JP2018199179A - Cutting tool, and cutting device including the same - Google Patents

Abstract

To provide a cutting tool which can achieve by one cutting tool, a plurality of functions required for drilling, that is, a drilling function, a hole enlargement function, a chamfering or deburring function of a hole front face side, and a chamfering or deburring function of a hole rear face side, and can make an inner surface shape of a hole smoothly cylindrical.SOLUTION: A cutting tool has a drilling function, a hole enlargement function, a front face deburring or chamfering function, and a rear face deburring or chamfering function, and hole enlargement cutting blades (26,31) dedicated to the hole enlargement function are provided.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cutting tool that can make a hole in a workpiece and can perform chamfering and deburring of a back surface and a front surface smoothly and accurately, 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. Moreover, it may cut so that the hole penetrated may be expanded.

  At this time, when the cutting tool penetrates through the hole on the back surface of the workpiece or when cutting to widen the penetrated hole, a burr may be formed around the hole, so this 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. Moreover, a workpiece such as a cylinder could not be processed because a cutting tool did not enter from the back side. In addition, burrs and corners sometimes appeared around the surface holes when further drilling. Therefore, when drilling a workpiece, a step of penetrating a drill or the like to the back surface of the workpiece, a step of expanding the penetrated hole to a desired size, deburring or chamfering of the front surface There are a process of performing deburring and a process of deburring or chamfering the back surface. For this reason, although a plurality of cutting tools are required, it is desired to reduce the number of times of exchanging the tools as much as possible by using cutting tools that can be used in common in each step.

  The following Patent Document 1 discloses a drill invention having a drilling function, a hole expanding function, a chamfering function on the surface side of the hole, and a chamfering function on the back surface side of the hole with a single drill. According to the invention of this drill, it is possible to make a hole in a workpiece with a rod-shaped drill and a conical drill, and further expand the diameter of the hole with a large-diameter conical drill. A large-diameter conical drill can be used for chamfering the front surface side of the hole, and an inverted conical drill can be used for chamfering the back surface side of the hole. Also, while moving the drill along the inner surface of the widened hole, apply a large-diameter conical drill to the surface side of the hole in the workpiece, and at the same time, apply an inverted conical drill to the back side of the hole in the workpiece. By applying, chamfering on the front side of the hole and chamfering on the back side of the hole can be performed simultaneously.

  The following Patent Document 2 discloses an invention of a double-sided drill having a drilling function, a front surface chamfering function, and a backside chamfering function with a single drill. In the invention of the double-sided drill disclosed in Patent Document 2 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 inclined slightly from the outer diameter blade to the drill body, the outer diameter blade is The first width is extremely narrow and gradually widened from one escape groove to the other escape groove. According to the invention of the double-sided chamfer disclosed in Patent Document 2 below, the drilling operation, the chamfering operation of the workpiece, the chamfering operation of the back surface, and the chamfering operation of the side surface portion are performed together with the front drill blade and the outer diameter blade. Four tasks can be processed simultaneously.

  Patent Document 3 below discloses an invention of a cutting tool having a chamfering or deburring function on the front surface side of a hole and a chamfering or deburring function on the back surface side of the hole with one cutting tool. The cutting tool disclosed in Patent Document 3 below has a first groove twisted in a direction opposite to the rotation direction of the cutting tool on the neck side of the blade part, and a first groove on the outer peripheral side of the blade part along the first groove. A first cutting portion comprising a cutting blade, and a second groove twisted in the direction of rotation of the cutting tool on the tip side of the blade portion, and a second groove on the outer peripheral side of the blade portion along the second groove. It has the 2nd cutting part which consists of two cutting blades. In this cutting tool, the first cutting part is chamfered or deburred by the first cutting part by passing the blade part through the hole and applying the first cutting part to the back side of the hole. At this time, the 1st cutting part has the 1st slot twisted in the direction opposite to the rotation direction of a cutting tool, and the 1st cutting edge on the perimeter side of the blade part along this 1st slot. Therefore, the cut waste is discharged to the back side of the hole. On the other hand, the surface of the hole is chamfered or deburred by applying the second cutting part to the surface side of the hole. At this time, the second cutting part has a second groove twisted in the direction of rotation of the cutting tool and a second cutting edge on the outer peripheral side of the blade part along the second groove. Is discharged to the surface side of the hole. Thereby, when deburring the front surface, the cut debris can be discharged to the front side of the hole, and when deburring the back surface, the cut debris can be discharged to the back side of the hole. Therefore, the cut waste is reliably discharged from the hole of the workpiece, and chamfering and deburring on the front surface side and the back surface side of the hole of the workpiece can be smoothly performed.

Japanese Utility Model Publication No. 51-019268 JP 2000-288813 A JP 2016-112634 A

  In the invention of the drill disclosed in Patent Document 1, drilling, enlargement of the hole, and chamfering of the front surface side and the back surface side of the hole can be performed with one cutting tool. However, in the step of enlarging the hole, cutting is performed while moving the large-diameter conical drill in a direction perpendicular to the workpiece, so that the shape of the hole is limited to a circular shape in plan view. Moreover, since the shape of the large cone drill and the inverted cone drill is a cone shape, the three-dimensional shape of the hole is limited to the cone shape, and the inner diameter shape of the hole cannot be processed into a smooth cylindrical shape. In addition, large-diameter conical drills are commonly used for hole enlargement and chamfering, but in order to enlarge the hole, it is necessary to set the cutting edge to some degree of roughing, while for use in chamfering finishing. Need to set the cutting edge for finishing. For this reason, in order to use in common, it is difficult to set the cutting edge of a large conical drill, and it is extremely difficult to set optimally for both.

  In the invention of the double-sided chamfer drill disclosed in Patent Document 2, drilling and chamfering on the front side and back side of the hole are possible. However, the diameter of the hole depends on the diameter of the drill, and only one diameter hole can be formed with one cutting tool. Further, since the deburring is performed at the drill portion, for example, excessive cutting may occur, which is not suitable for finishing. Further, the chamfering blade for chamfering the back surface side 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. Further, when used for deburring, there is a possibility that a new burr may be generated due to the fact that the burr is pulled to the side, and the deburring process cannot be performed smoothly.

  The cutting tool disclosed in Patent Document 3 can smoothly perform chamfering or deburring on the front surface side and the back surface side of the hole, but this cutting tool does not have a function of drilling or expanding the hole.

  The object of the present invention is to provide a plurality of functions necessary for drilling, that is, a drilling function, a hole expanding function, a chamfering or deburring function on the surface side of the hole, and a chamfering or deburring function on the back surface side of the hole. An object of the present invention is to provide a cutting tool that can be realized by one cutting tool and that can make the inner surface shape of a hole into a smooth cylindrical shape.

  Another object of the present invention is to provide a cutting tool capable of smoothly performing chamfering or deburring.

  Another object of the present invention is to provide a cutting tool capable of simultaneously enlarging a hole and chamfering or deburring.

  Another object of the present invention is to provide a cutting tool capable of smoothly expanding a hole.

  The other object of this invention is to provide the cutting device provided with the said cutting tool.

  The above object of the present invention can be achieved by the following configurations. That is, the cutting tool of the first aspect of the present invention has a drill function, a hole expanding function, a surface deburring or chamfering function, and a back surface deburring or chamfering function, and is dedicated for the hole expanding function. A hole expanding cutting blade is provided.

  A cutting tool according to a second aspect of the present invention is the cutting tool according to the first aspect, wherein a drill cutting edge for the drill function, a surface cutting edge for the surface deburring or chamfering function, and the back surface And a back cutting edge for deburring or chamfering function, and the drill cutting blade, the back cutting blade, the hole expanding cutting blade, and the front cutting blade are each one or plural. It is provided.

The cutting tool of the third aspect of the present invention is the cutting tool of the second aspect, wherein the drill cutting blade is
The hole enlarging cutting blade, the front surface cutting blade, and the back surface cutting blade have functions independent of each other.

  The cutting tool according to a fourth aspect of the present invention is the cutting tool according to the second or third aspect, in order from the tip of the cutting tool, the drill cutting blade, the back cutting blade, the hole expanding cutting blade, and the A cutting edge for the surface is provided.

  The cutting tool according to a fifth aspect of the present invention is the cutting tool according to the fourth aspect, wherein an outer diameter portion is further provided between the drill cutting edge and the back surface cutting edge. .

  The cutting tool according to a sixth aspect of the present invention is the cutting tool according to any one of the second to fifth aspects, wherein the surface cutting blade is provided along a groove twisted in the rotation direction of the cutting tool. It is characterized by that.

  A cutting tool according to a seventh aspect of the present invention is the cutting tool according to any one of the second to sixth aspects, wherein the groove twisted in the rotation direction of the cutting tool includes the surface cutting edge, the hole expanding cutting edge, It is provided continuously and integrally along the drill cutting edge.

  The cutting tool according to an eighth aspect of the present invention is the cutting tool according to any one of the second to seventh aspects, wherein the back surface cutting blade is provided along a groove twisted in a direction opposite to the rotation direction of the cutting tool. It is characterized by being.

  A cutting tool according to a ninth aspect of the present invention is the cutting tool according to any one of the second to eighth aspects, wherein the hole enlarging cutting edge and the surface cutting edge are arranged so as to be simultaneously applied to a workpiece. It is characterized by being.

  A cutting tool according to a tenth aspect of the present invention is the cutting tool according to any one of the second to eighth aspects, wherein the hole enlarging cutting edge and the back surface cutting edge are disposed so as to be simultaneously applied to a workpiece. It is characterized by being.

  A cutting tool according to an eleventh aspect of the present invention is the cutting tool according to any one of the second to tenth aspects, wherein the hole enlarging cutting blade, the front surface cutting blade, and the back surface cutting blade are a workpiece. It arrange | positions so that it may be simultaneously applied to.

  The cutting tool according to a twelfth aspect of the present invention is characterized in that, in the cutting tool according to any one of the first to tenth aspects, the hole-enlarging cutting edge is composed of a roughing cutting edge and a finishing cutting edge.

  The cutting tool according to a thirteenth aspect of the present invention is the cutting tool according to the second aspect, characterized in that the drill cutting edge and the surface cutting edge are common.

  A cutting device according to a fourteenth aspect of the present invention includes the cutting tool according to any one of the first to thirteenth aspects.

  According to the cutting tool of the first aspect of the present invention, a plurality of functions required for drilling, that is, a drilling function, a hole expanding function, a chamfering or deburring function on the surface side of the hole, and a back surface of the hole It is possible to provide a cutting tool capable of realizing the side chamfering or deburring function with one cutting tool and making the inner surface shape of the hole into a smooth cylindrical shape.

  According to the cutting tool of the second aspect of the present invention, there is provided a cutting blade having a drilling function, a hole expanding function, a chamfering or deburring function on the surface side of the hole, and a chamfering or deburring function on the back surface side of the hole. A provided cutting tool can be provided. Further, the number of each cutting edge may be one or plural.

  According to the cutting tool of the third aspect of the present invention, each of the hole drilling function, the hole expanding function, the chamfering or deburring function on the front surface side of the hole, and the chamfering or deburring function on the back surface side of the hole. It is possible to provide a cutting tool having independent cutting blades. Thereby, since the cutting tool is provided with a cutting blade dedicated to each function, an optimum cutting blade can be set for each function.

  According to the cutting tool of the fourth aspect of the present invention, each function can be selected by moving the cutting tool in the vertical direction.

  According to the cutting tool of the fifth aspect of the present invention, the drilling process can be made smoother by further providing the outer diameter portion between the drill cutting edge and the back surface cutting edge.

  According to the cutting tool of the sixth aspect of the present invention, the cutting edge for a surface is provided along a groove twisted in the rotation direction of the cutting tool, so that the cut waste is discharged to the surface side of the hole. Thereby, the deburring or chamfering of the surface of a hole can be performed smoothly.

  According to the cutting tool of the seventh aspect of the present invention, the groove twisted in the rotation direction of the cutting tool is provided continuously and integrally along the surface cutting blade, the hole expanding cutting blade, and the drill cutting blade. Therefore, the cutting of the hole can be performed smoothly by discharging the scraps cut by the cutting edge for the front surface, the cutting blade for expanding the hole and the cutting blade for the back surface of the drill cutting edge to the surface side of the hole.

  According to the cutting tool of the eighth aspect of the present invention, the cutting blade for the back surface is provided along the groove twisted in the direction opposite to the rotation direction of the cutting tool, so that the cut waste is on the back surface side of the hole. By discharging, deburring or chamfering of the back surface of the hole can be performed smoothly.

  According to the cutting tool of the ninth aspect of the present invention, the processing for enlarging the hole and the surface deburring or chamfering can be performed at the same time, so that the number of processing steps can be omitted and the time required for processing is shortened. can do.

  According to the cutting tool of the tenth aspect of the present invention, the processing for enlarging the hole and the back surface deburring or chamfering can be performed at the same time, so that the number of processing steps can be omitted and the time required for processing is shortened. can do.

  According to the cutting tool of the eleventh aspect of the present invention, since the process of enlarging the hole, the front surface deburring or chamfering process, and the back surface deburring or chamfering process can be performed at the same time, the number of processing steps can be omitted. At the same time, the processing time can be shortened.

  According to the cutting tool of the twelfth aspect of the present invention, since the roughing cutting blade and the finishing cutting blade are provided as the hole expanding cutting blade, the processing for expanding the hole with the roughing cutting blade is quickly performed and the finishing cutting is performed. It is possible to finish the surface of the hole smoothly with the blade.

  According to the cutting tool of the thirteenth aspect of the present invention, the cutting blade for the surface can be shared by the drill cutting blade.

  According to the cutting device of the fourteenth aspect of the present invention, it is possible to provide a cutting device that exhibits the effect of the cutting tool.

It is a schematic diagram of a cutting tool. It is a perspective view of a cutting tool. It is a side view of a cutting tool. It is a front view of a cutting tool. It is a schematic diagram which shows the initial state of a drilling process. It is a schematic diagram which shows the state at the time of completion | finish of a drilling process. It is a schematic diagram which shows the roughing process in a hole expansion process. It is a schematic diagram which shows the finishing process in a hole expansion process. It is a schematic diagram which shows a back surface deburring or a chamfering process. It is a schematic diagram which shows surface deburring or chamfering. It is a schematic diagram which shows the case where the roughing process in a hole expansion process and a back surface deburring or a chamfering process are performed simultaneously. It is a schematic diagram which shows the case where the finishing process in a hole expansion process and a surface deburring or a chamfering process are performed simultaneously. It is a schematic diagram which shows the case where a hole expansion process, a back surface deburring or chamfering process, and a surface deburring or chamfering process are performed simultaneously. It is a schematic diagram which shows the case where surface deburring or a chamfering process is performed by a drill part.

  Hereinafter, a cutting tool according to an embodiment of the present invention will be described with reference to the drawings. However, the embodiment shown below exemplifies a cutting tool for embodying the technical idea of the present invention, and does not specify the present invention, and other embodiments included in the scope of the claims. It is equally applicable to the form.

[First Embodiment]
The cutting tool 1 which concerns on 1st Embodiment of this invention is demonstrated with reference to FIGS.

  First, the structure of the cutting tool 1 which concerns on 1st Embodiment of this invention is demonstrated using FIGS. 1-4. 1 is a schematic diagram of the cutting tool, FIG. 2 is a perspective view of the cutting tool, FIG. 3 is a side view of the cutting tool, and FIG. 4 is a front view of the cutting tool.

<Shape of cutting tool 1>
A cutting tool 1 according to an embodiment of the present invention performs drilling, hole enlargement, surface deburring, and backside deburring on a workpiece. The workpiece is processed automatically by attaching a cutting tool 1 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 1 is provided with a drill part 10, an outer diameter part 15, a back surface cutting part 20, a roughing cutting part 25, a finishing cutting part 30, a surface cutting part 35, and a shank 40 in this order from the tip. Are integrally formed. The shank 40 is a portion fixed to the chuck device of the cutting device, and in this embodiment is a cylindrical shape, but may be a prismatic shape such as a hexagonal prism. In the present embodiment, the shank 40 is directly connected to the large-diameter end of the surface cutting portion 35, but the present invention is not limited to this, and when the cutting blade portion of the cutting tool has a small diameter, for example, It is good also as a structure connected to the large diameter shank 40 from the edge part side of the large diameter side of the surface cutting part 35 through the taper part which becomes thick gradually in a taper shape.

  The drill portion 10 has a substantially conical shape such that the tip side is a sharp protrusion, and is used to make a hole having a predetermined diameter in a workpiece. The diameter of the upper part of the drill part 10 (hereinafter, the shank 40 side is referred to as “upward” and the tip side of the drill part 10 is referred to as “downward” for the cutting tool 1) is substantially the same as the diameter of the hole formed in the workpiece. I'm doing it. In the drill portion 10, a plurality of drill grooves 12 are formed by being twisted in the rotation direction of the cutting tool 1. In the present embodiment, the drill groove 12 is described by taking a right-turning cutting device as an example. Therefore, the cutting tool 1 rotates in the right direction, and the drill groove 12 twists in the right direction. When a counterclockwise cutting device is used, the direction in which the drill groove 12 is twisted is the left direction. In the present embodiment, an example in which three drill grooves 12 are provided is shown. However, in the present invention, the number of drill grooves 12 is not limited to three, and even if one, three drill grooves 12 are provided. Other than the above, for example, 2, 4, 5, 6, etc. may be used. A drill cutting edge 11 (see FIGS. 2 to 4) is provided along the drill groove on the side opposite to the rotation direction of each drill groove 12. Therefore, the drill cutting edge 11 is also twisted in the rotational direction of the cutting tool in the same manner as the drill groove 12.

  As shown in FIG. 3, each drill groove 12 is continuously formed with an outer diameter groove 17, a rough cutting groove 27, a finish cutting groove 32, and a surface cutting groove 37. A groove 28 is formed. The same number of cutting grooves 28 as the drill grooves 12 are formed so as to be twisted in the rotational direction of the cutting tool 1. The drill cutting edge 11 and the drill groove 12 are twisted in the rotation direction of the cutting tool, and the cutting groove 28 formed continuously with the drill groove 12 is also twisted in the rotation direction of the cutting tool 1. For this reason, since the shavings of the workpiece by the drill cutting edge 11 are discharged to the surface side of the workpiece (upward in FIG. 1, the direction from the drill portion 10 to the shank 40), the drilling is smoothly performed. It can be performed.

  On the rotation direction side of the drill groove 12, a drill communication groove 13 twisted in the rotation direction of the cutting tool 1 is formed along the drill groove 12. The drill communication groove 13 is connected to the cutting groove 28 on the side opposite to and above the rotation direction of the cutting tool 1 and connected to the communication groove 29 on the upper side. The communication groove 29 is formed in the rotation direction of the cutting tool 1 with respect to the cutting groove 28 and is formed along the cutting groove 28. Similarly to the cutting groove 28, the communication groove 29 is twisted in the rotation direction of the cutting tool 1. Chips of the workpiece by the drill cutting edge 11 are discharged upward through the cutting groove 28 or once through the drill communication groove 13 and then through the cutting groove 28 or the communication groove 29.

When the drill portion 10 is viewed from the side, it becomes a substantially isosceles triangle as shown in FIG. 1, and an angle θ ₁ formed by two sides sandwiching the apex that is the tip of the drill portion 10 in this isosceles triangle is: In the present embodiment, the angle is approximately 90 degrees, but the present invention is not limited to this, and the angle of θ ₁ is appropriately between 30 degrees and 150 degrees, and preferably between 60 degrees and 120 degrees. Can be determined. Further, the angle θ ₂ formed by one of the two sides sandwiching the apex that is the tip of the drill portion 10 in the isosceles triangle is determined according to θ ₁ , and in the present embodiment, θ ₁ is Since it is approximately 90, θ ₂ is approximately 45 degrees.

  In this embodiment, although what formed the drill communication groove | channel 13 was demonstrated, this invention is not limited to this, The thing which used the drill communication groove | channel 13 also as the drill groove | channel 12 in this invention, and drill communication. Those in which all or part of the grooves are omitted are also included.

  Above the drill portion 10, an outer diameter portion 15 that is thin cylindrical or disc-shaped and coincides with the upper diameter of the drill portion 10 is provided. The outer periphery of the outer diameter portion 15 has a smooth arc shape so as to be in sliding contact with the inner periphery of the hole drilled by the drill portion 10, and no cutting edge is provided. The outer diameter portion 15 is provided with the same number of outer diameter grooves 17 as the drill grooves 12 continuously from the respective drill grooves 12. In the present embodiment, the outer diameter portion 15 is not provided with a cutting edge, but if necessary, the outer diameter grooves 17 are provided along the outer diameter grooves 17 on the side opposite to the rotation direction of the cutting tool. An outer diameter cutting blade may be formed as described above. Each outer diameter groove 17 is formed continuously and integrally with the cutting groove 28. The drill communication groove 13 extends to above the outer diameter portion 15 and is connected to the cutting groove 28 and the communication groove 29 above (see FIG. 3).

  Each outer diameter groove 17 is continuously provided from the drill groove 12 and is twisted in the rotational direction. Further, the cutting groove 28 and the connecting groove 29 are also twisted in the rotational direction, so that they are scraped off by the drill cutting edge 11. The shavings of the workpiece are discharged to the surface side of the workpiece, that is, upward. That is, the shavings of the workpiece scraped by the drill cutting edge 11 pass through the cutting groove 28 or once through the drill connecting groove 13 and then through the cutting groove 28 or the connecting groove 29 and upward. Discharged.

  In the present embodiment, the example in which the outer diameter portion 15 is provided has been described. However, the present invention is not limited to this example. For example, the back surface cutting portion 20 is directly provided above the drill portion 10 without providing the outer diameter portion 15. Including those that form Even when the outer diameter portion 15 is not provided, the drill portion 10 can make a hole having a predetermined diameter corresponding to the upper diameter of the drill portion 10.

  Above the outer diameter portion 15, a back surface cutting portion 20 having a substantially inverted truncated cone shape is provided. The back surface cutting portion 20 is used for deburring or chamfering the back surface side of the hole of the workpiece. The lower diameter of the back surface cutting portion 20 is set equal to the diameter of the outer diameter portion 15. A plurality of back surface cutting grooves 22 are formed in the back surface cutting portion. The number of back surface cutting grooves is the same as the number of drill grooves 12, and is three in this embodiment. Each back surface cutting groove 22 is twisted in the direction opposite to the rotation direction of the cutting tool 1 (see FIGS. 2 and 3). On the side opposite to the rotation direction of the cutting tool 1 of each back surface cutting groove 22, a back surface cutting edge 21 (see FIG. 3) is formed along each back surface cutting groove 22. When the back surface cutting part 20 is applied to the back surface of the hole of the workpiece to perform deburring or chamfering of the back surface of the hole of the workpiece, the back surface cutting groove 22 and the back surface cutting blade 21 are set in the rotational direction of the cutting tool 1. Are twisted in the opposite direction, so that the shavings of the workpiece scraped by the back-side cutting blade 21 are discharged to the back side of the workpiece, that is, downward. Thereby, the deburring or chamfering of the back surface side of the hole of a workpiece can be performed smoothly.

  In the present embodiment, the example in which the outer diameter portion 15 is provided has been described. However, when the outer diameter portion 15 is not provided, the back surface cutting portion 20 is formed directly above the drill portion 10. In this case, the upper diameter of the drill portion 10 and the lower diameter of the back surface cutting portion 20 coincide with each other.

When the back surface cutting portion 20 is viewed from the side, it becomes a substantially isosceles trapezoid as shown in FIG. 1, and the angle formed by one of the opposing inclined sides of the isosceles trapezoid and the axis of the cutting tool 1. θ ₃ is approximately 45 degrees in the present embodiment, but is not limited to this in the present invention. For example, θ ₃ is appropriately determined between 30 degrees and 60 degrees.

  A substantially cylindrical roughing cutting portion 25 is provided above the back surface cutting portion 20. The roughing cutting part 25 is used for processing for enlarging a hole made by the drill part 10. The roughing cutting part 25 is substantially cylindrical, and the diameter of the roughing cutting part 25 coincides with the upper diameter of the back surface cutting part 20. A plurality of rough cutting grooves 27 are formed in the rough cutting part 25. The number of roughing cut grooves 27 matches the number of drill grooves. Each rough cutting groove 27 is formed integrally with the cutting groove 28. That is, each rough cutting groove 27 is formed integrally with the drill groove 12 via the outer diameter groove 17 in the lower part, and each rough cutting groove 27 is continuous with the finish cutting groove 32 and the surface cutting groove 37 in the upper part. In addition, the cutting tool 1 is twisted in the rotation direction. Further, a communication groove 29 (see FIG. 3) that is twisted in the rotation direction of the cutting tool 1 is formed along the rough cutting groove 27 on the rotation direction side of the cutting tool 1 in each rough cutting groove 27. Has been.

  A rough cutting edge 26 (see FIGS. 2 and 3) is formed along the rough cutting groove 27 in the direction opposite to the rotation direction of the cutting tool 1 of each rough cutting groove 27. Since the roughing cutting groove 27 and the roughing cutting edge 26 are twisted in the rotation direction of the cutting tool 1, the shavings of the workpiece scraped by the roughing cutting edge 26 are on the surface side of the workpiece, that is, By discharging upward, roughing processing for enlarging the hole can be performed smoothly. The shavings of the workpiece cut off by the roughing cutting edge 26 are discharged upward through the cutting groove 28 or through the communication groove 29 formed along the cutting groove 28. Moreover, since the roughing cutting edge 26 is set to be rough, the process of enlarging the hole can be performed quickly.

  A finish cutting part 30 is provided above the roughing cutting part 25. The finish cutting part 30 is used for processing to smoothly finish the inner surface of the hole after the hole made by the drill part 10 is enlarged by the roughing cutting part 25. The finish cutting part 30 has a substantially cylindrical shape, and the diameter of the finish cutting part 30 is substantially the same as the diameter of the roughing cutting part 25. The finish cutting portion 30 is provided with a plurality of finish cutting grooves. Each finish cutting groove is twisted in the rotation direction of the cutting tool 1 and is formed continuously and integrally with the cutting groove 28. That is, a rough cutting groove 27 is continuously formed below each finish cutting groove 32, and a surface cutting groove 37 is continuously formed above, and a continuous cutting groove 28 is formed as a whole. Yes. The number of finish cutting grooves 32 is the same as the number of rough cutting grooves 27 and surface cutting grooves 37, and is three in this embodiment. Communication grooves 29 (see FIG. 3) are provided along the finishing cutting grooves 32 on the rotational direction side of the cutting tool 1 with respect to the respective finishing cutting grooves 32. The cutting grooves 28 and the communication grooves 29 are provided as follows. The cutting tool 1 is twisted in the rotational direction.

  A finishing cutting edge 31 (see FIGS. 2 and 3) is formed along the finishing cutting groove 32 in the opposite direction of the cutting tool 1 with respect to the finishing cutting groove 32. Since the finish cutting groove 32 and the finish cutting edge 31 are formed by twisting in the rotation direction of the cutting tool 1, the shavings of the workpiece scraped by the finishing cutting edge 31 are the surface side of the workpiece, that is, the workpiece side. By discharging upward, the finishing process of smoothing the inner surface of the hole can be performed smoothly. The shavings of the workpiece cut off by the finishing cutting edge 31 are discharged upward through the cutting groove 28 or through the communication groove 29 formed along the cutting groove 28. The finishing cutting edge 31 is set to be a fine cutting edge so that the inner surface of the hole can be smoothly finished.

  A surface cutting portion 35 is provided above the finishing cutting edge 31. The surface cutting part 35 is used for deburring or chamfering the surface side of the hole of the workpiece. The surface cutting part 35 is formed in a substantially truncated cone shape. The lower diameter of the surface cutting portion 35 is substantially the same as the diameter of the substantially cylindrical finishing cutting portion 30. The surface cutting part 35 is provided with a plurality of surface cutting grooves 37. Each surface cutting groove is twisted in the rotation direction of the cutting tool 1, is continuous with the finish cutting groove 32 below, and is continuously formed integrally as the cutting groove 28. A communication groove 29 (see FIG. 3) is formed along the surface cutting groove 37 on the rotational direction side of the cutting tool 1 with respect to the surface cutting groove 37, and the cutting groove 28 and the communication groove 29 are formed by the cutting tool. 1 is formed so as to be twisted in the direction of rotation.

  On the opposite side of the rotation direction of the cutting tool 1 with respect to the surface cutting groove 37, a surface cutting edge 36 is provided along the surface cutting groove 37. Since the surface cutting groove 37 and the surface cutting edge 36 are twisted in the rotation direction of the cutting tool 1, the shavings of the workpiece scraped by the surface cutting edge 36 are on the surface side of the workpiece, that is, upward. As a result, the deburring or chamfering on the surface side of the hole of the workpiece can be smoothly performed. The shavings of the workpiece cut by the surface cutting blade 36 are discharged upward through the cutting groove 28 or through the communication groove 29 formed along the cutting groove 28.

When the surface cutting portion 35 is viewed from the side, it becomes a substantially isosceles trapezoid as shown in FIG. 1, and the angle formed by one of the opposing inclined sides of the isosceles trapezoid and the axis of the cutting tool 1. θ ₄ is approximately 45 degrees in the present embodiment, but is not limited to this in the present invention. For example, θ ₃ is appropriately determined between 30 degrees and 60 degrees.

  A shank 40 is provided above the surface cutting portion 35. In the present embodiment, the upper diameter of the surface cutting portion 35 coincides with the diameter of the shank 40. However, it is good also as a structure connected to the large diameter shank 40 from the upper direction of the surface cutting part 35 through the taper part which becomes thick gradually in a taper shape.

  In the present embodiment, the communication groove 29 formed along the cutting groove 28 has been described. However, the present invention is not limited to this, and the communication groove 29 is also used as the cutting groove 28 in the present invention. The thing which abbreviate | omitted all or one part of the communication groove | channel 29 is also included. In the present embodiment, the example in which the finish cutting part 30 is formed above the rough cutting part 25 has been described. However, the present invention is not limited to this, and the present invention is above the finish cutting part 30. The thing provided with the roughing cutting part 25 is included.

<Processing procedure>
With reference to FIGS. 5-10, the process which drills a workpiece | work using the cutting tool 1, expands a hole, and performs the deburring or chamfering of the surface side and back surface side of a hole is demonstrated.

(1) First, a process of making a hole in the workpiece 45 will be described. As shown in FIG. 5, when the tip of the drill unit 10 is applied to the surface 46 of the workpiece 45 and the cutting tool 1 is pushed down, a hole is made in the workpiece 45 by the drill cutting edge 11. Can continue. When the cutting tool 1 is further pushed downward from the surface 46 of the workpiece 45, a cylindrical hole having a diameter corresponding to the upper diameter of the drill portion 10 is formed in the workpiece 45, and the hole The outer periphery of the outer diameter portion 15 is in sliding contact with the inner periphery. In FIG. 6, the drill part 10 has shown the place which penetrated the to-be-processed object 45 completely. Even when the outer diameter portion 15 is not provided, a cylindrical hole corresponding to the diameter above the drill portion 10 is opened by the drill cutting edge 11 of the drill portion 10.

  When the workpiece 45 is shaved because the cutting groove 28 continuously provided from the drill groove 12, the drill connecting groove 13, and the connecting groove 29 are formed by being twisted in the rotation direction of the cutting tool 1. The generated shavings are discharged to the surface side of the hole, that is, upward. For this reason, the process which makes the hole 48 in the to-be-processed object 45 with the drill cutting blade 11 can be performed smoothly.

(2) Next, the process of enlarging the hole 48 with the roughing cutting edge 26 (see FIGS. 1 to 3) of the roughing cutting portion 25 will be described. As shown in FIG. 7, the roughing cutting portion 25 is formed so as to draw a circle in plan view along the inner periphery of the cylindrical hole 48 of the workpiece 45 opened in (1) above. The hole 48 is enlarged by being pressed against the inner periphery of the 45 cylindrical holes 48. Since the roughing cutting edge 26 is set to be rough, processing for expanding the hole can be performed quickly.

  The roughing cutting groove 27 and the cutting groove 28 provided continuously and the communication groove 29 are formed by twisting in the rotation direction of the cutting tool 1, so that the workpiece 45 is cut by the roughing cutting edge 26. The shavings generated at the time of discharge are discharged to the surface side of the hole, that is, upward. For this reason, the process which expands the hole 48 of the to-be-processed object 45 with the roughing cutting blade 26 can be performed smoothly.

(3) Next, a process of smoothly finishing the enlarged hole 48 with the finishing cutting edge 31 (see FIGS. 1 to 3) of the finishing cutting part 30 will be described. As shown in FIG. 8, the finishing cutting edge 31 of the finishing cutting section 30 is drawn so as to draw a circumference in plan view along the inner periphery of the cylindrical hole 48 of the workpiece 45 enlarged in the above (2). Is pressed against the inner periphery of the cylindrical hole 48 of the workpiece 45, so that the inner periphery of the hole 48 is smoothly finished. Since the finishing cutting edge 31 is set to be a fine cutting edge, the inner surface of the hole can be smoothly finished.

  When the workpiece 45 is cut by the finishing cutting edge 31 because the cutting groove 28 provided continuously with the finishing cutting groove 32 and the connecting groove 29 are formed by being twisted in the rotation direction of the cutting tool 1. The shavings generated in the above are discharged to the surface side of the hole, that is, upward. For this reason, the finishing cutting edge 31 can smoothly perform the process of smoothly finishing the inner peripheral surface of the hole 48 of the workpiece 45.

(4) Next, the process of deburring or chamfering the back surface of the hole 48 will be described. As shown in FIG. 9, the back surface cutting portion 20 is formed so as to draw a circle in a plan view along the inner surface on the back surface side of the cylindrical hole 48 whose inner surface is smoothly processed in the above (3). Deburring of the inner periphery on the rear surface side of the hole 48 by pressing the rear cutting edge 21 (see FIGS. 1 and 3) from the inner peripheral side on the rear surface side and the lower side of the cylindrical hole 48 of the workpiece 45. Can be chamfered. The inclination angle θ ₃ of the back surface cutting portion 20 is appropriately set, for example, 45 degrees, and the back surface cutting blade 21 is set to a fineness suitable for deburring or chamfering, so that the back surface side of the hole Can be appropriately deburred or chamfered.

  Since the back surface cutting groove 22 twisted in the direction opposite to the rotation direction of the cutting tool 1 is formed in the back surface cutting portion 20, shavings generated when the workpiece 45 is cut by the back surface cutting blade 21. Is discharged to the back side of the hole, that is, downward. For this reason, the deburring or chamfering process on the back surface 47 side of the workpiece 45 can be smoothly performed by the back surface cutting blade 21.

(5) Next, the process of deburring or chamfering the surface 46 of the hole 48 will be described. As shown in FIG. 10, the surface cutting portion 35 is formed so as to draw a circle in a plan view along the inner periphery on the surface side of the cylindrical hole 48 whose inner peripheral surface is processed smoothly in the above (3). Deburring the inner periphery on the surface side of the hole 48 by pressing the surface cutting edge 36 (see FIGS. 1 to 3) from the inner periphery side on the surface side of the cylindrical hole 48 of the workpiece 45 or from above. Can be chamfered. The inclination angle θ ₄ of the surface cutting portion 35 is appropriately set to 45 degrees, for example, and the surface cutting edge 36 is set to a fineness suitable for deburring or chamfering. Can be appropriately deburred or chamfered.

  A surface cutting groove 37 that is twisted in the rotation direction of the cutting tool 1 is formed in the surface cutting portion 35 continuously with the cutting groove 28, and a connecting groove 29 is also twisted in the rotation direction of the cutting tool 1. Therefore, the shavings generated when the workpiece 45 is cut by the surface cutting edge 36 are discharged to the surface side of the hole, that is, upward. For this reason, it is possible to smoothly perform deburring or chamfering on the surface 46 side of the workpiece 45 by the surface cutting edge 36.

  In the present embodiment, the example in which the step of deburring or chamfering the surface 46 of the hole 48 in the above (5) has been described after the step of deburring or chamfering the back surface of the hole 48 in the above (4). The present invention is not limited to this, and the step (4) may be performed after the step (5).

[Second Embodiment]
A processing procedure by the cutting tool 1 according to the second embodiment of the present invention will be described with reference to FIGS. 11 and 12. FIG. 11 is a schematic diagram showing a case where the roughing process in the hole expansion process and the back surface deburring or chamfering process are performed simultaneously. The same reference numerals are used for configurations common to FIGS. 1 to 10, and descriptions thereof are omitted.

  In the processing procedure according to the second embodiment, the step (2) of enlarging the hole 48 with the roughing cutting blade 26 and the step (4) of deburring or chamfering the back surface of the hole 48. It differs from the processing procedure according to the first embodiment in that it is performed simultaneously.

  As shown in FIG. 11, in the step of enlarging the hole 48 of the above (2) with the roughing cutting blade 26, the circumference is seen in plan view along the inner periphery of the cylindrical hole 48 of the workpiece 45. As illustrated, the rough cutting part 25 is pressed against the inner periphery of the cylindrical hole 48 of the workpiece 45, and at the same time, the back surface cutting of the back surface cutting part 20 is placed on the back surface 47 side of the hole 48 of the workpiece 45. The step of expanding the hole 48 of the above (2) by the rough cutting blade 26 by arranging the cutting tool 1 at the position where the blade 21 (see FIGS. 1 and 3) hits, and the hole of the above (4) The process of deburring or chamfering the back surface of 48 can be performed simultaneously.

  The roughing cutting groove 27 and the cutting groove 28 provided continuously and the communication groove 29 are formed by twisting in the rotation direction of the cutting tool 1, so that the workpiece 45 is cut by the roughing cutting edge 26. The shavings generated at the time of discharge are discharged to the surface side of the hole, that is, upward. On the other hand, since the back surface cutting groove 22 twisted in the direction opposite to the rotation direction of the cutting tool 1 is formed in the back surface cutting portion 20, it occurs when the workpiece 45 is cut by the back surface cutting blade 21. The shavings are discharged to the back side of the hole, that is, downward. As a result, both the step (2) of enlarging the hole 48 by the roughing cutting blade 26 and the step (4) of deburring or chamfering the back surface of the hole 48 can be performed simultaneously. Processing can be performed smoothly.

  In the second embodiment, after the step (2) of enlarging the hole 48 by the roughing cutting blade 26 and the step (4) of deburring or chamfering the back surface of the hole 48 are performed at the same time. The enlarged hole 48 is smoothly finished by the finishing cutting edge 31. However, when burrs are generated in the process of finishing the hole 48 smoothly by the finishing cutting edge 31, the back side of the hole 48 is again used for the back side. Deburring or chamfering can be performed by applying the cutting edge 21. When the rough cutting part 25 is provided above the finish cutting part 30, the process of smoothly finishing the enlarged hole 48 with the finishing cutting edge 31, and the back surface of the hole 48 is deburred or The chamfering process can be performed simultaneously.

[Third Embodiment]
A processing procedure by the cutting tool 1 according to the third embodiment of the present invention will be described with reference to FIG. FIG. 12 is a schematic diagram showing a case where the finishing process in the hole enlargement process and the surface deburring or chamfering process are simultaneously performed. The same reference numerals are used for configurations common to FIGS. 1 to 11 and description thereof is omitted.

  In the processing procedure according to the third embodiment, the step of smoothly finishing the enlarged hole 48 of the above (3) with the finishing cutting edge 31 (FIGS. 1 to 3) of the finishing cutting part 30 and the above (5) This is different from the processing procedure according to the first embodiment in that the process of deburring or chamfering the surface 46 of the hole 48 is simultaneously performed.

  As shown in FIG. 12, in the step of smoothly finishing the enlarged hole 48 of the above (3) with the finishing cutting edge 31, a circle in plan view is formed along the inner periphery of the cylindrical hole 48 of the workpiece 45. At the same time that the finishing cutting edge 31 is pressed against the inner periphery of the cylindrical hole 48 of the workpiece 45 so as to draw a circumference, the surface cutting portion 35 is applied to the surface 46 side of the hole 48 of the workpiece 45. By placing the cutting tool 1 at a position where the cutting edge 36 (see FIGS. 1 to 3) hits, the step of smoothly finishing the enlarged hole 48 of the above (3) with the finishing cutting edge 31, and the above (5) The step of deburring or chamfering the surface 46 of the hole 48 in FIG.

  The cutting groove 28 provided continuously with the finishing cutting groove 32 and the surface cutting groove 37 and the connecting groove 29 are formed by being twisted in the rotation direction of the cutting tool 1, so that the workpiece is processed by the finishing cutting edge 31. The shavings generated when the 45 is shaved and the shavings generated when the workpiece 45 is shaved by the surface cutting blade 36 are discharged to the surface side of the hole 48, that is, upward. As a result, the step (3) of finishing the enlarged hole 48 smoothly with the finishing cutting edge 31 and the step (5) of deburring or chamfering the surface 46 of the hole 48 are also performed simultaneously. Both processes can be performed smoothly.

  In the case where the roughing cutting part 25 is provided above the finish cutting part 30, a process of expanding the hole 48 with the roughing cutting blade 26 and a process of deburring or chamfering the surface of the hole 48. Can be done simultaneously. In this case, after simultaneously performing the step of enlarging the hole 48 with the roughing cutting edge 26 and the step of deburring or chamfering the surface of the hole 48, the enlarged hole 48 is smoothly finished with the finishing cutting edge 31. However, when burrs are generated in the step of smoothly finishing the hole 48 with the finishing cutting edge 31, deburring or chamfering is performed by applying the surface cutting edge 36 to the surface side of the hole 48 again. be able to.

[Fourth Embodiment]
A processing procedure by the cutting tool 1A according to the fourth embodiment of the present invention will be described with reference to FIG. FIG. 13 is a schematic diagram showing a case where hole enlargement processing, backside deburring or chamfering, and front surface deburring or chamfering are performed simultaneously. The same reference numerals are used for configurations common to FIGS. 1 to 12 and descriptions thereof are omitted.

  The processing procedure according to the fourth embodiment relates to the first embodiment in that the step of enlarging the hole 58, the backside deburring or chamfering process, and the front surface deburring or chamfering process are performed simultaneously. It is different from the processing procedure. In 4th Embodiment, there is no distinction with the rough cutting part 25 and the finish cutting part 30, and the hole expansion cutting part 50 in which the hole expansion cutting blade which is not shown in figure is formed is provided.

  The length dimension of the hole expanding cutting portion 50 (the length dimension in the axial direction of the cutting tool 1) is set to substantially match the thickness of the workpiece 55. For this reason, when the hole enlargement cutting part 50 is applied to the inner peripheral surface of the hole 58 of the workpiece 55 on the workpiece, at the same time, the rear cutting edge 21 ( 1 (see FIGS. 1 and 3), and the surface cutting edge 36 (see FIGS. 1 to 3) of the surface cutting portion 35 comes into contact with the surface 56 side of the hole of the workpiece 55. Therefore, in the fourth embodiment, enlargement of the hole 58 by the hole enlargement cutting unit 50, deburring or chamfering of the hole 58 on the back surface 57 side by the back surface cutting blade 21, and the surface 56 of the hole 58 by the front surface cutting blade 36. Side deburring or chamfering can be performed simultaneously. The hole enlargement cutting part 50 is provided with a hole enlargement cutting groove and a hole enlargement cutting blade (not shown). The hole expansion cutting groove is provided continuously and integrally with the drill groove and the surface cutting groove 37, and is twisted in the rotation direction of the cutting tool 1A.

  The length dimension of the hole expansion cutting portion 50 is set to be equal to the thickness of the workpiece 55 or slightly shorter than the thickness of the workpiece 55. When the length dimension of the hole enlargement cutting part 50 is equal to the thickness of the workpiece 55, the deburring of the back surface 57 side of the hole 58 by the back surface cutting blade 21 and the surface of the hole 58 by the front surface cutting blade 36 are performed. The deburring on the 56 side can be performed simultaneously with the enlargement of the hole 58 by the hole enlargement cutting unit 50. When the length dimension of the hole enlargement cutting part 50 is set to a dimension slightly shorter than the thickness of the workpiece 55, the chamfer corresponding to the dimension slightly shorter than the thickness of the workpiece 55 is provided. That is, the chamfering on the back surface 57 side of the hole 58 by the back surface cutting blade 21 and the chamfering on the front surface 56 side of the hole 58 by the front surface cutting blade 36 are performed simultaneously with the expansion of the hole 58 by the hole expanding cutting portion 50. be able to.

[Fifth Embodiment]
A processing procedure by the cutting tool 1B according to the fifth embodiment of the present invention will be described with reference to FIG. FIG. 14 is a schematic diagram showing a case where surface deburring or chamfering is performed by a drill portion. The same reference numerals are used for configurations common to FIGS. 1 to 13 and description thereof is omitted.

  The processing procedure according to the fifth embodiment differs from the processing procedure according to the first embodiment in that the drill unit 10 is used to deburr or chamfer the surface 46 side of the hole 48 of the workpiece 45. When deburring or chamfering the surface 46 side of the hole 48 of the workpiece 45, a drill is performed from above the hole 48 of the workpiece and from the inner peripheral surface side of the hole 48 with the cutting tool 1 </ b> B rotated. The cutting tool 1B is moved so that the drill cutting edge 11 of the part 10 is pressed and the drill part 10 follows the inner periphery of a hole.

  In the fifth embodiment, since the deburring or chamfering is performed on the surface 46 side of the hole 48 of the workpiece 45 using the drill unit 10, the drill unit 10 is used for both the drill function and the surface deburring or chamfering function. Therefore, it is not necessary to provide a separate surface cutting portion 35, and the structure of the cutting tool 1 can be simplified. Further, the cutting groove 28, the drill connecting groove 13 and the connecting groove 29 formed continuously with the drill groove 12 are twisted in the rotation direction of the cutting tool 1B, and therefore are cut by the drill cutting edge 11 of the drill portion 10. The shavings of the workpiece 45 are discharged to the surface side of the workpiece, that is, the upper side. For this reason, the deburring or chamfering of the surface 46 of the workpiece 45 by the drill cutting edge 11 can be performed smoothly.

DESCRIPTION OF SYMBOLS 1, 1A, 1B ... Cutting tool 10 ... Drill part 11 ... Drill cutting edge 12 ... Drill groove 13 ... Drill communication groove 15 ... Outer diameter part
17 ... Outer diameter groove 20 ... Back surface cutting portion 21 ... Back surface cutting blade 22 ... Back surface cutting groove 25 ... Roughing cutting portion 26 ... Roughing cutting blade 27 ... Roughing cutting groove 28 ... Cutting groove 29 ... Communication groove 30 ... Finish Cutting part 31 ... Finishing cutting edge 32 ... Finishing cutting groove 35 ... Surface cutting part 36 ... Surface cutting edge 37 ... Surface cutting groove 40 ... Shank 45 ... Workpiece 46 ... Surface 47 ... Back face 48 ... Hole 50 ... Hole expansion cutting Part
55 ... Workpiece 56 ... Front 57 ... Back 58 ... Hole

Claims (14)

Drill function and
With hole expansion function,
Surface deburring or chamfering function,
A backside deburring or chamfering function,
A cutting tool characterized in that a dedicated hole expanding cutting blade for a hole expanding function is provided. A drill cutting edge for the drill function;
A surface cutting edge for the surface deburring or chamfering function;
A back cutting edge for the back deburring or chamfering function;
Is further provided,
2. The cutting tool according to claim 1, wherein one or a plurality of the drill cutting blade, the back surface cutting blade, the hole expanding cutting blade, and the front surface cutting blade are provided. The drill cutting edge;
The hole enlarging cutting blade;
The surface cutting blade;
The back surface cutting blade;
The cutting tools according to claim 2, which have functions independent of each other. In order from the tip of the cutting tool,
The drill cutting edge,
The cutting blade for the back surface,
The cutting tool according to claim 2 or 3, wherein the hole enlarging cutting edge and the surface cutting edge are provided.   The cutting tool according to claim 4, further comprising an outer diameter portion between the drill cutting edge and the back surface cutting edge.   The cutting tool according to any one of claims 2 to 5, wherein the surface cutting edge is provided along a groove twisted in a rotation direction of the cutting tool.   The groove twisted in the rotating direction of the cutting tool is provided continuously and integrally along the surface cutting blade, the hole expanding cutting blade, and the drill cutting blade. The cutting tool according to any one of 6.   The cutting tool according to any one of claims 2 to 7, wherein the back surface cutting edge is provided along a groove twisted in a direction opposite to a rotation direction of the cutting tool.   The cutting tool according to any one of claims 2 to 8, wherein the hole enlarging cutting edge and the surface cutting edge are disposed so as to be simultaneously applied to a workpiece.   The cutting tool according to any one of claims 2 to 8, wherein the hole enlarging cutting edge and the back surface cutting edge are disposed so as to be simultaneously applied to a workpiece.   The said hole expansion cutting blade, the said surface cutting blade, and the said back surface cutting blade are arrange | positioned so that it may be simultaneously applied to a workpiece, The Claim 1 characterized by the above-mentioned. The described cutting tool.   The cutting tool according to any one of claims 1 to 10, wherein the hole enlargement cutting edge includes a roughing cutting edge and a finishing cutting edge.   The cutting tool according to claim 2, wherein the drill cutting edge and the surface cutting edge are common.   A cutting apparatus comprising the cutting tool according to claim 1.