the workpiece is inserted. A cutting tool having a blade portion that is processed while rotating around, and a neck portion having an outer diameter smaller than the outer diameter of the blade portion connected to the blade portion,
On the neck side of the blade part, a cutting part for processing the periphery of the through hole in the other surface of the workpiece is formed so as to be inclined at a predetermined angle with respect to the rotation axis .
The cutting part has at least one groove twisted in a direction opposite to the rotating direction, and a cutting edge along the groove on the outer peripheral side of the cutting part. .

  The cutting tool according to the second aspect is characterized in that, in the cutting tool according to the first aspect, the diameter of the blade portion is formed in a range of 0.5 mm or more and 6.0 mm or less.

  Further, the cutting tool of the third aspect is characterized in that in the cutting tool of the first or second aspect, the diameter of the blade portion is formed to be 2 to 3 times the diameter of the neck portion. To do.

Further, the cutting tool of the fourth aspect is the cutting tool of any one of the first to third aspects, wherein a thread is formed in the through hole.
The height of the thread is smaller than a distance that is half the difference between the diameter of the blade and the diameter of the neck .

  Moreover, the cutting tool according to the fifth aspect is the cutting tool according to any one of the first to fourth aspects, wherein the cutting portion has an inclination of 30 ° or more and 60 ° or less with respect to the rotation axis. It is formed.

The cutting tool of the sixth aspect is the cutting tool of any one of the first to fifth aspects, wherein the neck is connected to a shank formed with an outer diameter larger than the outer diameter of the neck. ,
The connecting portion between the shank and the neck portion has a tapered portion formed by gradually reducing the diameter from the shank toward the neck portion.

  A cutting device according to a seventh aspect includes the cutting tool according to any one of the first to sixth aspects.

  According to the cutting tool of the first aspect, the cutting edge and the groove of the cutting portion are formed by being twisted in the direction opposite to the rotation direction of the cutting tool, thereby smoothly cutting the back surface of the workpiece. Will be able to. For example, when the cutting tool rotates clockwise, the cutting edge and groove are formed with left-handed twist, and conversely, when rotated counterclockwise, the cutting edge and groove are formed with right-handed twist. Become. Then, since the groove and the cutting edge are formed in the opposite direction with respect to the rotation direction, the cut piece of the work piece cut out during the cutting is cut by the cutting edge and the groove having the twist in the direction opposite to the rotation direction. It will be discharged smoothly to the side.

Further, according to the cutting tool of the first aspect, it excised intercept to be discharged to the tip side of the blade section, is suppressed or to scatter adhering intercept the workpiece and the operator, The workability of the cutting work can be improved. Further, according to the cutting tool of the first aspect, since it has a simple structure, the cutting tool can be manufactured easily and at low cost. Incidentally, the through hole is not limited to the hole formed in the straight portion of the hole as such threaded tap hole threaded formed it is also included those processed.

  Moreover, according to the cutting tool of the 2nd and 3rd aspect, also as a cutting tool which has a small blade part and a neck part, the direction of the twist formed in a groove | channel and a cutting blade shall be the direction opposite to a rotation direction. Thus, since the force applied during cutting is reduced, high durability can be obtained, and breakage and damage can be suppressed.

  Further, according to the cutting tool of the fourth aspect, when chamfering or deburring the tap hole in which the thread is formed in the through hole, the blade part and the cutting part of the cutting tool are at the height of the thread. It will be formed in a corresponding size. As a result, even if the cutting tool is miniaturized, it becomes possible to perform chamfering and deburring with the optimum size for the thread formed in the through hole.

  Further, according to the cutting tool of the fifth aspect, it is possible to perform desired processing by selecting the angle of inclination of the cutting portion and making the cutting portion according to the design of the workpiece. In addition, the angle of the cutting part is preferably 30 ° to 60 °, and more preferably 45 °.

  In addition, according to the cutting tool of the sixth aspect, by forming the portion connecting the shank and the neck with a reduced diameter, it becomes possible to withstand the stress applied when pressing against the workpiece during cutting. It becomes possible to suppress the breakage and deformation of the cutting tool. The taper angle is preferably 10 ° to 15 ° with respect to the axis, and more preferably 12 °.

  According to the cutting device of the seventh aspect, it is possible to obtain a cutting device that exhibits the effects of any one of the first to sixth aspects.

It is a side view of the cutting tool concerning an embodiment. It is the side view to which the blade part of the cutting tool concerning an embodiment was expanded. FIG. 3A is a side view illustrating a process of processing the workpiece of the cutting tool according to the embodiment, FIG. 3B is a side view illustrating a process subsequent to FIG. 3A, and FIG. 3C is a state during the process. FIG. 4 is an enlarged view of a part IIIC in FIG. FIG. 4A is a side view showing a processing step subsequent to FIG. 3B, FIG. 4B is a simplified diagram for explaining a cutting process, and FIG. 4C is a side view showing a processing step following FIG. 4A. It is a side view which shows the application example of a cutting tool.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a cutting tool for embodying the technical idea of the present invention and a cutting apparatus including the cutting tool, and is intended to specify the present invention. It is not a thing. The invention is equally applicable to other embodiments within the scope of the claims.

[Embodiment]
With reference to FIG.1 and FIG.2, the cutting tool 10 which concerns on embodiment of this invention is demonstrated. The cutting tool 10 according to the embodiment of the present invention removes burrs formed on the back surface 21 of the through-hole 22 formed on the work piece 19 using a tool such as a drill or an end mill, or removes the corner of the through-hole. Chamfering. The back surface 21 of the work piece 19 is defined as one surface of the work piece 19, that is, the side into which a drill or the like is inserted to form the through-hole 22. The other side of the workpiece 19, that is, the side on which the cutting tool 10 protrudes when the through hole 22 is formed is a back surface 21. Moreover, although the through-hole 22 is demonstrated as a mere hole, it is not restricted to this, It is good also as a tap hole in which the screw thread was formed.

  The workpiece is processed automatically by attaching the cutting tool 10 of the embodiment to a cutting apparatus and using a predetermined program. Examples of such a cutting device include an NC lathe and a machining center. In addition, since such a cutting device is a well-known thing, detailed description is abbreviate | omitted.

  The cutting tool 10 of embodiment is comprised by the shank 11, the neck part 13, and the blade part 14 which were integrally formed by the metal material, as shown in FIG.1 and FIG.2. The shank 11 is formed of a rod-like body having a predetermined length and a predetermined outer diameter, and one side is connected to the neck portion 13 and the other side is a portion attached to the cutting device.

  The neck portion 13 is formed of a rod-like body having a predetermined length and an outer diameter smaller than that of the shank 11 and the blade portion 14, and one side is connected to the blade portion 14 and the other side is connected to the shank 11. The length of the neck portion 13 is related to the thickness of the workpiece 19 to be processed, and is a length that allows the blade portion 14 to contact the back surface 21 of the workpiece 19. Therefore, the length of the neck can be selected according to the workpiece to be processed.

  Moreover, the taper part 12 diameter-reduced so that it may become thin toward the neck part 13 side from the shank 11 side is formed in the part where the shank 11 and the neck part 13 were connected. The angle θ3 of the taper portion 12 with respect to the axis is formed to be about 10 ° to 15 °, and particularly preferably 12 °. Thus, by providing the taper part 12, the part which the shank 11 and the neck part 13 were connected can be strengthened, and it can suppress that it is damaged or broken by the stress applied at the time of cutting.

  The blade portion 14 is formed of a rod-like body having a predetermined length and an outer diameter larger than that of the neck portion 13, and one end is a tip portion 15 and the other side is connected to the neck portion 13. The blade portion 14 is formed with a plurality of grooves 16, in the embodiment, three grooves 16. These grooves 16 are formed by twisting in a direction opposite to the direction in which the cutting tool 10 rotates. That is, when the cutting tool 10 rotates to the right, the twist direction is formed by left-handed twist. Further, when the cutting tool rotates counterclockwise, the direction of twist is formed by right twist. In addition, in the cutting tool 10 of embodiment, in order to demonstrate the case where it rotates to the right, the direction of twist is formed by left twist.

  A cutting edge 17 is formed along the groove 16 on the outer peripheral side of the blade portion 14. Since the cutting blades 17 are formed corresponding to the number of the grooves 16, three cutting blades are formed in the embodiment. The blade portion 14 on the neck 13 side is formed with a cutting portion 18 that presses against a portion of the workpiece 19 to be processed and performs cutting. The cutting portion 18 is formed by inclining the cutting edge 17 at a predetermined angle θ1. This angle θ1 is formed at 45 ° with respect to the axis of the cutting tool. The angle θ1 can be an angle at which the workpiece is processed, and is not limited to 45 °, and can be formed at an arbitrary angle.

  Further, the tip portion 15 side of the blade portion 14 is formed to be inclined at an angle θ2. By forming the tip portion 15 so as to be inclined in this manner, the tip portion 15 can be easily inserted into a through-hole formed in the workpiece, and damage to the surface of the workpiece can be suppressed. In addition, although this inclination is formed at 45 degrees, it is not restricted to this, It can form at arbitrary angles.

  In the cutting tool 10 of the embodiment, the diameter D1 of the blade portion 14 is formed with a very small diameter, for example, a diameter of 0.5 mm. At this time, according to the diameter D1 of the blade part 14, the diameter of the neck part 13 is also formed with a smaller diameter. That is, the diameter D2 of the neck 13 is formed to be approximately 1/3 to 1/2 of the diameter D1 of the blade 14. In other words, the diameter of the blade portion 14 is formed to be about twice to three times the size of the diameter D2 of the neck portion 13.

  Thus, the blade part 14 and the neck part 13 can be formed in a very small size because the groove 16 and the cutting edge 17 formed in the blade part 14 are twisted in the direction opposite to the rotation direction. This is because the force generated during cutting is reduced compared to the case of the conventional example. Therefore, the blade part and the neck part are hardly damaged, and high durability can be obtained even if the blade part and the neck part are ultra-compact. The diameter D1 of the blade portion is not limited to 0.5 mm, and may be 0.5 mm or more, but is preferably formed with a size of 6.0 mm or less.

  Next, with reference to FIG.3 and FIG.4, the process of the cutting tool 10 of embodiment is demonstrated. 3 and 4, the workpiece 19 is shown in a cross-sectional view for explanation.

  First, as a premise of performing processing with the cutting tool 10 of the embodiment, as shown in FIG. 3A, a through hole is formed in the workpiece 19 by a drill, an end mill, or the like in advance. The diameter of the through hole 22 is larger than the diameter of the blade portion 14 of the cutting tool 10 of the embodiment.

  As shown in FIG. 3A, the cutting tool 10 of the embodiment is inserted from the through hole 22 of the surface 20 of the workpiece 19 so that the cutting portion 18 of the blade portion 14 corresponds to the portion of the workpiece 19 to be processed. Deploy. Thereafter, as shown in FIG. 3B, the cutting tool 18 rotates to the right, and the cutting portion 18 of the cutting tool 10 comes into contact with a portion around the through hole 22 to be processed on the back surface 21 of the workpiece 19, thereby processing the workpiece. The object 19 is cut. At this time, as shown in FIG. 3C, the scrap 23 obtained by cutting the workpiece 19 passes through the left-twisted groove 16 formed in the blade portion 14 and is discharged to the lower side of the workpiece 19.

  Then, as shown in FIGS. 4A and 4B, the cutting tool 10 is caused to make at least one turn along the outer periphery of the through hole 22, and processing around the back surface 21 side of the through hole 22 is performed. At this time, when deep chamfering is performed, the outer periphery of the through hole may be circulated several times. After the processing around the through hole 22 on the back surface 21 of the workpiece 19 is completed, the cutting tool 10 is extracted from the through hole 22 of the workpiece 19 as shown in FIG. End or the next processing is performed. The above process becomes the process of the back surface of the workpiece which uses the cutting tool of embodiment.

[Application example]
As an application example of the cutting tool, a cutting tool used for a so-called tap hole in which a thread is formed by threading into a through hole will be described. In addition, about the structure which is common in embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. As shown in FIG. 5, the cutting tool 10A of the application example corresponds to a tapped hole in which a thread 24A is formed around the workpiece 19A as a through hole 22A. The cutting tool 10A of this application example has the same components as the cutting tool 10 of the embodiment, but the size of the cutting surface 18A portion depends on the height of the thread 24A formed in the through hole 22A. Is configured.

  That is, in the cutting part 18A portion of the cutting tool 10A of the application example, the height of the thread 24A formed in the through hole 22A is d, and the difference between the diameter D1 of the blade part 14A and the diameter D2 of the neck part 13A is H ( When D1-D2 = H), the distance half of H (H / 2) is larger than the height d of the screw thread 24A (H / 2> d). At this time, H is a distance perpendicular to the axial direction of the cutting tool 10A of the cutting surface 18A portion of the blade portion 14A, and H / 2 represents one side thereof.

  As described above, when chamfering or deburring the threaded through hole 22A using the cutting tool 10A of the application example, the cutting tool 10A has a blade portion 14A having a size corresponding to the height d of the thread 24A. And the cutting part 18A is formed. As a result, even if the cutting tool is downsized, it is possible to perform chamfering and deburring optimal for the through hole 22A in which the thread 24A is formed. In addition, since the cutting process is common with the said embodiment, description is abbreviate | omitted.

10, 10A: Cutting tool 11: Shank 12: Tapered portion 13, 13A: Neck portion 14, 14A: Blade portion 15: Tip portion 16: Groove 17: Cutting blade 18, 18A: Cutting portion 19, 19A: Workpiece 20: Front surface 21: Back surface 22, 22A: Through hole 23: Waste 24A: Thread

Claims (7)

A blade portion that is inserted from one side of a through-hole formed in the workpiece and is processed while rotating around the through-hole in the other surface of the workpiece, and the blade that is connected to the blade portion A cutting tool having a neck with an outer diameter thinner than the outer diameter of the part,
On the neck side of the blade part, a cutting part for processing the periphery of the through hole in the other surface of the workpiece is formed so as to be inclined at a predetermined angle with respect to the rotation axis .
The cutting part has at least one groove twisted in a direction opposite to the rotating direction, and a cutting edge along the groove on the outer peripheral side of the cutting part. Cutting tools. The diameter of the said blade part becomes like this. Preferably it is formed in 0.5 mm or more and 6.0 mm or less, The cutting tool of Claim 1 characterized by the above-mentioned.   The cutting tool according to claim 1 or 2, wherein a diameter of the blade portion is formed to be twice to three times a diameter of the neck portion. A thread is formed in the through hole,
The cutting tool according to any one of claims 1 to 3, wherein a height of the thread is smaller than a distance that is half of a difference between a diameter of the blade part and a diameter of the neck part.   The cutting tool according to any one of claims 1 to 4, wherein the cutting portion is formed to have an inclination of 30 ° or more and 60 ° or less with respect to the rotation axis. The neck is connected to a shank formed with an outer diameter larger than the outer diameter of the neck,
The connecting portion between the shank and the neck portion has a tapered portion formed by being gradually reduced in diameter from the shank toward the neck portion. The described cutting tool.   A cutting apparatus comprising the cutting tool according to claim 1.