JP2000107919A - Hole saw and drilling tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a hole saw to cope with workpieces such as wall parts of a building in which metallic materials are mixed, without replacing the hole saw, and thereby to apply drilling operation to the workpieces without causing a drop in the working efficiency. SOLUTION: In a hole saw 4 made up of a cylindrical body 41 and a cutting part 44 formed on one end edge of the body 41, plural cutting tools 45 formed circumferentially at about equal intervals and relief grooves 46 for discharging chips formed between the cutting tools 45 are provided on the cutting part 44. The relief grooves 46 are each composed of short relief grooves 46a the depth of each of which is shallow, and a long relief groove 46b the depth of which is deep, and the cutting edges 45 are made of cemented carbide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hole saw for forming a circular hole in a workpiece and a hole drilling tool using the hole saw.

[0002]

2. Description of the Related Art Conventionally, a drilling tool having a hole saw as disclosed in Japanese Patent Application Laid-Open No. 9-207014 is known. As shown in FIG. 9, the drilling tool 100 includes a tool mounting portion 110, a center drill 120 and a hole saw 130 which are concentrically and removably mounted on the tool mounting portion 110. The tool mounting portion 110 has a prismatic drive connection portion 111 on the base end side (left side in FIG. 9) for connecting to an unillustrated electric motor having a drive motor therein, and has a distal end side. A rectangular insertion hole 112 in a cross-sectional view for inserting the base end of the center drill 120 and a male screw portion 113 for screwing the hole saw 130 are provided.

[0003] A square pillar 121 corresponding to the insertion hole 112 is formed on the base end side of the center drill 120, and a helical drill blade 122 is formed on the tip end side.

The hole saw 130 includes a cylindrical body 131, a base wall 132 provided so as to close an opening at the base end of the body 131, and a cutting portion 133 formed at the front end of the body 131. Consists of Base wall 13
A screw hole 132a corresponding to the male screw portion 113 is screwed into the center portion of the screw hole 132, and the screw hole 132a is screwed into the male screw portion 113 to be fastened.
Is mounted on the tool mounting section 110.

[0005] The cutting portion 133 is formed with a plurality of notched grooves 134 in the circumferential direction formed by cutting the front edge of the body 131. A cutting blade 134a for cutting a workpiece is formed at a corner of the entrance portion of the notch groove 134.

The center drill 120 and the hole saw 130 are mounted on the tool mounting portion 110 by inserting the prism portion 121 into the insertion hole 112 and screwing and screwing the screw hole 132a into the male screw portion 113. Become. The tool mounting portion 110 on which the center drill 120 and the hole saw 130 are mounted is connected to an electric motor (not shown), and the center of the drill bit 122 of the center drill 120 is pressed against a workpiece such as a wall surface of a building to position the workpiece.
By driving the electric motor, the drill blade 122 is immersed in the workpiece.

After the cutting portion 133 of the hole saw 130 reaches the surface of the workpiece, the cutting blade 134a cuts the workpiece by rotation about the axis of the hole saw 130. It is cut along the rotation trajectory and cut out in a circular shape. The cutting chips formed by cutting with the cutting blade 134a are discharged to the outside through the notch 134.

[0008]

By the way, in the conventional drilling tool 100 as described above, when the workpiece is a wall made of only a wooden or mortar of a building, the wall portion is not formed. However, when a metal material such as a wire mesh or an iron plate is installed on the wall, the cutting portion 133 is originally designed for metal cutting. Therefore, there was a problem that the metal material could not be cut, and eventually a hole could not be formed in the wall.

Therefore, as a means for cutting the metal material, it is conceivable to increase the number of cutting blades 134a, that is, to increase the number of notch grooves 134. However, in order to be able to discharge chips efficiently, the notch grooves 134 are used.
Must be deeper than the wall thickness. When the number of grooves is increased, the solid portion between the cutout grooves 134 of the hole saw 130 is significantly reduced, and the overall strength and rigidity are reduced.
Therefore, conventionally, a single hole saw 130 cannot perform a boring process on a workpiece in which a non-metal material and a metal material are mixed.

Therefore, a hole saw 130 dedicated to metal materials is used.
And two types of hole saws 130 dedicated to non-metallic materials are prepared in advance and replaced and used each time. However, during the drilling work on the wall, the tool mounting part 110 is used.
, The hole saw must be replaced, which is very troublesome and greatly reduces the work efficiency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and does not require a hole saw to be replaced with a workpiece such as a wall of a building in which metal materials are mixed. It is an object of the present invention to provide a hole saw and a drilling tool capable of performing a drilling operation on a workpiece without reducing the working efficiency.

[0012]

According to a first aspect of the present invention, there is provided a hole saw comprising a cylindrical body and a cutting portion formed at one edge of the body. A plurality of cutting blades formed at substantially equal intervals in the circumferential direction, and a relief groove for releasing chips formed between the cutting blades are provided, and the relief groove is a short escape groove having a shallow groove depth, The cutting blade comprises a long relief groove having a large depth, and the cutting blade is formed of a cemented carbide.

According to this hole saw, by providing both long and short relief grooves, it is possible to increase the number of grooves, that is, the number of blades, thereby making it possible to cut a metal material.

In addition, even when a workpiece having a large thickness is drilled, the cuttings (saw chips) are guided to the long escape groove and discharged to the outside, while the cuttings encounter the workpiece. The metal material is cut by the cutting blade, and the generated cutting waste is stored in the short escape groove, so the cutting blade is clogged with sawdust and cutting waste and the drilling operation is performed smoothly. The inconvenience of disappearance is reliably prevented. Therefore, even a thick wall in which metal materials are mixed can be bored with a single hole saw without replacing the hole saw one by one.

In other words, when all the grooves of the hole saw are shallow, it is possible to cut a plate-shaped metal material having a small thickness, whereas a non-metal material having a large thickness is cut by a cutting blade. There is an inconvenience that cutting is not performed smoothly due to clogging, but such inconvenience can be avoided by interposing a short escape groove between the long escape grooves.

The short relief groove of the hole saw has a groove depth substantially equal to the thickness of the metal material and is significantly shallower than the long relief groove. If it is deep, the solid portion between the grooves becomes a thin plate, and the thin plate-shaped portion is deformed by the reaction force received by the cutting blade from the metal material when cutting the metal material, and the cutting operation is smoothly performed. The inconvenience of not being able to do it occurs,
Such inconvenience can be avoided by interposing a short escape groove between the long escape grooves.

Since the capacity of the short escape groove is increased by setting the depth of the short escape groove deeper than the thickness dimension of the metal plate material to be drilled, the dimension setting metal material is cut with a cutting blade. The amount of cutting chips (cutting chips) formed by cutting increases in the short escape groove, thereby avoiding the inconvenience that the metal material cannot be cut due to clogging of the cutting blade and the long escape. By setting the groove depth of the groove deeper than the thickness of the nonmetallic material, the depth of the long escape groove is exposed to the outside even when the workpiece is penetrated by the hole saw, and the cutting blade The cut non-metallic sawdust is guided to the long escape groove and is smoothly discharged to the outside, so that a cutting defect caused by clogging by the sawdust can be reliably prevented.

The hole saw according to a second aspect of the present invention is the hole saw according to the first aspect, wherein the same number of short escape grooves are arranged between the long escape grooves.

According to this hole saw, the arrangement balance of the relief grooves is improved, which is advantageous in smoothly performing the drilling operation of the workpiece.

Further, since a plurality of short escape grooves are sandwiched between adjacent long escape grooves, the solid portion of the cut portion of the hole saw corresponding to the short escape groove has a large width dimension, In this portion, the cutting portion is hardly deformed even when a large force is applied in the circumferential direction, the resistance to the reaction force from the metal material during cutting is improved, and the deformation of the cutting portion is reliably prevented.

Further, even when the workpiece is penetrated by the hole saw, the depth of the long escape groove is exposed to the outside, so that the sawdust of the nonmetallic material cut by the cutting blade is long. It is guided to the escape groove and is smoothly discharged to the outside, so that cutting defects caused by clogging by sawdust are reliably prevented.

A hole saw according to a third aspect of the present invention is the hole saw according to the first or second aspect, wherein the cutting blade is made of a cemented carbide.

According to this hole saw, the metal material is cut well.

According to a fourth aspect of the present invention, there is provided a hole saw comprising a cylindrical body and a cutting portion formed at one edge of the body. A relief groove is provided, and a cutting blade is provided at each corner of each relief groove facing each other, and these cutting blades are set such that the amount of protrusion of the upstream one in the rotational direction is smaller than the amount of protrusion of the downstream one. It is characterized by having.

According to this hole saw, a cutting blade is provided at each of the corners of the relief groove facing each other, and two cutting blades are attached to each relief groove, so that only one relief groove is provided. Since the number of the cutting blades is doubled as compared with the case where the cutting blades are provided, cutting of the metal material is easily performed. Further, since the cutting blades opposed to each other by the relief groove are mounted stepwise, the metal material is cut by the cutting blade with a small protrusion amount and then sequentially and without difficulty by the cutting blade with a large protrusion amount.

According to a fifth aspect of the present invention, in the hole saw according to the fourth aspect, the relief groove is set such that a groove dimension on an inlet side is smaller than a groove dimension on a groove rear side. Is what you do.

According to this hole saw, since the groove size on the entrance side of the relief groove is reduced, when the metal material in the workpiece is, for example, a metal rod such as a reinforcing bar provided inside a mortar layer, When the drilling operation is performed, the inconvenience that the metal rod is fitted into the escape groove and thereby the rotation of the hole saw is hindered is avoided.

According to a sixth aspect of the present invention, there is provided a drilling tool according to any one of the first to fourth aspects, further comprising a tool mounting portion, the tool being mounted on the tool mounting portion, and a cutting blade provided at a tip. And a center drill detachably mounted on the tool mounting portion at a position concentric with the body.

According to this drilling tool, the hole saw of the drilling tool has the same operation as the hole saw of the first to third aspects, and the drilling position can be determined by the center drill. In addition, the drilling operation by the hole saw is stabilized.

[0030]

FIG. 1 is an exploded perspective view, partially cut away, showing an embodiment of a drilling tool according to the present invention.
FIG. FIG. 3 is a cross-sectional view of FIG.
FIG. 4 is a sectional view taken along line A, and FIG. 4 is a view taken along line B in FIG. First, as shown in FIGS. 1 to 3, a drilling tool 1 includes a tool mounting portion 2 that is removably mounted on a drive unit (not shown) in which an electric motor is mounted, and a tool mounting portion 2 that is removably mounted on the tool mounting portion 2. Has a basic configuration consisting of a center drill 3 mounted on the hole saw 4 and the hole saw 4. Then, the drilling tool 1 is used for cutting a workpiece such as a wall or a floor of a building sequentially from the surface into a circular shape by the rotation of the hole saw 4 due to the rotation, thereby making a circular hole in the workpiece. What is used. Specifically, after positioning the drilling tool 1 by projecting the tip of the center drill 3 to the center of the drilling of the workpiece, the driving machine drives the center drill 3 and the hole saw 4 via the tool mounting unit 2. Are integrally rotated about the axis of the center drill 3, and the workpiece is sequentially cut from the surface by the hole saw 4, thereby forming a circular hole in the workpiece.

The tool mounting portion 2 is concentric with a mounting portion main body 21 formed of a cylindrical body having a step in the longitudinal direction and a base end side (right side in FIGS. 1 to 3) of the mounting portion main body 21. And a drive connection member 26 screwed with the same. The mounting portion main body 21 has a male screw portion 22 having a smaller diameter than the central portion where the male screw is screwed on the peripheral surface on the distal end side (left side in FIGS. 1 to 3), and has a full circumference at the central portion. A flange portion 23 is provided in the mounting portion main body 21 on the base end side of the flange portion 23, and a screw hole 24 in which a female screw for screwing the drive connecting member 26 is concentrically provided. Is provided. Also, the mounting portion main body 21 on the tip side from the flange portion 23
A mounting hole 25 for mounting the center drill 3 is formed concentrically from the end face.

The drive connecting member 26 includes a cylindrical connecting portion main body 27, a flange 28 having a diameter larger than that of the connecting portion main body 27 formed concentrically and integrally with the distal end of the connecting portion main body 27, A male screw portion 29 is provided on the peripheral surface of the portion 28, which is provided concentrically with the distal end surface thereof, and has a male screw corresponding to the screw hole 24. Then, the male screw portion 29 is screwed into the screw hole 24 and fastened, whereby the drive connecting member 2
6 is integrally connected to the mounting portion main body 21 to form the tool mounting portion 2. On the outer peripheral surface of the connecting portion main body 27, three uneven planes extending in the longitudinal direction at an equal pitch in the circumferential direction are formed. It is designed to be fitted internally.

The center drill 3 has a drill body 31 having a helical drill blade 31a formed at the distal end thereof, and a cylindrical column having a smaller diameter than the drill body 31 projecting concentrically from the base end side of the drill body 31. Mounting portion 32 and the mounting portion 3
2 is a rectangular axis 3 having a rectangular cross section and protruding concentrically from the base end face 2
It consists of three. Further, a peripheral groove 32a is formed on the peripheral surface of the mounting portion 32 so as to be concave over the entire periphery.

On the other hand, as shown in FIG. 3, the mounting hole 25 of the mounting portion main body 21 is provided with a square hole 25a corresponding to the square shaft 33 of the center drill 3 at the back, and a flange portion. A plurality of radially extending ball holes 21a drilled at equal pitches in the circumferential direction are formed in a portion corresponding to the circumferential groove 32a of the center drill 3 in the mounting portion main body 21 at a portion forward of the center drill 23. A steel ball 21b is inserted into the hole 21a.

The inner diameter of the ball hole 21a is set to be smaller than the diameter of the steel ball 21b on the inner peripheral surface side of the mounting portion main body 21, whereby the steel ball 21b inserted into the ball hole 21a is partially formed. Is the mounting hole 25
When it is immersed inside, it does not come out toward the mounting hole 25. A peripheral groove 21c is formed in the outer peripheral surface of the mounting portion main body 21 so as to connect the ball holes 21a. A C-ring 21 which can be elastically deformed in the circumferential groove 21c.
The steel ball 21b inserted into the ball hole 21a is urged toward the center of the mounting hole 25 by the elastic force of the C ring 21d.

Accordingly, by inserting the center drill 3 into the mounting hole 25 and fitting the square shaft 33 into the square hole 25a, the center drill 3 is mounted on the tool mounting part 2 so as to be able to rotate around the axis. Each steel ball 21b fits into the peripheral groove 32a of the center drill 3, whereby the center drill 3 is in a state where it is prevented from coming off.

The drill body 31 of the center drill 3
, A disk 34 is concentrically fixed to the base end side thereof by welding stopper or the like. The disk 34 is used to discharge chips remaining in the hole saw 4 after the workpiece is punched by the hole saw 4, and the residual chips are removed by using the center drill 3 from the inside of the hole saw 4. By being pulled out, it is pressed by the disk 34 and discharged to the outside.

The present invention is not limited to the use of the steel ball 21b as a measure for preventing the center drill 3 from coming off. For example, a bolt may be screwed into the mounting part body 21 from the side. The center drill 3 may be pressed and locked at its tip to prevent it from falling off.

The hole saw 4 has a basic structure comprising a cylindrical body 41 made of iron and an annular wall 42 fitted on the base end side of the body 41 and fixed by welding or the like. A screw hole 43 in which a female screw is screwed into the male screw portion 22 is screwed into a center portion of the annular wall 42, and the screw hole 43 is screwed into the male screw portion 22 and fastened. The hole saw 4 is mounted on the tool mounting section 2.

The body 41 has a cutting portion 44 (a portion of the body 41 shown in FIGS. 1 and 2 on the tip side with respect to a dashed line) formed on the tip side. The cutting portion 44 includes a plurality of cutting blades integrally attached at substantially equal intervals in the circumferential direction at corners (not limited to the corners, but may be near the corners) of each relief groove 46. 45 and an escape groove 46 for allowing chips formed between the cutting blades 45 to escape. As the cutting blade 45, WC, Ti
WC-Co, WC-Ti is an alloy obtained by sintering carbide powder of a high melting point metal such as C or TaC using Co as a binder.
C-Co type or WC-TiC-Ta (Nb) C-
A so-called cemented carbide such as a Co-based alloy is used.

The cutting blade 45 is formed by forming such a cemented carbide into a substantially rectangular parallelepiped strip. As shown in FIG. 4, such a cutting blade 45 is fixed to the edge of the escape groove 46 on the clockwise side by brazing using silver. In the present embodiment, the outer diameter (diameter) of the body 41 is set to 120 mm.
At one end, relief grooves 46 of 16 grooves are formed at a constant pitch in the circumferential direction. One cutting blade 45 is also provided for each relief groove 46.
Six are employed. Further, as shown in FIG. 3, the protrusion amount d1 of the cutting blade 45 from the body edge 41a is set to 0.5 mm ± 0.1 mm as shown in FIG.

Then, in a state where the front edge of the body 41 is pressed against the surface of the workpiece, the hole saw 4 is rotated around the center drill 3 via the tool mounting portion 2 by driving of a driving machine (not shown) in FIG. By rotating in the counterclockwise direction, the surface of the workpiece is cut in a circular shape by the cutting blade 45, whereby a circular hole is formed in the workpiece.

The escape groove 46 is composed of a short escape groove 46a having a shallow groove depth and a long escape groove 46b having a deep groove depth. The groove width dimension d2 of each relief groove 46a, 46b is set to approximately 6 mm. In addition, the short escape groove 4
6a is formed in an arc shape, the groove depth d3 to the innermost portion thereof is set to approximately 4 mm, and the long escape groove 46b is formed in a straight shape, and the groove depth d4 is formed.
Is set to 40 mm to 50 mm.

The groove depth dimension d3 of the short escape groove 46a, which is approximately 4 mm, is a value that is set to be larger than the assumed thickness dimension of the metal material provided in the wall of the building as the workpiece. By doing so, the metal chips (from the metal material in the chips) are accommodated in the short escape groove 46a, and the disadvantage that the metal material cannot be cut due to clogging is avoided.

The length d40 of the long relief groove 46b of 40 mm to 50 mm is assumed to be a material (wood, mortar layer, etc.) other than the metal material constituting the wall of the building as the workpiece. The thickness is set to be slightly larger than the thickness dimension to be formed, so that saw chips such as a mortar layer cut by the cutting blade 45 (from the mortar layer in the chips) are inserted into the long escape groove 46b. Since it is guided and released to the outside, it is possible to reliably prevent the occurrence of cutting defects due to clogging with sawdust.

The present invention is not limited to the dimensional specifications of the hole saw 4 set as described above, but the size of the hole to be drilled, the material and thickness of the workpiece. Needless to say, it can be appropriately changed according to the conditions.

FIGS. 5 and 6 are explanatory views for explaining the operation of the present invention. FIG. 5A shows a state in which the drilling position is determined, and FIG. 6A shows a state in which the metal material is being drilled, and FIG. 6B shows a state in which the drilling operation is completed. In FIGS. 5 and 6,
A case is illustrated in which a piercing operation is performed on a wall portion 5 of a building in which a plate-shaped metal material 52 is provided inside a mortar layer 51 as a workpiece.

First, in the state shown in FIG. 5A, the tip of the center drill 3 is pushed up to the center of the drilling position on the surface of the wall 5 so that the drilling tool 1 is positioned. It has become. By driving the driving machine 6 in this state, first, the mortar layer 51 of the wall portion 5 is pierced by the rotation of the center drill 3, and the mortar layer 51 co-rotates with the center drill 3 by moving the center drill 3 forward (moving to the left). The hole saw 4 moves forward, and the cutting blade 45 comes into contact with the surface of the mortar layer 51 while rotating. In this state, when the driving machine 6 is pressed forward (to the left in FIG. 5), the hole saw 4 advances while rotating about the axis, and the mortar layer 51 is cut into a circular shape. As shown in ()), circular holes 53 are sequentially formed.

When the cutting blade 45 of the hole saw 4 is in the mortar layer 51, the saw dust of the mortar layer 51 formed by cutting is guided by the long escape groove 46b and is located on the base end side of the hole saw 4 (see FIG. 5 (to the right of 5), and is discharged from the long escape groove 46b to the outside when it comes out of the circular hole 53.

By continuing to press the drive unit 6 against the wall 5, the cutting blade 45 reaches the metal material 52 as shown in FIG. By continuing the pressing in this state, the metal material 52 is cut by the cutting blade 45 revolving around the center drill 3. Since a sufficient number of cutting blades 45 are provided to cut the metal material 52, the metal material 52 is cut smoothly by the cutting blade 45. The formed cuttings are stored in the short escape groove 46a. Therefore, the cutting blade 45 is not clogged by the cutting chips, and there is no inconvenience such as poor cutting.

The short escape groove 46a has a groove depth set to be substantially the same as the thickness of the metal material 52, and
6b, the strength and rigidity of the cutting portion 44 are sufficient, so that the inconvenience that the cutting portion 44 of the body 41 is deformed when the metal material is cut by the cutting blade 45 is avoided. That is, if all grooves are deep,
The solid portion between the grooves becomes a thin plate, and the metal material 5
In the cutting of No. 2, there is a disadvantage that the thin plate-like portion is deformed by the reaction force received from the metal material 52 by the cutting blade 45 and the cutting operation cannot be performed smoothly. However, such a disadvantage occurs between the long escape grooves 46b. This can be avoided by interposing the short escape groove 46a.

When the drive unit 6 is further pressed toward the wall 5 from the state shown in FIG. 6A, the wall 5 is penetrated by the hole saw 4 as shown in FIG. Then, the hollow chips 7 remain in the hole saw 4. After the hole saw 4 is pulled out from the wall portion 5 and the center drill 3 is pulled out from the tool mounting portion 2, the hollow chips 7 are removed from the disk 34 on the base end side of the center drill 3.
And is discharged from the inside of the hole saw 4 to the outside.

As described in detail above, the drilling tool 1 of the present invention has the hole saw 4 provided with the short escape groove 46a and the long escape groove 46b, so that the wood, mortar layer, etc. When the hole saw 4 is rotated around the axis to perform the boring process on the wall 5 of a building or the like that is made of a non-metal material and partially includes a plate-shaped metal material, When cutting the large mortar layer 51, the sawdust is guided to the long escape groove 46b and discharged to the outside, while the metal material 52 in the workpiece encountered by the cutting portion 44 is cut by the cutting blade 45. At the same time, since the generated cutting chips are stored in the short escape groove 46a, the inconvenience that the cutting blade 45 is clogged with the saw chips and the cutting chips and the drilling operation is not smoothly performed is reliably prevented. You.

The short escape groove 46a of the hole saw 4
Since the groove depth is set to be substantially the same as the thickness dimension of the metal material 52 and is significantly shallower than the long escape groove 46b, the cutting portion 44 is sufficiently strong in strength, and The inconvenience that the cutting blade 45 is deformed by the reaction force received from the metal material 52 at the time of cutting the 52 can be avoided.

When all the grooves of the hole saw 4 are shallow, the plate-shaped metal material 52 can be cut. However, the mortar layer 51 having a large thickness dimension causes the cutting blade 45 to be clogged. As a result, there is a problem that the cutting is not performed smoothly.
This can be avoided by interposing the short escape groove 46a between them.

As described above, the hole saw 4 of the present invention and the drilling tool 1 using the hole saw 4 can be used even when the workpiece is a non-metal material mixed with a metal material.
On the other hand, it is possible to perform the drilling operation smoothly,
Therefore, it mainly consists of a non-metallic material such as wood or mortar material, and a wall or a floor of a building in which a metal material such as an iron plate or a reinforcing bar is installed according to a material that the cutting blade 45 hits. Since it is not necessary to replace the hole saw one by one, the work efficiency can be improved by that much, and it is particularly suitable for use in the construction industry.

7 and 8 are views showing another embodiment of the hole saw according to the present invention. FIG. 7 is a partially cutaway perspective view, and FIG. 8 is a sectional view taken along line CC of FIG. is there. As shown in these figures, in this embodiment, the body 41
The cutting portion 44 is not provided with a short escape groove 46a. Instead, the long escape groove 46b is provided with a cutting blade 45 opposed to a corner at the tip end of each groove.

These cutting blades 45 are the counterclockwise rotating direction of the drilling tool 1 in FIG. 7, and the amount of protrusion of the upstream cutting blade 45a is such that the downstream cutting edge 45a faces the upstream cutting blade 45a. It is set smaller by the distance d5 than the protrusion amount of the blade 45b. Accordingly, since the metal material 52 is first cut by the upstream cutting blade 45a having a small protrusion amount and then by the downstream cutting blade 45b having a large protrusion amount, the cutting operation is smoothly and smoothly performed, and It is possible to make a hole smoothly.

The upstream cutting blade 45a is fixed to the body 41 by being brazed at the corner of the long escape groove 46b while being fitted into the cut formed by cutting into the body 41. Thereby, the fixed state of the upstream cutting blade 45a is stabilized, so that the upstream cutting blade 45a does not easily fall off even if a force is applied to the upstream cutting blade 45a in the direction of the long escape groove 46b during cutting. I have to.

The width of the groove on the entrance side of the long escape groove 46b is set to be smaller than the diameter of the reinforcing bar provided inside the wall 5 of a normal building. 46b so as not to inconvenience such that the drilling operation is interrupted.

Further, the long escape groove 46b is provided with the cutting blade 45.
The width of the groove on the far side is widened. By doing so, the capacity for storing cutting chips and saw chips in the long escape groove 46b is increased, and cutting defects due to clogging of the cutting blade 45 are less likely to occur.

The present invention is not limited to the above embodiment, but includes the following contents.

(1) In the embodiment shown in FIGS. 1 to 4, the outer diameter of the body 41 is set to 120 mm, and the body 41 has four long relief grooves 46b recessed. Although three short escape grooves 46a are recessed between the long escape grooves 46b, the present invention does not require the adoption of such dimensions and numbers, and various types are used depending on the condition of the workpiece. The dimensions and the number of grooves can be set as appropriate. This is the same in the other embodiments shown in FIGS. 7 and 8.

(2) In the above other embodiment, the short escape groove 46 is provided at the edge of the cutting portion 44 between the long escape grooves 46b.
It is also possible to provide only the cutting blade 45 without recessing a.
By doing so, the number of cutting blades 45 per one body 41 is increased, and the drilling tool 1 is more suitable for cutting a metal material.

[0065]

According to the hole saw according to the first aspect of the present invention, a plurality of cutting blades formed at substantially equal intervals in the circumferential direction on the cutting portion of the cylindrical body, and the cutting formed between the cutting blades. An escape groove is provided to allow the debris to escape, and the escape groove is made up of a short escape groove with a shallow groove depth and a long escape groove with a deep groove depth. The number of grooves, that is, the number of blades, can be increased, so that the hole saw can perform cutting of a metal material, and can also perform a drilling operation of a nonmetal material due to the presence of a long escape groove. As a result, it is not necessary to replace the hole saw with a dedicated one due to a difference in the material of the workpiece as in the related art, and the work efficiency can be improved accordingly.

According to the hole saw according to the second aspect of the present invention, since the long escape grooves are formed for every predetermined number of the short escape grooves, a plurality of short escape grooves are sandwiched between the adjacent long escape grooves. As a result, the width of the solid portion of the cut portion of the hole saw corresponding to the short escape groove can be increased. Therefore, in this portion, the cutting portion is hardly deformed even when a large force is applied in the circumferential direction, thereby making it possible to withstand the reaction force from the metal material at the time of cutting, and reliably deforming the cutting portion. Can be prevented.

According to the hole saw according to the third aspect of the present invention, since the cutting blade is made of a cemented carbide, the metal material can be cut well.

According to the hole saw according to the fourth aspect of the present invention, since the cutting blades are provided at the corners of the relief grooves facing each other at different levels, only one cutting blade is provided for each relief groove. As compared with the case, the number of cutting blades is doubled, whereby the cutting of the metal material can be easily performed.
In addition, since the cutting blades are mounted stepwise, it is possible to cut metal material with a cutting blade with a small protrusion amount and then with a cutting blade with a large protrusion amount. It is effective in doing.

According to the hole saw of the fifth aspect of the present invention, since the groove size on the inlet side of the relief groove is set smaller than the groove size on the deep side, the metal material in the workpiece is, for example, embedded in the mortar layer. If the rod is a metal bar like
It is possible to avoid the inconvenience that the metal bar fits into the escape groove during the drilling operation by the hole saw, thereby hindering the rotation of the hole saw.

According to the drilling tool of claim 6 of the present invention, a tool mounting portion, and a tool mounted on the tool mounting portion, and
Since a hole drilling tool is formed by the hole saw according to any one of claims 1 to 3 having a cutting blade at a tip thereof, and a center drill detachably mounted at a tool mounting portion at a position concentric with the body, Claim 1 is a hole saw drilling tool.
In addition to having the same effect as the hole saw described in any one of (1) to (3), the drilling position can be determined by the center drill, and the drilling operation by the hole saw can be performed in a stable state.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view, partially cut away, showing an embodiment of a drilling tool according to the present invention.

FIG. 2 is an assembled perspective view of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a diagram viewed from the line B in FIG. 2;

FIG. 5 is an explanatory diagram for explaining an operation of the present invention;
(A) shows the state where the drilling position is positioned, and (B) shows the state where the mortar layer is being drilled.

FIG. 6 is an explanatory diagram for explaining an operation of the present invention;
(A) shows a state where the metal material is being drilled, and (B) shows a state where the drilling operation is completed.

FIG. 7 is a partially cutaway perspective view showing another embodiment of the hole saw according to the present invention.

FIG. 8 is a sectional view taken along line CC of FIG. 7;

FIG. 9 is an explanatory view in a cross-sectional view illustrating a conventional hole saw and a drilling tool.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drilling tool 2 Tool mounting part 21 Mounting part main body 21a Ball hole 21b Steel ball 21c Peripheral groove 21d C ring 22 Male screw part 23 Flange part 24 Screw hole 25 Mounting hole 25a Square hole 26 Drive connection member 27 Connection part main body 28 Flange 29 Male thread part 3 Center drill 31 Drill body 31a Drill blade 32 Mounting part 32a Peripheral groove 33 Square axis 34 Disk 4 Hole saw 41 Body 42 Annular wall 43 Screw hole 44 Cutting part 45 Cutting blade 45a Upstream cutting blade 45b Downstream cutting blade 46 Escape groove 46a Short escape groove 46b Long escape groove 5 Wall 51 Mortar layer 52 Metal material 53 Circular hole 6 Drive unit 7

Claims (6)

[Claims] 1. A hole saw comprising a cylindrical body and a cut portion formed at one end of the body, wherein the cut portion has a plurality of long relief grooves having a large groove depth.
A relief groove consisting of a short relief groove with a shallow depth formed between adjacent long relief grooves is provided, and a cutting blade is provided at or near the end of each relief groove. And a hole saw. 2. The hole saw according to claim 1, wherein the same number of short escape grooves are arranged between the long escape grooves. 3. The hole saw according to claim 1, wherein the cutting blade is made of a cemented carbide. 4. In a hole saw comprising a cylindrical body and a cutting portion formed at one end of the body, the cutting portion is provided with a plurality of relief grooves arranged in a circumferential direction, and each relief groove is provided. A cutting blade is provided at each of the corners opposed to each other, and in these cutting blades, the protruding amount of the one on the upstream side in the rotation direction is set smaller than the protruding amount of the one on the downstream side. 5. The hole saw according to claim 4, wherein the relief groove has a groove dimension on the inlet side smaller than a groove dimension on the inner side of the groove. 6. A hole saw according to claim 1, further comprising a tool mounting portion, a cutting blade mounted on the tool mounting portion, and having a cutting blade at a tip thereof, and the tool mounting portion being concentric with the body. A center drill which is detachably mounted at a position.