JP4468012B2 - Rotating drill - Google Patents

Description

  The present invention relates to a rotary drilling tool for drilling a synthetic resin material or a rubber material attached to a tool such as an electric drill or an air drill, and more specifically, a drilling process for a molded product made of synthetic resin for a sash or the like. The present invention relates to a rotary punch suitable for the above.

Conventionally, when a hole is made in a soft material such as synthetic resin or rubber with a drill for metal processing or woodworking, the hole shape does not become a perfect circle, and many burrs are generated, which requires manual finishing. There was a problem.
Also, with commercially available hole saws, burrs and core residue occur, making it difficult to drill holes with good dimensional accuracy, and the end mill can only be used with a dedicated machine tool, and is limited in use and lacks versatility. There was a problem.
In order to solve these problems, (Patent Document 1) states that “the main body part connected to the shank is a cylinder concentric with the rotating shaft, the tip edge of this cylinder is a cutting edge, and further, the inner surface of the cylinder is A rotary drilling tool "is disclosed that includes a cutting edge in the radial direction protruding from at least to the center of the cylinder.
In addition, (Patent Document 2) states that “a main body provided with a connecting portion that can be detachably connected to a rotary tool is provided with a cylindrical portion having an opening on the distal end side, and a distal end opening edge of the cylindrical portion is provided. There is disclosed a drilling tool provided with cutting teeth, and provided with a shavings discharge port for discharging shavings communicating with a cylindrical hole of the cylindrical portion on the peripheral surface of the cylindrical portion.
In addition, (Patent Document 3) states that, “Using a drill bit having a blade at the tip and having a hole penetrating in the axial direction, a gas is blown out from the penetrating hole to the blade, A prepreg drilling method in which a plurality of prepregs in which a base material is impregnated with a resin composition is drilled in a stacked prepreg stack is disclosed.
Japanese Patent Laid-Open No. 7-9396 JP-A-11-899 JP 2000-15632 A

However, the above conventional techniques have the following problems.
(1) In the rotary drilling tool of (Patent Document 1), since the tip end of the cylinder is a cutting edge, it is difficult to confirm the drilling position, and the drilling position accuracy cannot be ensured. The problem was lacking in reliability and reliability.
In addition, because the cutting edge at the tip edge is formed along the inner periphery of the cylinder, the edge of the hole cannot be chamfered, and finishing must be performed using another tool. It had the problem of lacking in nature.
(2) Since the drilling tool of (Patent Document 2) has cutting teeth at the tip opening edge of the cylindrical portion, it is difficult to confirm the drilling position as in (Patent Document 1), and the position of drilling There was a problem that accuracy could not be secured and workability and reliability were lacking.
Also, since the cutting teeth are only at the opening edge at the tip of the cylindrical part, the hole cannot be hollowed out when the workpiece is thick or the rib is formed at the bottom of the processed part. Occurred and lacked workability and workability.
(3) In the drilling method of (Patent Document 3), since a drill bit having a blade only at the tip is used, a hole is formed when the workpiece is thick or a rib is formed in the lower part of the workpiece. In other words, there is a problem that the core remains and the workability and workability are poor.
In addition, drilling is performed while blowing gas from the axially penetrating hole to the blade part, so that machining can be performed while cooling the blade, etc., but the structure becomes complicated and a dedicated tool must be used. Therefore, there was a problem of lack of workability and versatility.

  The present invention solves the above-described conventional problems, and can be easily attached to an existing tool for use and has excellent versatility, with a simple configuration and no burrs or core residue, and accurate positioning accuracy. Drilling can be performed with roundness, excellent in reliability and workability, and after drilling, the edge of the processed hole can be chamfered at the same time. An object of the present invention is to provide a rotary drilling tool that is excellent in dischargeability, can be used continuously, and is excellent in reliability and maintenance.

In order to solve the above-described problems, the rotary drilling tool of the present invention has the following configuration.
According to a first aspect of the present invention, there is provided a rotary drilling tool comprising a shank connected to a tool body such as an electric drill or an air drill, and a through-hole drilled in parallel with a longitudinal direction of an axis. A cylindrical main body sleeve provided continuously, a chip discharge port that opens to the side surface of the main body sleeve in communication with the through hole of the main body sleeve, and an outer end of the main body sleeve that is disposed at the tip of the main body sleeve. A drill head having a cylindrical portion formed with a diameter smaller than the diameter, and the drill head is connected to a tip drill portion and a base portion of the tip drill portion from the axis of the tip drill portion. An inner hollow blade formed toward the inner peripheral surface of the drill head, a tip cutting blade formed in a step shape in the axial direction on the tip circumference of the drill head, and the cylindrical portion of the drill head. The main body from the outer periphery of the lower end It has the structure includes a chamfered hole drilled to communicate with the through hole of the sleeve, a.
This configuration has the following effects.
(1) Since the drill head has the tip drill portion, alignment can be easily performed, and the tip drill portion can be used as a guide to perform drilling at an accurate position by the inner hollow blade and the tip cutting blade.
(2) The tip cutting edge is formed in a stepped shape in the axial direction on the tip circumference of the drill head, and the inner cut-out blade is connected to the base of the tip drill part, from the axis of the drill head toward the inner peripheral surface. By being formed, the outer periphery of the hole can be cut with the cutting edge of the tip, and the inside of the hole can be cut with the inner cut-off blade, so that no core residue or burrs are generated, and the roundness is high. Drilling can be performed.
(3) Since the inner drilling blade is formed continuously from the axial center of the tip drill portion toward the inner peripheral surface of the drill head, the tip drill portion is supported by the inner drilling blade. Therefore, it is possible to perform highly accurate drilling using the tip drill portion as a guide.
(4) Since the drill head disposed at the tip of the main body sleeve has a chip discharge port that communicates with the through hole of the main body sleeve and opens on the side surface of the main body sleeve and is formed in a cylindrical shape, the main body sleeve Chips generated by the drill head at the tip of the drill can be sent to the through hole of the rear body sleeve and discharged from the chip discharge port, preventing chip clogging at the drill head, Excellent discharge.
(5) Since there is a chamfering hole drilled from the outer periphery of the lower end of the cylindrical portion of the drill head to the through hole of the main body sleeve, the periphery of the hole machined by the chamfering hole is chamfered at the end of the drilling process. Therefore, it is not necessary to perform finishing using another tool or the like, and workability can be improved.
(6) Since the chamfering hole is formed in communication with the through hole of the main body sleeve, the chamfered chips can be sent to the through hole and discharged from the chip discharge port. Occurrence can be prevented.

Here, the shank is formed in a substantially cylindrical shape, a substantially frustoconical shape, or the like. Thereby, it can be easily connected to a tool body such as an existing electric drill or air drill. The end of the shank is fitted into the through hole of the main body sleeve and fixed by screwing or the like. A pipe made of stainless steel or the like is suitably used for the main body sleeve. In particular, when the inner peripheral surface of the through hole is polished smoothly, the chip discharge property can be improved, and the reliability is excellent.
The chip discharge port is formed in a substantially circular shape, a substantially elliptical shape having a long axis parallel to the longitudinal direction of the main body sleeve, a long hole shape, or the like. In particular, it is excellent in chip discharge property by forming it into a substantially elliptical shape or a long hole shape to widen the opening area. In addition, when combined with a chip suction device, chips can be collected and discarded without taking out the chip almost to the outside, and workability is excellent.
As the material of the drill head, SK material that is carbon tool steel, SKS material of alloy tool steel, high-grade high alloy HSS, cemented carbide and the like are preferably used. By quenching the drill head, the wear resistance can be improved, and the stability and long life are excellent.
The tip drill portion of the drill head is formed so that the tip projects at the center of the drill head. As a result, since the tip drill portion can be first applied to the workpiece during drilling, the positioning can be easily performed and the tip drill portion can be reliably used as a guide. Moreover, it is preferable that the tip outer periphery of the drill head is polished. Thereby, generation | occurrence | production of a burr | flash can be prevented and accurate drilling can be performed.

The number of inner cut-out blades is preferably 2-4. If there is one inner cutting blade, the tip drill will be cantilevered, and the tip drill will not be able to be reliably supported, and will be more likely to be eccentric. The opening area is reduced, chip dischargeability is reduced, and clogging tends to occur, which is not preferable.
The inner hollow blade may be a straight blade or a twisted blade. When the inner cut-out blade is a twisted blade, cutting performance can be improved compared to a straight blade, and the workability is excellent.
The tip cutting edge is formed in a stepped sawtooth shape (hole saw shape) in the axial direction on the tip circumference of the drill head. The number of cutting edges is selected according to the hardness of the workpiece, the hole diameter to be processed, and the like. Moreover, when the taper-shaped relief is formed on the inner peripheral side of the tip cutting edge, the chips are fed toward the axial center of the drill head, so that the chip dischargeability is excellent.
Here, at least one chamfering hole is sufficient. Further, the chamfering hole is formed by being inclined from the lower end of the cylindrical portion of the drill head toward the shank side of the main body sleeve. Thereby, a chip is sent toward the through-hole of a main body sleeve, and it is excellent in the discharge property of a chip. The inclination angle α formed by the axis of the horizontal plane and the chamfering hole is preferably 30 to 60 degrees. As the inclination angle α becomes smaller than 30 degrees, the chamfering hole tends to incline and come into contact with the inner peripheral surface of the machined hole, and the width of the chamfering tends to be insufficient. As the inclination angle α becomes larger than 60 degrees, the chamfering hole There is a tendency that the holes are inclined to contact with the surface side of the workpiece and the chamfering depth is insufficient, which is not preferable.

  The invention according to claim 2 is the rotary hole drilling tool according to claim 1 or 2, wherein a tapered relief is formed on the inner peripheral side of the tip cutting edge.
  With this configuration, in addition to the operation of the first aspect, the following operation is provided.
(1) By forming a tapered relief on the inner peripheral side of the tip cutting edge, the chips are sent upward along the axis of the drill head, and the chip discharge performance is improved.

A third aspect of the present invention is the rotary drilling tool according to the second aspect, wherein the chamfering hole is formed on the rear side in the rotational direction of the inner hollow blade, and the axial center of the tip drill portion. And the axis of the chamfering hole are in a twisted position.
With this configuration, in addition to the operation of the second aspect, the following operation is provided .
(1) The edge of the chamfering hole is formed when the axis of the tip drill portion and the axis of the chamfering hole are in a twisted position, and the axis of the chamfering hole is inclined in the tangential direction of the outer periphery of the drill head. Can be brought into contact with the peripheral edge of the processed hole, and the machinability during chamfering can be improved.
(2) Since the shaft center of the tip drill portion and the shaft center of the chamfering hole are in a twisted position, and the shaft center of the chamfering hole is inclined with respect to the horizontal plane, chips generated during chamfering are It can feed toward the through-hole of the main body sleeve, can prevent clogging in the chamfering hole, and can improve chip discharge.
Here, it is preferable that the axis of the chamfering hole is drilled in a horizontal plane with an inclination angle β of 10 degrees to 30 degrees with respect to the axis of the tip drill portion and inclined to the tangential side of the outer periphery. As the inclination angle β in the horizontal plane of the chamfering hole becomes smaller than 10 degrees, the edge of the chamfering hole approaches an obtuse angle, the machinability at the time of chamfering tends to be lowered, and burrs tend to occur, and the inclination angle β As the angle becomes larger than 30 degrees, the edge of the chamfering hole becomes an acute angle, the amount of cutting becomes excessively large, the machinability tends to deteriorate, and damage such as chipping tends to occur, both of which are not preferable.
The inclination angle α formed between the horizontal plane and the axis of the chamfering hole is preferably 30 to 60 degrees as in the first aspect .
The axis of the chamfering hole and the axis of the chamfering hole are inclined by an inclination angle α with respect to the horizontal plane and an inclination angle β in the horizontal plane with respect to the axis of the tip drill part. The minds are not parallel and do not cross each other and are in a twisted position.

A fourth aspect of the present invention is the rotary drilling tool according to any one of the first to third aspects, wherein the inner peripheral surface of the drill head is expanded toward the body sleeve side. It has the structure provided with the part.
With this configuration, in addition to the operation of any one of claims 1 to 3, the following operation is provided.
(1) Since the inner peripheral surface of the drill head has a tapered portion that expands toward the main body sleeve side, the chips generated by the drill head and sent to the main body sleeve side are not easily clogged, and the chip discharge performance is improved. Can be improved.

According to a fifth aspect of the present invention, there is provided the rotary hole drilling device according to any one of the first to fourth aspects, wherein the internal thread part or the external thread part formed at the tip of the body sleeve, and the drill The head includes a male screw portion or a female screw portion that is formed at the lower end of the head and is screwed to the female screw portion or the male screw portion of the main body sleeve.
With this configuration, in addition to the operation described in any one of claims 1 to 4, the following operation is provided.
(1) By having a female screw part or male screw part formed at the tip of the main body sleeve and a male screw part or female screw part formed at the lower end of the drill head and screwed to the female screw part or male screw part of the main body sleeve, Since the main body sleeve and the drill head can be easily attached and detached, replacement when the drill head is damaged and cleaning of the main body sleeve and drill head are easy and excellent in maintenance.
(2) Since the main body sleeve and the drill head are detachable by the female screw portion and the male screw portion, they can be manufactured separately using materials suitable for each, and productivity and assemblability can be improved.
(3) Since the main body sleeve and the drill head are detachable by the female screw portion and the male screw portion, the drill head can be replaced according to the material of the workpiece, the hole diameter to be processed, etc., and versatility can be improved.
Here, the direction of the screw of the internal thread portion and the external thread portion formed in the main body sleeve and the drill head is formed in a direction in which the main body sleeve and the drill head are tightened with the rotation of the drill head during drilling. As a result, the main body sleeve and the drill head do not loosen or come off during drilling, and the safety and reliability are excellent.

The invention according to claim 6 of the present invention is the rotary drilling tool according to any one of claims 1 to 5, and is opposed to the upper end of the chip discharge port and the chip discharge port. It has the structure provided with the substantially arc-shaped discharge | emission guide part which connects the internal peripheral surface of the said through-hole.
With this configuration, in addition to the operation described in any one of claims 1 to 5, the following operation is provided.
(1) Since it has a substantially arc-shaped discharge guide portion that connects the upper end of the chip discharge port and the inner peripheral surface of the through hole facing the chip discharge port, The sent chips can be reliably guided toward the chip discharge port, and the chip discharge performance can be improved.
Here, the discharge guide portion may be disposed directly in the through hole of the main body sleeve, or may be formed at the end of the shank. When the discharge guide portion is formed at the end of the shank, it is easy to process and can be easily aligned and assembled when the shank is fitted to the main body sleeve, resulting in excellent productivity.

As described above, according to the rotary drilling tool of the present invention, the following advantageous effects can be obtained.
According to invention of Claim 1, it has the following effects.
(1) Since the drill head has a tip drill part, the positioning can be easily performed, and the drilling process can be performed at an accurate position by the inner drilling blade and the tip cutting edge using the tip drill part as a guide. It is possible to provide a rotary drilling tool excellent in productivity and productivity.
(2) The tip cutting edge is formed in a stepped shape in the axial direction on the tip circumference of the drill head, and the inner cut-out blade is connected to the base of the tip drill part, from the axis of the drill head toward the inner peripheral surface. By being formed, the outer periphery of the hole can be cut with the cutting edge of the tip, and the inside of the hole can be cut with the inner cut-off blade, so that no core residue or burrs are generated, and the roundness is high. It is possible to provide a highly reliable rotary drilling tool that can perform drilling.
(3) Since the inner drilling blade is formed continuously from the axial center of the tip drill portion toward the inner peripheral surface of the drill head, the tip drill portion is supported by the inner drilling blade. Therefore, it is possible to provide a rotary drilling tool excellent in processing stability and reliability, which can prevent the occurrence of shaft runout using the tip drill portion as a guide and can perform drilling with high accuracy.
(4) Since the drill head disposed at the tip of the main body sleeve has a chip discharge port that communicates with the through hole of the main body sleeve and opens on the side surface of the main body sleeve and is formed in a cylindrical shape, the main body sleeve Chips generated at the tip of the drill head can be sent to the through hole in the rear body sleeve and discharged from the chip discharge port, which can prevent chip clogging at the drill head. It is possible to provide a rotary drilling tool having excellent properties.
(5) Since the drill head has a chamfering hole drilled from the outer periphery of the lower end of the drill head to communicate with the through hole of the main body sleeve, the periphery of the hole machined by the chamfering hole can be chamfered at the end of drilling. Therefore, it is possible to provide a rotary punch having excellent functionality and productivity that does not require finishing with another tool or the like.
(6) Since the chamfering hole is formed in communication with the through hole of the main body sleeve, the chamfered chips can be sent to the through hole and discharged from the chip discharge port. It is possible to provide a highly reliable rotary drilling tool that can prevent generation.

According to invention of Claim 2, in addition to the effect of Claim 1, it has the following effects.
(1) A rotation hole that improves chip discharge by forming a tapered relief on the inner peripheral side of the cutting edge to feed chips upward along the axis of the drill head. A drilling tool can be provided.

According to invention of Claim 3, in addition to the effect of Claim 1 or 2 , it has the following effects.
(1) The edge of the chamfering hole is formed when the axis of the tip drill portion and the axis of the chamfering hole are in a twisted position, and the axis of the chamfering hole is inclined in the tangential direction of the outer periphery of the drill head. Can be brought into contact with the peripheral edge of the machined hole, and a rotary drilling tool excellent in machining stability that can improve the machinability during chamfering can be provided.
(2) Since the shaft center of the tip drill portion and the shaft center of the chamfering hole are in a twisted position, and the shaft center of the chamfering hole is inclined with respect to the horizontal plane, chips generated during chamfering are The chamfering hole can be fed toward the through-hole of the main body sleeve, and the chamfering hole is formed at the rear in the rotational direction of the inner cutting blade. It is possible to provide a rotary drilling tool excellent in reliability and stability capable of improving the waste discharging performance.

According to invention of Claim 4, in addition to the effect of any one of Claims 1 thru | or 3, it has the following effects.
(1) Since the inner peripheral surface of the drill head has a tapered portion that expands toward the main body sleeve side, the chips generated by the drill head and sent to the main body sleeve side are not easily clogged, and the chip discharge performance is improved. It is possible to provide a rotary drilling tool excellent in processing stability that can be improved.

According to invention of Claim 5, in addition to the effect of any one of Claims 1 thru | or 4, it has the following effects.
(1) By having a female screw part or male screw part formed at the tip of the main body sleeve and a male screw part or female screw part formed at the lower end of the drill head and screwed to the female screw part or male screw part of the main body sleeve, Since the main body sleeve and the drill head can be easily attached and detached, it is possible to provide a rotary drilling tool that is easy to replace when the drill head is broken and to clean the main body sleeve and the drill head and has excellent maintainability.
(2) Since the main body sleeve and the drill head are detachable by the female screw part and the male screw part, they can be manufactured separately using materials suitable for each, and a rotary drilling tool excellent in productivity and assembly is provided. be able to.
(3) Since the main body sleeve and drill head are detachable by the female screw part and the male screw part, a rotary drilling tool with excellent versatility that can replace the drill head according to the material of the workpiece, the hole diameter to be machined, etc. Can be provided.

According to invention of Claim 6, in addition to the effect of any one of Claims 1 thru | or 5, it has the following effects.
(1) Since it has a substantially arc-shaped discharge guide portion that connects the upper end of the chip discharge port and the inner peripheral surface of the through hole facing the chip discharge port, It is possible to provide a highly reliable rotary drilling tool capable of reliably guiding the sent chips toward the chip discharge port and improving chip discharge performance.

(Embodiment 1)
Hereinafter, the rotary drilling tool according to Embodiment 1 of the present invention will be described with reference to the drawings.
1 is an overall side view showing a rotary drilling tool in Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is rotation in Embodiment 1 of the present invention. 4 is a front view showing a drill head of a drilling tool, FIG. 4 is a sectional view taken along line BB in FIG. 2, FIG. 5A is a sectional view taken along line CC in FIG. 3, and FIG. ) Is a sectional view taken along line DD in FIG.
1 to 5, 1 is a rotary drilling tool in Embodiment 1 of the present invention, 2 is a cylindrical shank connected to a tool main body such as an electric drill or an air drill, and 2 a is a main body of the rotary drilling tool 1. An end fixing portion 2b of the shank 2 fitted in a through hole 3a drilled in parallel with the longitudinal direction of the axis of the sleeve 3 and fixed by a fixing screw 4 is provided at the tip of the end fixing portion 2a of the shank 2. An arc-shaped chip discharge guide portion, 3b is a slot-shaped chip discharge port that faces the discharge guide portion 2b and opens in the side surface of the main body sleeve 3, and 3c is formed at the tip of the main body sleeve 3. The internal thread part 5b by which the external thread part 5a formed by the lower end of the drill head 5 was screwed together, and 5b are the tip drills arrange | positioned so that a front-end | tip may protrude in the axial center of the drill head 5 formed cylindrically. And 5c are connected to the base of the tip drill portion 5b. Two inner punching blades 5d formed from the axial center of the end drill portion 5b toward the inner peripheral surface of the cylindrical portion 5e of the drill head 5 are stepped in the axial direction on the tip circumference of the drill head 5. Two cutting edges 5f formed with a tapered relief 5d ′ (FIG. 5A) formed on the inner peripheral surface, 5f from the outer periphery of the lower end of the cylindrical portion 5e of the drill head 5 to the through hole of the body sleeve 3. The shaft center is drilled at an inclination angle α (FIG. 2) with respect to the horizontal plane and an inclination angle β (FIG. 4) within the horizontal plane with respect to the axis of the tip drill portion 5b so as to communicate with 3a. The two chamfering holes 5g are taper portions on the inner peripheral surface of the drill head 5 that is expanded toward the main body sleeve 3 at the lower portion of the cylindrical portion 5e.

The main body sleeve 3 uses a pipe made of stainless steel or the like, and the inner peripheral surface of the through-hole 3a is polished smoothly to improve the chip dischargeability.
Further, the upper end of the discharge guide portion 2b and the upper end of the chip discharge port 3b are made to substantially coincide with each other so that the chips are reliably guided to the chip discharge port 3b. The chip discharge port 3b is formed in a long hole shape to increase the opening area, thereby improving chip discharge performance.
As the material of the drill head 5, SK material which is carbon tool steel, SKS material of alloy tool steel, high-grade high alloy HSS, cemented carbide and the like are used, and the wear resistance is improved. The outer periphery of the tip of the drill head 5 was polished to prevent burrs.
Since the tip cutting edge 5d is formed in a stepped shape (hole saw shape) in the axial direction on the tip circumference of the drill head 5, drilling can be efficiently performed by scooping the hole edge. Further, by forming a tapered relief 5d ′ on the inner peripheral side of the tip cutting edge 5d, the chips can be sent upward along the axis of the drill head 5 to improve the chip dischargeability. It was.

The inclination angle α formed by the horizontal plane and the axis of the chamfering hole 5f was formed to be 30 to 60 degrees. As the inclination angle α becomes smaller than 30 degrees, the chamfering hole 5f tends to come into contact with the inner peripheral surface of the machined hole and the width of the chamfering tends to be insufficient, and as the inclination angle α becomes larger than 60 degrees, the chamfering is performed. It has been found that the working hole 5f is inclined to contact with the surface side of the workpiece and the chamfering depth tends to be insufficient.
Further, the axis of the chamfering hole 5f was drilled in a horizontal plane with an inclination angle β of 10 degrees to 30 degrees with respect to the axis of the tip drill part 5b in the tangential side of the outer periphery. As the inclination angle β in the horizontal plane of the chamfering hole 5f becomes smaller than 10 degrees, the edge of the chamfering hole 5f approaches an obtuse angle and the machinability at the time of chamfering is liable to be reduced, and burrs tend to occur. As the angle β becomes larger than 30 degrees, it has been found that the edge of the chamfering hole 5f becomes an acute angle, the cutting amount becomes too large, the machinability tends to be lowered, and breakage such as chipping tends to occur. .
Since the axis of the chamfering hole 5f is inclined with respect to the horizontal plane at an inclination angle α (FIG. 2) and with respect to the axis of the tip drill portion 5b at an inclination angle β in the horizontal plane (FIG. 4), the tip drill Since the shaft center of the portion 5b and the shaft center of the chamfering hole 5f are not parallel and do not intersect with each other and are in a twisted position, the chip discharge performance is excellent.
In the present embodiment, the inner cut-off blade 5c is a straight blade, but when it is a twisted blade, the cutting performance can be further improved as compared with the straight blade, and the workability is excellent.
In addition, the internal thread portion 3c is formed on the main body sleeve 3 and the external thread portion 5a is formed on the drill head 5, and the main body sleeve 3 and the drill head 5 are screwed together. However, the main body sleeve 3 and the drill head 5 may be integrally formed. .

A method of using the rotary drilling tool in the first embodiment configured as described above will be described.
1 to 5, first, the shank 2 of the rotary punch 1 is connected to a tool body such as an electric drill or an air drill (not shown).
Drilling is performed by aligning the tip drill portion 5b of the drill head 5 with the drilling position. At this time, if a substantially circular concave portion is formed in advance at the drilling position with a punch or the like, alignment can be easily performed.
When the rotary drill 1 is rotated, the tip drill portion 5b of the drill head 5 serves as a guide and enters the workpiece. Further, by pushing the rotary drilling tool 1, the outer periphery of the hole is cut by two tip cutting edges 5 d formed in steps in the axial direction on the tip circumference of the drill head 5. At the same time, the inside of the hole is cut by the two inner cut-out blades 5c that are connected to the base of the tip drill portion 5b and are formed from the axial center of the cylindrical portion 5e of the drill head 5 toward the inner peripheral surface. As a result, drilling with no core residue is performed with high accuracy without causing shaft blurring.
Finally, the peripheral edge of the hole processed by the two chamfering holes 5f drilled on the outer periphery of the lower end of the cylindrical portion 5e of the drill head 5 is chamfered, and the processing ends.
Since the processed hole has no burr and the peripheral edge is chamfered, the lid for closing the hole can be easily and reliably fitted.

Since the rotary drilling tool of Embodiment 1 is configured as described above, it has the following action.
(1) Since the drill head 5 has the tip drill portion 5b, positioning can be easily performed, and drilling is performed at an accurate position by the inside drilling blade 5c and the tip cutting blade 5d using the tip drill portion 5b as a guide. Can be done.
(2) The tip cutting edge 5d is formed in a stepped shape in the axial direction on the circumference of the tip of the drill head 5, and the inner cut-off blade 5c is connected to the base of the tip drill portion 5b so as to be inward from the axis of the drill head 5. By being formed toward the peripheral surface, the outer periphery of the hole can be cut with the tip cutting edge 5d, and the inside of the hole can be cut with the inner cut-off blade 5c. Therefore, drilling with high roundness can be performed.
(3) Since the inner drilling blade 5c is connected to the base of the tip drill portion 5b and formed from the axial center of the tip drill portion 5b toward the inner peripheral surface of the cylindrical portion 5e of the drill head 5, the inner drilling blade The tip drill portion 5b can be supported by 5c, and the drill head 5 can be guided by the tip drill portion 5b to prevent the occurrence of shaft blurring, so that accurate drilling can be performed.
(4) A drill head 5 that has a chip discharge port 3b that communicates with the through-hole 3a of the main body sleeve 3 and opens on the side surface of the main body sleeve 3 and is disposed at the tip of the main body sleeve 3 is formed in a cylindrical shape. Therefore, chips generated by the drill head 5 at the tip of the main body sleeve 3 can be sent to the through hole 3a of the rear main body sleeve 3 and discharged from the chip discharge port 3b. Occurrence of clogging can be prevented, and chip discharge is excellent.
(5) Since there is a chamfering hole 5f drilled from the outer periphery of the lower end of the drill head 5 to the through hole 3a of the main body sleeve 3, the peripheral edge of the hole machined by the chamfering hole 5f at the end of drilling Can be chamfered, and it is not necessary to perform finishing using another tool or the like, thereby improving workability.
(6) Since the chamfering hole 5f communicates with the through hole 3a of the main body sleeve 3, the chamfered chips can be sent to the through hole 3a and discharged from the chip discharge port 3b. It is possible to prevent the occurrence of chip clogging.
(7) The axial center of the tip drill portion 5b and the axial center of the chamfering hole 5f are in a twisted position, and the axial center of the chamfering hole 5f is inclined at an inclination angle β in the tangential direction of the outer periphery of the drill head 5. Thus, the edge of the chamfering hole 5f can be brought into contact with the peripheral edge of the processed hole, and the machinability during chamfering can be improved.
(8) Since the axial center of the tip drill portion 5b and the axial center of the chamfering hole 5f are in a twisted position, and the axial center of the chamfering hole 5f is inclined with respect to the horizontal plane at an inclination angle α, The generated chips can be sent toward the through hole 3a of the upper body sleeve 3, the generation of chip clogging in the chamfering hole 5f can be prevented, and the chip discharge performance can be improved. .
(9) Since the inner peripheral surface of the drill head 5 has a taper portion 5g that expands toward the main body sleeve 3 side, chips generated by the drill head 5 and sent to the main body sleeve 3 side are hardly clogged. It is possible to improve waste dischargeability.
(10) The main body sleeve 3 has a female screw portion 3c formed at the tip of the main body sleeve 3 and a male screw portion 5a formed at the lower end of the drill head 5 and screwed to the female screw portion 3c of the main body sleeve 3. Since the drill head 5 can be easily attached and detached, replacement when the drill head 5 is damaged and cleaning of the main body sleeve 3 and the drill head 5 are easy and excellent in maintenance.
(11) Since the main body sleeve 3 and the drill head 5 are detachable by the female screw portion 3c and the male screw portion 5a, they can be manufactured separately using materials suitable for each, and productivity and assemblability can be improved. .
(12) Since the main body sleeve 3 and the drill head 5 are detachable by the female screw portion 3c and the male screw portion 5a, the drill head 5 can be replaced according to the material of the workpiece, the hole diameter to be processed, etc., and versatility is improved. be able to.
(13) Since it has a substantially arc-shaped discharge guide portion 2b that connects the upper end of the chip discharge port 3b and the inner peripheral surface of the through hole 3a facing the chip discharge port 3b, the main body generated by the drill head 5 The chips sent to the through hole 3a of the sleeve 3 can be reliably guided toward the chip discharge port 3b, and the chip discharge performance can be improved.
(14) By forming a tapered relief 5d ′ on the inner peripheral side of the tip cutting edge 5d, chips can be sent along the axis of the drill head 5 to the through hole 3a of the upper body sleeve 3. In addition, chip discharge performance can be improved.

  The present invention can be easily mounted and used on existing tools such as electric drills and air drills, and is excellent in versatility. It has a simple structure and does not generate burrs or core residue. The hole can be drilled with high reliability and workability, and the edge of the hole processed after drilling can be chamfered at the same time, providing excellent functionality and productivity, and excellent chip discharge. Can be used continuously, can provide a rotary drilling tool with excellent reliability and maintainability, and is made of soft materials such as synthetic resin and rubber, especially for synthetic resin sashes It can be suitably used as a rotary drilling tool suitable for drilling a molded article.

Whole side view which shows the rotary punch in Embodiment 1 of this invention AA line sectional view in FIG. The front view which shows the drill head of the rotary drilling tool in Embodiment 1 of this invention BB sectional view in FIG. (A) CC sectional view in FIG. 3 (b) DD sectional view in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating hole drill 2 Shank 2a End fixing | fixed part 2b Ejection guide part 3 Main body sleeve 3a Through-hole 3b Chip discharge port 3c Female thread part 4 Fixing screw 5 Drill head 5a Male thread part 5b Tip drill part 5c Inner cutting edge 5d Tip Cutting edge 5d 'Escape 5e Cylindrical part 5f Chamfering hole 5g Taper part α, β Inclination angle

Claims (6)

A shank connected to a tool main body such as an electric drill or an air drill, a cylindrical main body sleeve having a through-hole drilled in parallel with the longitudinal direction of the shaft center, and connected to the shank; A drill head including a chip discharge port that communicates with the through-hole and opens on a side surface of the main body sleeve, and a cylindrical portion that is disposed at the tip of the main body sleeve and has a smaller diameter than the outer diameter of the main body sleeve. And the drill head is provided with a tip drill portion and an inner hollow formed continuously from the shaft center of the tip drill portion toward the inner peripheral surface of the drill head. A blade, a tip cutting edge formed in a step shape in the axial direction on the tip circumference of the drill head, and a hole drilled from the outer periphery of the lower end of the cylindrical portion of the drill head to the through hole of the body sleeve Established Rotation drilling tool, characterized in that it includes a hole for taking the. The rotary drilling tool according to claim 1, wherein a tapered relief is formed on an inner peripheral side of the tip cutting edge . The chamfering hole is formed on a rear side in the rotation direction of the inner hollow blade, and the axial center of the tip drill portion and the axial center of the chamfering hole are in a twisted position. The rotary drilling tool according to 1 or 2 .   The rotary drilling tool according to any one of claims 1 to 3, wherein an inner peripheral surface of the drill head has a tapered portion that expands toward the main body sleeve side.   A female screw part or a male screw part formed at the tip of the main body sleeve; and a male screw part or a female screw part formed at the lower end of the drill head and screwed to the female screw part or the male screw part of the main sleeve. The rotary drilling tool according to any one of claims 1 to 4, wherein the rotary drilling tool is provided.   6. The discharge guide portion according to claim 1, further comprising an approximately arc-shaped discharge guide portion that connects an upper end of the chip discharge port and an inner peripheral surface of the through-hole facing the chip discharge port. The rotary drilling tool according to item 1.