JPH0811096A - Bowling cutter - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a boring cutter that can easily attach and detach the shank (adapter) and the blade body and can reliably connect the blade body and the shank (adapter). . [Structure] The boring cutter BC1 has a cylindrical blade body 10.
, A shank 20, and an adapter 30 that connects the tubular blade body 10 and the shank 20. The adapter 30 has a structure in which the tightening ring 33, the first plate 31, and the second plate 32 are assembled via the shank 20, and by rotating the tightening ring 33, the first plate 31 and the second plate 32
And are in close proximity. Also, the adapter 30 has both plates 31,
A split ring 34 is provided on the peripheral edge of 32, and the split ring 34 expands in diameter when both plates 31 and 32 come close to each other, and strongly presses the inner wall of the tubular blade body 10.
0 and the shank 20 are connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boring cutter used for forming a desired hole in an object to be drilled, and more particularly to a boring cutter to which a shank and a cylindrical blade can be attached and detached. .

[0002]

2. Description of the Related Art Conventionally, various boring cutters used for forming holes having a desired diameter have been put into practical use in objects to be perforated such as concrete walls, synthetic resin walls, and wood walls. These boring cutters are used, for example, when forming a pipe hole through which a pipe for an air conditioner is inserted in a concrete wall of a house.

Generally, such a boring cutter is provided with a center drill for determining a center and a cylindrical blade body with a bottom. Initially, the blade body and the shank were integrally formed. By the way, in the boring cutter, every time when drilling for the length of the blade body, shavings generated from the body to be drilled are accumulated inside the blade body along with the drilling. Needs to be removed.

However, since the blade body and the shank are integrally formed, it is not always easy to remove the shavings accumulated inside the blade body, and in particular, it is sandwiched between the center drill and the blade body. There is a problem that it is extremely difficult to remove the shavings that have been removed.

Therefore, there has been proposed a boring cutter in which the shank and the blade are formed as separate parts, the blade can be attached to and detached from the shank, and the shavings accumulated inside the blade can be easily removed.

This removable boring cutter is shown in FIG.
This will be described with reference to 0. As shown in FIG. 10, in this type of boring cutter BC2, the shank 110 and the cylindrical blade body 120 are connected via an adapter 100.

The adapter 100 has a shank 110.
A disc-shaped moving plate 101 that is screwed to the disc-shaped movable plate 101 and a disc-shaped movable plate 101 that supports one open end (a side where the blade portion is not formed) of the tubular blade body 120 and is fixed in position relative to the shank 110. Fixed plate 102 and moving plate 1
01 and the fixed plate 102, the split ring 103 is expanded in diameter.

At the center of the moving plate 101, there is formed a bearing portion having a thread groove to be screwed into the screw thread of the shank 110. The moving plate 101 has a spanner engaged with the rotary operation portion 111. By rotating the shank 110 clockwise, the shank 110 is screwed from the tip of the shank 110 toward the center of the shank 110. Also, the fixed plate 1
A bearing portion having an opening diameter slightly larger than the diameter of the shank 110 is formed in the central portion of 02, and the fixed plate 102 does not change its position even when the shank 110 rotates. Furthermore, the peripheral edge of each plate 101, 102 is formed in a tapered shape, and each plate 10
When the plates 1 and 102 are separated from each other, a groove is formed in the peripheral portion, and as the plates 101 and 102 are close to each other, the groove formed in the peripheral portion gradually becomes shallower. Furthermore, the split ring 103 has a part of the ring cut, and its diameter is expanded by being pressed from the inside.

In the removable boring cutter BC2 having the above-described structure, when the shank 110 and the blade body 120 are connected via the adapter 100, first, one open end of the cylindrical blade body 120 (the blade portion The adapter 100 to which the shank 110 is attached is arranged inside the formation side). Next, one spanner is used to immobilize the bearing portion of the fixed plate 102, and another spanner is used to rotate the rotary operation portion 111 of the shank 110 clockwise. Here, the fixed plate 102 and the movable plate 101 are the fixed plate 10
The engaging protrusions of No. 2 and the engaging holes of the moving plate 101 are engaged with each other to integrally rotate.

Therefore, the movable plate 101 is fixedly held by the spanner of 1 through the fixed plate 102, and when the shank 110 is rotated rightward, the movable plate 101 is screwed toward the center of the shank 110 and fixed. It gradually approaches the plate 102. Then, as the plates 101, 102 come closer to each other,
The groove formed in the peripheral portion gradually becomes shallower, and the split ring 103 accommodated in the groove is pressed and expanded in diameter.

When the split ring 103 is expanded in diameter inside the blade 120 in this way, the blade 120 is pressed from the inside by the split ring 103 and is connected to the adapter 100 to which the shank 110 is mounted.

On the other hand, when the blade 120 and the shank 110 are separated, the opening diameter of the split ring 103 is reduced to the original opening diameter by rotating the shank 110 counterclockwise, and the adapter 100 is removed from the blade 120. It comes off and is separated from the shank 110. By loosening the adapter 100 and separating the blade 120 and the shank 110 in this manner, there is an advantage that the shavings accumulated inside the blade 120 can be easily removed.

[0013]

However, in the conventional removable boring cutter BC2, as described above, the split ring 103 is expanded by the cooperation of the movable plate 101 and the fixed plate 102, and the expanded split ring is expanded. 10
3, the adapter 100 and the blade body 120 were connected only by pressing the inside of the blade body 120.

In such a boring cutter BC2,
In order to prevent the blade body 120 and the adapter 100 from coming off due to the rotation and vibration generated in the shank 110 during the drilling work, the shank 110 is tightly tightened by using two spanners to move the movable plate 101 and the fixed plate 10.
It is necessary to bring the split ring 103 into close contact with the blade body 120 and to firmly adhere the split ring 103 to the inside of the blade body 120.

Therefore, a large force is required and required when the adapter 100 is tightened to connect the shank 110 and the blade body 120 and when the adapter 100 is loosened to separate the shank 110 and the blade body 120. It was necessary to use a tool in order to realize a large force. Therefore, the work of connecting and separating the blade body 120 and the shank 110 becomes extremely complicated, and the blade body 12
There is a problem that the blade body 120 and the shank 110 cannot be easily attached and detached while having a structure in which the 0 and the shank 110 are detachable.

Further, the blade body 120 and the shank 110 can be easily carried out.
The fact that it is not possible to attach and detach the blade 120
This means that the shavings accumulated inside cannot be easily removed, and there is a problem in that during the drilling work, it takes time to remove the shavings and the efficiency of the drilling work cannot be improved.

Further, the movable plate 101 and the shank 1 which are movable when the blade body 120 and the shank 110 are attached and detached.
Since the shavings have a structure in which they directly contact the threaded portion with the screw 10, if fine shavings enter the threaded portion between the moving plate 101 and the shank 110, it is extremely difficult to remove the shavings. Had a serious problem.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a boring cutter capable of easily attaching and detaching a shank (adapter) and a blade body. . Moreover, it aims at providing the boring cutter which can connect a blade and a shank (adapter) reliably.

[0019]

In order to achieve the above object, a boring cutter according to the present invention has a cylindrical blade body having a bottomless cylindrical shape and a blade portion formed at the periphery of one opening. A boring cutter equipped with a shank that is mounted on a drive device and that transmits a driving force to the tubular blade, and an adapter that connects the tubular blade and the shank, wherein the adapter is formed at the center thereof. First done
A disk-shaped first plate attached to the shank via the attachment part, a second plate annularly attached to the shank via an attachment hole formed in the center thereof, and formed in the center thereof A tightening ring that is attached to the shank so as to be able to move forward and backward through the attached second attached portion and that brings the second plate closer to the first plate; and a first ring and a second plate The shank is provided with a diameter-expanding ring that is arranged along a peripheral edge and expands in diameter as the first plate and the second plate come close to each other. And a second attachable portion movably attached to the vicinity of a central portion of the first attachable portion for detachably attaching the second attachable portion.
It is provided with a structure in which an attachment portion is formed.

At this time, the first plate and the second plate
It is desirable that at least one of the peripheral edges of the plate is tapered. Further, it is preferable that an engagement portion with which the diameter expansion ring is engaged is formed on an inner wall surface of the tubular blade body. further,
It is preferable that a concave peripheral portion is formed on the periphery of the second attachment portion of the tightening ring.

[0021]

In the boring cutter according to the present invention having the above-mentioned structure, the adapter is fixed to the tubular blade body by disposing the adapter inside the tubular blade body and advancing the tightening ring toward the tip of the shank. At the same time, the shank and the tubular blade are connected.

That is, when the tightening ring advances toward the shank tip, the tightening ring presses against the second plate mounted on the shank, and the second plate contacts the first plate attached to the shank tip. Move closer towards. In this way, as the first plate and the second plate are relatively close to each other, the diameter-enlarging rings arranged along the peripheral edges of both plates expand in diameter and come into contact with the inner wall of the tubular blade. When the tightening ring continues to advance even after the expanding ring contacts the inner wall of the tubular blade, the expanding ring eventually presses the inner wall of the cylindrical blade strongly, and the tubular blade and the adapter are separated from each other. It will be fixed.

At this time, if either one of the peripheral portions of the first plate or the second plate, or the peripheral portion of both plates is formed in a tapered shape, the two plates are moved closer to each other as they come closer to each other. The width of the groove formed by the peripheral edge portion of N is narrowed, and the expanded ring is pressed outward in the radial direction. As a result, the diameter-enlarging ring expands in diameter and comes into contact with and presses against the inner wall of the tubular blade. Also,
When the engagement portion is formed on the inner wall surface of the tubular blade,
The enlarged diameter expanding ring engages with the engaging portion, and the tubular blade body is reliably prevented from shifting in the axial direction of the shank.

In this way, after the shank and the cylindrical blade body are connected via the adapter, the shank is mounted on the drive unit to perform the punching operation. When the drive device is activated, the shank rotates and the tubular blade connected to the shank via the adapter rotates. When the center drill or the center pin is attached to the shank tip, the center drill or the center pin also rotates at the same time. Here, when the concave peripheral portion is formed in the annular portion of the tightening ring, the moment of inertia generated with the rotation of the tightening ring becomes small.

In such a state, first, the center drill or the center pin is brought into contact with the body to be drilled to determine the drilling position. When the boring cutter is pressed toward the body to be drilled as it is, when the center drill is provided, the body to be drilled is drilled, and when the center pin is provided, for example, an elastic body such as a spring. By contracting, the tubular blade comes into contact with the body to be drilled.

The cylindrical blade body that is in contact with the body to be perforated cuts the body to be perforated with the diameter of the cylinder by means of the blade portion formed on the peripheral edge of the opening, and perforates the body. Eventually, when the perforation progresses by the length of the tubular blade, shavings accumulate inside the tubular blade, and it becomes impossible to continue the drilling work.
The work of extracting the blade from the body to be punched and removing the shavings accumulated in the blade is performed.

To remove the shank (adapter) from the tubular blade, the above-described operation for connecting the tubular blade and the adapter may be carried out in the reverse order. The blade and the shank are separated, and the shavings accumulated inside the tubular blade can be easily removed.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a boring cutter will be described below with reference to the drawings.

First, the structure of the boring cutter BC1 will be described with reference to FIGS. The boring cutter BC includes a cylindrical blade body 10 for cutting a body to be drilled, a shank 20 for transmitting a driving force of a driving device (not shown) such as an electric drill to the cylindrical blade body 10, and the cylindrical blade body 10. An adapter 30 for connecting the shank 20 and the shank 20 is provided.

The tubular blade body 10 is made of a metal material and has a bottomless tubular shape, and an annular blade portion 12 attached to the peripheral edge of the opening on the front end side of the main body 11 when viewed from the front. It consists of An adapter mounting portion 13 that defines the mounting position of the adapter 30 is formed on the base end side of the main body 11, and the opening diameter of the adapter mounting portion 13 is set to the main body 11 side.
The mounting position of the adapter 30 is determined by making it larger than the opening diameter of the other part.

Further, as shown in FIG. 3, the adapter mounting portion 13 is formed with a locking pin receiving portion 13a for receiving a locking pin 38 of the second plate 32 described later. further,
Inside the adapter mounting portion 13, along the circumferential direction of the inner wall,
An engagement groove portion 13b with which an engagement protrusion 34a of the split ring 34 described later is engaged is formed in a band shape. Furthermore,
In the blade portion 12, first blades 12a and second blades 12b having blades of different shapes are alternately arranged at 90 degree intervals.

The adapter 30 includes a first plate 31, a second plate 32, and a tightening ring 33 made of a metallic disc-shaped material, a split ring 34 obtained by cutting a part of the metallic ring, and a first plate 31. It is a connecting component in which a corrugated washer 35 interposed between the second plate 32 and the second plate 32 is assembled.

The first plate 31 is composed of a cylindrical first mounting portion 31a and an annular first annular portion 31b formed around the first mounting portion 31a. And
A thread groove is formed on the inner wall of the first mounting portion 31a and is mounted on the first plate mounting portion of the shank 20 described later. Further, the first annular portion 31b is formed with two first locking holes 31c at positions facing each other, and the peripheral portion of the first annular portion 31b is formed in a tapered shape.

The second plate 32 is composed of a second mounting portion 32a formed in a tubular shape, and an annular second annular portion 32d formed around the second mounting portion 32a. And the 2nd mounting part 32a is comprised from the large diameter part 32b which accommodates the 1st mounting part 31a, and the small diameter part 32c through which the 2nd plate mounting part of the shank 20 penetrates. A second locking hole 32e is formed in the second annular portion 32d similarly to the first locking hole 31c, and a locking pin 37 is inserted into each second locking hole 32e. In addition, the peripheral portion is formed in a tapered shape. Furthermore, the second
Two third locking holes 32f are formed extending in the radial direction at positions facing each other on the peripheral surface of the annular portion 32d. A locking pin 38 is fitted in the third locking hole 32f, and the head portion of the locking pin 38 projects from the second annular portion 32d and is received by the locking pin receiving portion 13a of the adapter mounting portion 13.

The tightening ring 33 comprises a cylindrical third mounting portion 33a and an outer peripheral portion having two grooves 33b formed around the third mounting portion 33a. A thread groove is formed on the inner wall of the third mounting portion 33a, and the third mounting portion 33a is mounted on the tightening ring mounting portion 24 of the shank 20 described later so as to be movable back and forth.

The split ring 34 is an elastic metal ring which is arranged in a groove formed when the first plate 31 and the second plate 32 each having a tapered peripheral edge are combined with each other. It is a ring with a triangular cross section that can be expanded in diameter in the direction from the outer peripheral surface to the inner peripheral surface. Also,
Engagement protrusions 34a that engage with the engagement groove portions 13b of the adapter mounting portion 13 are formed on the outer peripheral surface.

The corrugated washer 35 is a washer having an elastic action, which facilitates the separation between the first plate 31 and the second plate 32 which are in close contact with each other and prevents the tightening ring 33 from loosening. Further, a washer 36 is also provided at the joint between the second plate 32 and the tightening ring 33 to facilitate the separation between the closely attached second plate 32 and the tightening ring 33. The washer 36 is preferably made of metal or synthetic resin.

As shown in FIG. 6, the shank 20 is made of one metal rod-shaped member, and the mounted portion 21 to be inserted and mounted in the mounting portion of the drive device and the first mounting portion 3 of the first plate 31.
A first plate mounting portion 22 to which 1a is mounted and a second plate mounting portion 23 to which the second mounting portion 32a of the second plate 32 is mounted are formed. Further, the shank 20 is formed with a tightening ring mounting portion 24 to which the third mounting portion 33a of the tightening ring 33 is mounted. Further, the shank 20 is formed with a center drill fixing part 25 for fixing the center drill 40 between the tightening ring mounting part 24 and the mounted part 21.

Further, a center drill mounting hole 26 for mounting the center drill 40 is formed in the center of the tip surface of the shank 20 from the first plate mounting portion 22 to the center drill fixing portion 25.

The first plate mounting portion 22 has the shank 20.
Is formed in a hollow columnar shape at the tip end portion thereof, and a screw thread that is screwed into the screw groove of the first mounting portion 31a is formed on the outer peripheral portion thereof. In addition, the second plate mounting portion 23
Is formed in a hollow cylindrical shape at a position adjacent to the first plate mounting portion 22 and has a diameter of the first plate mounting portion 22.
Is formed larger than the diameter of the. Further, no thread is formed on the outer peripheral portion of the second plate mounting portion 23.

Further, the tightening ring mounting portion 24 is formed in a hollow cylindrical shape at a position adjacent to the second plate mounting portion 23, and its diameter is formed larger than the diameter of the second plate mounting portion 23. There is. The tightening ring 3 is attached to the outer peripheral portion of the tightening ring mounting portion 24.
A screw thread that is screwed into the screw groove of No. 3 is formed.

The center drill fixing part 25 is formed in a hollow conical shape with a part cut away at a position adjacent to the tightening ring mounting part 24, and the long side (diameter) thereof is the diameter of the tightening ring 33. And the shorter side is smaller than the diameter of the tightening ring 33. A screw hole 25 for receiving a fixing screw for fixing the center drill 40 is formed on one outer peripheral surface in the long side direction.
a is formed to extend in the radial direction.

The mounted part 21 is a center drill fixing part 25.
Is formed in a columnar shape toward the base end of the shank 20. Further, if the circular cross section is left as it is, it tends to idle when mounted on the drive device, so three circumferential portions are flattened along the longitudinal direction of the mounted portion 21 to form a modified hexagonal cross section.

Next, the operation of the boring cutter BC1 according to this embodiment having the above structure will be described with reference to FIGS. First, a case where the cylindrical blade body 10 and the shank 20 are connected via the adapter 30 will be described.

First, the assembling of the adapter 30 will be described. The tightening ring 33 is passed from the tip of the shank 20 and is positioned at the upper end of the tightening ring mounting portion 24 of the shank 20. Then, by rotating the tightening ring 33, the tightening ring mounting part 24 and the third mounting part 33a of the tightening ring 33 are screwed together, and the tightening ring 33 is moved to the lowermost end of the tightening ring mounting part 24.

Subsequently, the washer 36 is passed through, and the washer 36 is placed on the upper surface of the tightening ring 33, and then the second plate 32 is passed through from above. Here, the second mounting portion 3 of the second plate 32
Since neither the groove 2a nor the thread is formed in the second plate mounting portion 23 of the shank 20, the second plate 32 is arranged on the second plate mounting portion 23 as it is.

Next, the corrugated washer 35 is passed through, and the split ring 34 is arranged on the tapered portion of the second plate 32. Then, the first plate 31 is passed through, and at this time, the respective locking pins 37 inserted into the respective second locking holes 32e of the second plate 32 and the respective first locking holes of the first plate 31. The first plate 31 is passed through so that 31c and 31c are engaged with each other. Then, when the first plate 31 and the second plate 32 are combined, the first plate 31 is rotated and the first plate mounting portion 22 of the shank 20 and the first mounting portion 31a of the first plate 31 are screwed together. Let Then, the lower surface of the first plate 31 is locked to the end surface of the second plate mounting portion 23 of the shank 20, and the first plate 31
This work is finished when is unable to rotate.

The manner in which the second plate 32 approaches the first plate 31 in the adapter 30 in the combined state will be described below with reference to FIGS. 7 and 8. 7 and 8, for convenience of explanation,
The tubular blade 10 is omitted.

As shown in FIG. 7, although the first plate 31 and the second plate 32 are in a combined state, the corrugated washer 35 interposed between the plates 31 and 32 causes the plates 31 and 32 to be combined. Are separated from each other. Therefore, the groove formed by the peripheral portions of the plates 31 and 32 formed in a tapered shape is wide,
In the deep state, the split ring 34 is the first plate 3
It is housed in the same plane as the outer peripheral surfaces of the first and second plates 32.

Here, the inner peripheral diameter of the adapter mounting portion 13 of the tubular blade 10 is determined by the first plate 31 and the second plate 3.
Since it is formed to be slightly larger than the outer peripheral diameter of 2, the adapter 30 can be easily fitted into the tubular blade 10.

When the adapter 30 is fitted into the cylindrical blade 10, the locking pin 38 provided in the third locking hole 32f of the second plate 32 and the locking pin receiving portion 13a of the adapter mounting portion 13 are fitted. And so that they engage with each other. When the tightening ring 33 is rotated in this state, the tightening ring 33 is screwed toward the tip of the shank 20 and presses the second plate 32 from the shank 20 proximal end side. The second plate 32 thus pressed is movable with respect to the shank 20, so that the tightening ring 3
3 moves toward the tip of the shank 20, and gradually approaches the first plate 31 attached to the tip of the shank 20.

Then, in FIG. 7 mentioned above, both plates 31, 3 are
The groove that was formed wide and deep by the peripheral edge of 2
As shown in FIG. 8, the width gradually changes so that the width becomes shallower. Further, the corrugated washer 35 also contracts when pressed. Along with this, the inner peripheral surface of the split ring 34 is pressed outward in the radial direction, and the diameter thereof gradually decreases. Therefore, the split ring 34 is provided in the first plate 3
The first and second plates 32 are exposed to the outside of the outer peripheral surface, come into contact with the inner wall of the tubular blade 10 (the inner wall of the adapter mounting portion 13), and eventually press the inner wall of the tubular blade 10. At this time, the engagement protrusion 34a of the split ring 34 is engaged with the engagement groove portion 13b of the adapter mounting portion 13, and the tubular blade 1
0 and the adapter 30 are prevented from shifting in the axial direction of the shank 20.

Then, when the split ring 34 is expanded on the inner wall of the adapter mounting portion 13 to the maximum diameter, the tightening ring 33 becomes unrotatable due to its reaction force, and the attachment of the adapter 30 to the tubular blade 10 is completed. . In this attachment process, it is not necessary to use a tool, and the attachment of the adapter 30 to the tubular blade body 10 is completed easily and quickly.

The boring cutter BC1 assembled in this manner is attached to a drive device (not shown), for example, an electric drill, via the mounted portion 21 of the shank 20, and the center drill 40 is attached to the center drill mounting hole 2 of the shank 20.
6 and the center drill fixing portion 25 is fixed with a fixing screw to start the drilling work.

First, in order to determine the punching position, the object to be punched,
For example, the center drill 40 is brought into contact with the drilling center of the wood material wall to determine the center position, and the electric drill is activated. Then, the driving force of the electric drill is transmitted to the cylindrical blade body 10 and the center drill 40 via the shank 20, and both start rotating. At this time, the outer periphery of the tightening ring 33 is 2
Since the groove of the book is formed and the weight is reduced, the torque required to start the rotation becomes small, and the tightening ring 3
The rotation moment generated in 3 becomes small.

When the boring cutter BC1 is pressed against the body to be drilled while the center drill 40 is in contact with the body to be drilled, the center drill 40 starts drilling and eventually the blade portion 12 of the tubular blade body 10 is drilled. Contact the body. The tubular blade 10 that abuts the body to be drilled is the first blade 1 provided on the blade portion 12.
By the cooperation of 2a and the second blade 12b, the object to be perforated is cut and perforated in the size of its cylindrical diameter.

At the time of this perforation, shavings inside the cylindrical blade body 10 accumulate inside the cylindrical blade body 10, so that the cylindrical blade body 1
After drilling the length of 0, the drilling work cannot be performed. At this time, the work of extracting the tubular blade 10 from the body to be punched and removing the shavings accumulated inside the tubular blade 10 is performed. At this time, the center drill 4
The shavings sandwiched between 0 and the tubular blade 10 are difficult to remove unless the tubular blade 10 and the adapter 30 (shank 20) are separated.

Therefore, in the conventional case, it was necessary to perform the separating work by using the tools one by one, but in the boring cutter BC1 according to the present embodiment, the tightening ring 33 is rotated by hand in the direction opposite to the assembling. By doing so, separation is easily performed.

This separation work is performed by reversing the above-described work of assembling the adapter 30 to the cylindrical blade 10. That is, as briefly described, by rotating the tightening ring 33 in the reverse direction and releasing the pressure on the second plate by the tightening ring 33, the grooves formed in the peripheral portions of the first plate 31 and the second plate 32 are formed. Wider and deeper, the split ring 34 contracts and is accommodated. Then, the pressing of the split ring 34 on the inner wall of the tubular blade 10 is released, and the split ring 34 is placed in the same plane as the outer peripheral surfaces of the first plate 31 and the second plate 32. Therefore, the adapter 30 is easily separated from the tubular blade 10.

As described above in detail based on the embodiment,
The boring cutter BC1 according to the present embodiment has a configuration in which the first plate 31 and the second plate 32 are brought close to each other by rotating the tightening ring 33.

Therefore, unlike the conventional boring cutter in which both the plates 31 and 32 are brought close to each other by the rotational movement of the first plate 31, the plates 31 and 32 can be brought close to and separated from each other without using a tool. That is, the cylindrical blade 10 and the adapter 30 can be easily separated from each other, and the work efficiency in the drilling work that requires frequent attachment / detachment of the cylindrical blade 10 and the adapter 30 is significantly improved. You can

In addition, when attaching and detaching the cylindrical blade 10 and the adapter 30, it is not necessary to rotationally move the first plate 31 that is in direct contact with the shavings.
Mounting portion 31a and first plate mounting portion 22 of shank 20
It is possible to prevent the screwed portion from being damaged by the intrusion of shavings into the screwed portion with. Further, the removal work is not hindered by the intrusion of shavings into the screwed portion.

Further, the adapter mounting portion 1 of the tubular blade 10
3 is formed with an engaging groove portion 13b on the inner wall, and the split ring 34
Since the engaging protrusion 34a is formed on the outer peripheral surface of the cylindrical blade body 10, the adapter 30 assembled to the cylindrical blade body 10 is
Can be reliably prevented from moving in the longitudinal direction. Similarly, the adapter mounting portion has a locking pin receiving portion 1
3a is formed, and the third locking hole 32f of the second plate 32 is formed.
Since the locking pin 38 that is fitted in is locked, it is possible to prevent the adapter 30 from being displaced in the rotational direction with respect to the tubular blade 10.

Further, the first plate 31 and the second plate 3
Since the corrugated washer 35 is interposed between the two, the first plate 31 and the second plate 32 can be easily separated. Furthermore, since the corrugated ring 34 always applies a reaction force to the tightening ring 33 that tightens the first plate 31 and the second plate 32, the thread of the shank 20 and the screw of the tightening ring 33 are It is possible to prevent the tightening ring 33 from loosening due to the vibration accompanying the punching work while the groove and the groove are maintained in a crimped state.

The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and various modifications and improvements can be made without departing from the spirit of the present invention. It is easily guessed.

For example, in this embodiment, the cylindrical blade 10 has four
Although it is provided with one blade, it may be provided with one blade or a plurality of blades as long as it has an optimum number of blades and a shape blade for punching the object to be punched. Although the center drill 40 is used to determine the drilling position, a center pin may be used when the diameter of the cylindrical blade is small. Since the center pin expands and contracts by an elastic member such as a spring, it is not necessary to wait for the center drill 40 to drill to a predetermined position as in the case of using the center drill 40.

Further, the tightening ring 3 which has been reduced in weight
As 3, a groove 33b is formed on the outer peripheral portion, but as shown in FIG. 9, a member having a U-shaped cross section is cut between the third mounted portion 52 and the outer peripheral surface 53. It is also possible to use a lightened tightening ring 50 having an annular portion 51 in which the lightening portion 54 is formed. In such a case, since the outer peripheral surface is formed in a planar shape, there is an advantage that the rotational operability of the tightening ring is improved.

Although not mentioned in the claims, the technical idea grasped from the above embodiments will be described below together with the effects thereof. The boring cutter according to any one of claims 1 to 4, wherein a center drill or a center pin is attached to a tip portion of the shank. With this configuration, the drilling position can be easily determined, and since it is supported by the center pin or the center drill, the drilling work can be performed easily and accurately.

[0069]

As described above, the boring cutter according to the present invention has a structure in which the adapter is attached to the cylindrical blade body by rotating the tightening ring, so that the shank (adapter) and the blade body can be attached and detached. It can be done easily.

When the structure according to claim 2 is provided, it is possible to smoothly expand the diameter of the diameter expanding ring, and further to the degree of proximity of the first plate and the second plate. When the configuration described in Item 3 is provided, the blade body and the shank (adapter) can be reliably connected, and in particular, the displacement of the tubular blade body in the length direction can be prevented.

Furthermore, in the case where the structure described in claim 4 is provided, the torque required to start the rotation of the boring cutter can be reduced, and the moment of inertia generated in the tightening ring due to the rotation can be reduced. can do.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of the boring cutter according to the present embodiment with a part broken away to explain the overall structure thereof.

FIG. 2 is an explanatory view showing a part of the boring cutter in cross section when viewed from the side.

FIG. 3 is an explanatory view showing a cross section of a part of a tubular blade body that constitutes a boring cutter when viewed from the side.

FIG. 4 is an explanatory view showing the adapter mounting portion of the tubular blade body shown in FIG.

FIG. 5 is a front view of a cylindrical blade body that constitutes a boring cutter.

FIG. 6 is a side view of a shank forming a boring cutter, a part of which is shown in cross section.

FIG. 7 shows an adapter assembled to a shank,
It is explanatory drawing which shows the state which is not tightened by the tightening ring.

FIG. 8 is an adapter assembled to a shank,
It is explanatory drawing which shows the state clamped by the clamp ring.

FIG. 9 is a side view of a clamping ring with a partial cross section to show a clamping ring having another shape.

FIG. 10 is an overall perspective view showing a part of the boring cutter according to a conventional example in order to explain the overall structure thereof.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Cylindrical blade, 13 ... Adapter mounting part, 20 ... Shank, 22 ... 1st plate mounting part, 23 ... 2nd plate mounting part, 24 ... Tightening ring mounting part, 30 ... Adapter,
31 ... First plate, 32 ... Second plate, 33 ... Tightening ring, 34 ... Split ring, 35 ... Corrugated washer,
100 ... Adapter, 101 ... Moving plate, 102 ... Fixed plate, 103 ... Split ring, 110 ... Shank,
120 ... Cylindrical blade

Claims (4)

[Claims] 1. A cylindrical blade body having a bottomless cylindrical shape and a blade portion formed on the periphery of one opening, and a driving force attached to the driving device and transmitting the driving force to the cylindrical blade body. A boring cutter including a shank and an adapter that connects the tubular blade body and the shank, wherein the adapter is attached to the shank via a first attachment portion formed in the center thereof. A disc-shaped first plate, a second plate attached to the shank through an attachment hole formed in the center thereof, and a second attached portion formed in the center of the shank to the shank. A tightening ring that is attached so as to be capable of advancing and retreating and that brings the second plate closer to the first plate; and a first ring that is arranged along the peripheral edges of the first plate and the second plate. The above A diameter-expanding ring that expands in diameter as it approaches the two plates, and the shank has a first attachment portion near the tip thereof, to which the first attachment portion is detachably attached. A boring cutter, characterized in that a second attaching portion to which the second attached portion is attached so as to be capable of advancing and retracting is formed in the vicinity of a central portion thereof. 2. The boring cutter according to claim 1, wherein at least one peripheral edge of the peripheral edges of the first plate and the second plate is tapered. A bowling cutter. 3. The boring cutter according to claim 1 or 2, wherein an engagement portion with which the expansion ring is engaged is formed on an inner wall surface of the tubular blade body. A bowling cutter. 4. The boring cutter according to any one of claims 1 to 3, wherein a concave peripheral portion is formed at a peripheral edge of the second attached portion of the tightening ring. A bowling cutter characterized by.