JP2001198716A - Drilling tool and manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily attach/detach an edged tool to/from a tool main body, to increase reliability in the mounting state and to simplify the manufacturing. SOLUTION: This invention relates to a drilling tool in which a cylindrical mounting part 24 of an edged tool 20 is attached/detached to/from a tool main body 11 in an external fitting state and manufacturing method therefor. The cylindrical mounting part 24 is provided with a through hole 24a. A first mounting hole 24b is worked on a cylindrical mounting part inner peripheral surface on the axial center extension line through the through hole 24a and a fixed locking spherical body 26 is fixed to the mounting hole 24b. At a separate portion, a second mounting hole 24b is worked, a movable locking spherical body 26' is put into the mounting hole 24b and the inside is energized. In the tool main body 11, a locking groove 15 in which an axial first groove that the fixed locking spherical body 26 is invadable and a peripheral direction second groove are continuous and a whirl-stop recessed part 17 engaged to the movable locking spherical body 26' at a point of time when the fixed locking member 26 invades up to the second groove are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling tool for drilling holes in walls, ceilings, metal plates, and other workpieces, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a drilling tool as described above has a cutting tool having a plurality of cutting blades at an end of a substantially cylindrical body, and the cutting tool is mounted on a tool body. It is generally known that the main body is connected to a drive source such as a rotary drive so that the entire tool is integrally driven to rotate. Furthermore, in recent years, a plurality of types of blades having different processing diameters can be mounted on a single tool body, or a blade provided with the cutting blades at both ends in the axial direction of the blade for extending the life of the blade or the like is used. In order to be able to do so, a device to make the blade detachable from the tool body is being studied.

FIGS. 8A and 8B show examples of the structure. This tool has a tool body 80 connected to a drive source (not shown). A center drill 84 for center positioning is removably mounted on a tip portion 82 of the tool body 80.
The cutting tool 90 is detachably mounted on the outside of the.

The cutting tool 90 has a cylindrical body 91, and a plurality of cutting blades 92 are fixed to a tip portion thereof in a state of being arranged in the circumferential direction.
A cylindrical mounting portion 94 that is fitted to the front end portion 82 of the O. The cylindrical mounting portion 94 is provided with two screw holes 94a radially penetrating the cylindrical mounting portion 94 at intervals of 180 °, so that a set screw 96 can be inserted into each screw hole 94a while being screwed therein. . On the other hand, the tool body tip portion 82
On the outer peripheral surface of the tool body, two portions are cut out in a planar shape to form detent recesses 82a. The ends of the set screws 96 are fitted into the detent recesses 82a, respectively, so that the tool body is formed. A blade 90 is fixed to 80 and both are driven to rotate integrally.

[0005] The procedure for using this drilling tool is as follows.

A set screw 96 is screwed into each screw hole 94 a of the blade 90 in advance. At this time, each set screw 96 is positioned to the outside in the radial direction to some extent so that its end does not protrude inward from the inner peripheral surface of the cylindrical mounting portion 94.

A tool 90 is provided outside the tool body tip 82.
The cylindrical mounting portion 94 is fitted. And the tip 82
After adjusting the relative angle between the tool body 80 and the cutting tool 90 so that the positions of the detent recesses 82a and the set screws 96 match, the set screws 96 are turned in the tightening direction to be displaced inward, The ends are fitted into the respective detent recesses 82a (the attachment of the blade 90 to the tool body 80 is completed).

[0008] The tool main body 80 is connected to a rotary drive (not shown), and the entire drilling tool is rotationally driven. In this state, first, the center drill 84 is pressed against the construction surface to perform centering (centering positioning) of the processing hole, and then the periphery of the hole is cut by the cutting blade 92 of the cutting tool 90, so that the hole is substantially the same as the cutting tool 90. A hole with a diameter is made.

[0009]

In the above-mentioned drilling tool,
After the cylindrical mounting portion 94 of the cutting tool 90 is externally fitted to the tool main body distal end portion 82, it is necessary to perform a circumferential positioning operation to match the circumferential position of the set screw 96 with the circumferential position of the detent recess 82a. However, in such an externally fitted state, the rotation-stopping concave portion 82a is hidden inside the tubular mounting portion 94 and cannot be seen from the outside, so that the positioning operation is not easy. Further, even after positioning, it is necessary to rotate each set screw 96 individually, which is very troublesome.

[0010] Further, since all the relative rotation of the cutting tool 90 with respect to the tool body 80 is controlled by the engagement between the set screw 96 and the tool body 80, both set screws 96 become loose due to vibration during use or the like. When detached from the retaining concave portion 82a, the regulation of the relative rotation is removed, and the torque transmission from the tool body 80 to the blade 90 becomes impossible, so that the construction must be interrupted.

Further, when manufacturing this tool, a plurality of screw holes 94a must be provided in the cylindrical mounting portion 94, and the manufacture thereof requires time and effort.

The present invention has been made in view of such circumstances, and has a simple operation of attaching and detaching a blade to and from a tool body, and has high mounting reliability.
Another object of the present invention is to provide a drilling tool that is easy to manufacture and a method for easily manufacturing the drilling tool.

[0013]

As a means for solving the above-mentioned problems, the present invention comprises a tool body connected to a drive source and a cylindrical mounting portion which can be fitted to the outside of the tool body. A cutting tool fixed to the tool main body so as to rotate integrally with the tool main body in the fitted state, wherein the cylindrical mounting portion radially penetrates the cylindrical mounting portion. A through-hole is provided, and a first mounting hole is provided at a position on the inner peripheral surface of the cylindrical mounting portion on an extension of the axial center of the through-hole, and a first mounting hole is provided in the first mounting hole. The fixed locking member is fixed in a state protruding inward from the peripheral surface, and a second mounting hole is provided at a position different from the mounting hole in the circumferential direction on the inner peripheral surface of the cylindrical mounting portion. (2) movable in the radial direction of the cylindrical mounting portion in the mounting hole A dynamic locking member, and biasing means for biasing the movable locking member radially inward of the cylindrical mounting portion to project the movable locking member inward from the inner peripheral surface of the cylindrical mounting portion. Is attached to the outer peripheral surface of the tool main body, where the cylindrical mounting portion is fitted. The first locking engaging member can penetrate from the front end side of the tool main body to the rear side of the tool main body along the axial direction. A locking groove in which a groove and a second groove into which the fixed locking member can penetrate in the circumferential direction of the tool body from the end of the first groove; And a detent recess that engages with the movable locking member at a position where the tool enters and restricts relative rotation between the tool body and the blade.

According to this configuration, the blade can be easily attached to and detached from the tool body in the following manner. That is,
The cylindrical mounting portion is fitted to the outer peripheral surface of the tool main body while allowing the fixed locking member projecting from the inner peripheral surface of the cylindrical mounting portion of the blade to enter the first groove of the locking groove on the tool main body side, and The tool and the tool body are relatively rotated in the direction in which the fixed locking member enters the second groove from the end of the first groove, and the movable locking member is inserted into the detent recess provided in the tool body. What is necessary is just to make it engage. Until this engagement,
Since the movable locking member pressed against the outer peripheral surface of the tool body is immersed in the second mounting hole against the urging force of the urging means, regardless of the presence of the movable locking member, the engagement between the blade and the tool body is possible. The joint operation and the relative rotation operation are performed smoothly. Then, the relative rotation between the tool body and the blade is restricted by the engagement between the detent recess and the movable locking member, and the fixed locking member stops in the second groove of the locking groove by this restriction. As a result, the relative movement of the blade and the tool body in the axial direction is also restricted. In addition, an operation reverse to this operation, that is, an operation of relatively rotating the tool main body and the blade in a direction in which the fixed locking member goes backward in the second groove, and a case where the fixed locking member is axially moved from the first groove By performing the operation of extracting the blade from the tool main body so as to escape from the tool main body, the blade can be easily removed from the tool main body.

Therefore, according to this drilling tool, the blade can be attached and detached only by relatively moving the blade and the tool body in a predetermined direction, so that the blade and the tool body are separated from each other like a conventional tool. There is no need to perform a work of positioning in the circumferential direction in the fitted state, and a work of rotating the set screw is not required.

Further, the blade is fixed by engagement of the fixed locking member and the movable locking member on the cylindrical mounting portion side with the locking groove and the detent groove on the tool body side.
There is no possibility that the fixing is released due to the loosening of the set screw due to the vibration of the tool as in the related art.

In addition, this drilling tool is provided with a through-hole which penetrates the cylindrical mounting portion in the radial direction in the cylindrical mounting portion of the blade, and inserts another drilling tool into this through-hole to form the hole. The first tool is attached to the inner peripheral surface of the cylindrical mounting portion by an opening tool.
It can be easily manufactured by machining a mounting hole, inserting a fixed locking member from the outside of the cylindrical mounting portion into the first mounting hole through the through hole, and fixing. That is, according to this method, although the inner space of the cylindrical mounting portion is considerably narrow, the first mounting hole is formed and fixed to the first mounting hole through the through hole initially provided in the cylindrical mounting portion. The attachment of the locking member can be easily performed.

The specific shape of the fixed locking member and the movable locking member does not matter, but if at least one of them is a sphere, the contact resistance between the locking member and the tool body is reduced,
Operation becomes smoother. In addition, the tool body is less likely to be damaged.

Further, if the fixed locking member and the movable locking member are formed into spherical bodies having the same shape, mass productivity is improved.

Although the specific shape of the first mounting hole is not limited, the first mounting hole has a bottom, and the fixed locking member is inserted into the mounting hole until the first mounting hole comes into contact with the bottom. The amount of protrusion of the fixed locking member from the surface can be easily determined.

Here, any means for attaching the fixed locking member to the first mounting hole may be used, but an adhesive may be used. However, if the fixed locking member is press-fitted into the first mounting hole. ,
The fixed locking member can be easily attached.

The number of the first mounting holes and the fixed locking members is not particularly limited, but if these are provided at a plurality of different positions in the circumferential direction, the mounting reliability of the blade is further improved.

In the locking groove, the direction in which the second groove extends from the first groove is preferably set to a direction opposite to the direction in which the tool body is driven to rotate. With such a configuration, the cutting resistance applied to the blade during processing acts in a direction of displacing the fixed locking member of the blade to the inner side of the second groove (the side away from the first groove), so-called tightness. And the mounting reliability of the blade during machining is further improved.

On the other hand, with respect to the second mounting hole, a retaining portion for preventing the movable locking member from dropping from the second mounting hole to the inside of the cylindrical mounting portion is formed at an inner end thereof. Is preferred.

As a method of processing the second mounting hole and mounting the movable locking member on the second mounting hole, a through-hole which penetrates through the cylindrical mounting portion in the radial direction as the second mounting hole is prevented from coming off. Part so that the second part
After the movable locking member and the spring member as the urging means are loaded into the mounting hole, the outer opening of the second mounting hole is closed with a lid, and the spring member is sandwiched between the lid and the movable locking member. A method is preferable in which the movable locking member is compressed and deformed, and the movable locking member is biased radially inward of the cylindrical mounting portion by the elastic force of the spring member. According to this method, the processing of the second mounting hole and the mounting of the movable locking member and the urging means (spring member) to the second processing hole can be easily performed.

The present invention is applicable to various drilling tools in which a blade is removably mounted on a tool body. Specifically, the tool body is provided with a center drill at a tip thereof, and the cutting tool has a substantially cylindrical shape that covers the center drill in a coaxial state therewith, and a cutting blade is provided at the tip thereof. It is particularly suitable for tools having

For example, in the case where the blade has the cutting blade at both ends thereof and the cylindrical mounting portion at an intermediate portion,
By simplifying the work of attaching and detaching the tool body and blade,
It is possible to easily use the cutting at both ends of the blade easily. Moreover, the thickness of the cylindrical mounting portion is made larger than the thickness of the other portions, and the fixed locking member and the movable locking member are mounted on the cylindrical mounting portion. In addition, since it is only necessary to form the detent concave portion, the outer diameter of the tool body can be reduced, and as a result, the tool body can be inserted into the inside of the blade from any of both axial ends. Becomes possible.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the drawings.

The drilling tool shown here comprises a tool body 11 shown in FIGS. 1 to 3 and a cutting tool 2 shown in FIGS. 1, 4 and 5.
0.

A drive connecting portion 11a connected to a rotary drive (not shown) is formed at a rear portion of the tool body 11, and a center drill (drill bit) 12 is mounted at a front portion.

As shown in FIG. 2, the tool main body 11 has a drill mounting hole 11b extending along the center axis thereof and opening forward, and a drill mounting hole 11b extending from the outer peripheral surface of the tool main body.
A radial screw hole 11c is formed to connect to the inner part of the screw hole 11b. A set screw 14 having a fastening tool insertion recess 14a is screwed into the screw hole 11c.

On the other hand, a drill bit 12a is formed at the front part of the center drill 12, and a round shank part 12b is formed at the rear part thereof. Are formed. The shank portion 12b is provided in the drill mounting hole 11b of the tool body 11.
With the screw inserted in the screw hole 11c, the set screw 14 in the screw hole 11c is rotated by the tightening tool 13 to advance radially inward, and is engaged with the notch 12c. 12 is fixed.

A helical spring 18 for removing chips is mounted around the drill blade 12a of the center drill 12.

As shown in FIG. 3, the front end of the tool body 11 is formed as a small-diameter portion 11e having a smaller diameter than the rear portion.
A step 11d is formed at the boundary. The small diameter part 1
On the outer peripheral surface of 1e, two locking grooves 15 and one detent recess 17 are formed at positions aligned with each other in the circumferential direction.

Each locking groove 15 includes a first groove 15a extending rearward from the front end of the small-diameter portion 11e in the axial direction (in the illustrated example, a direction slightly inclined in the circumferential direction from the complete axial direction), and the first groove 15a. A second groove 15b extending in a circumferential direction from the end of the groove 15a (in the illustrated example, a direction inclined slightly backward from a complete circumferential direction).
Are formed continuously, and these locking grooves 1
5 are provided at positions spaced apart from each other by 60 ° in the circumferential direction. Then, the end of the second groove 15b of the two locking grooves 15 and the detent recess 17 are spaced from each other by 60 ° in the circumferential direction.
The formation positions of the detent recesses 17 are set so as to be arranged at intervals.

As shown in FIG. 4, the blade 20 has a substantially cylindrical shape which is symmetrical in the longitudinal direction. A plurality of cutting blades 21 arranged in the circumferential direction are provided at both front and rear ends, and a through hole 22 for chip discharge is provided at an appropriate position on the back side. The middle part of the blade 20 in the front-rear direction is a cylindrical mounting part 24 having a larger thickness (larger outer diameter and smaller inner diameter) than other parts, and the front end of the tool body 11 can be fitted inside the cylindrical mounting part 24 ( That is, the cylindrical mounting portion 24 can be fitted to the outside of the front end of the tool body 11). Further, by the contact between the rear end of the inner peripheral portion of the cylindrical mounting portion 24 and the step portion 11d of the tool main body 11, the positioning of the blade 20 with respect to the tool main body 11 in the axial direction is performed.

In FIG. 1 and the like, reference numeral 16 denotes a blade cover made of rubber or the like provided on the outer peripheral surface of the tool body 11 in the form of a flange, and the cutting blade 21 on the unused (rear end) side is used by an operator. This is to prevent exposure to the side.

As shown in FIG. 5, the cylindrical mounting portion 24
At the center position in the axial direction, two through-holes 24a penetrating therethrough in the radial direction are provided at intervals of 60 ° in the circumferential direction, and in the inner peripheral surface of the cylindrical mounting portion 24, Position on the axis extension line (that is, through hole 24
(a position opposed to a) is provided with a first mounting hole 24b having a hemispherical bottom, and a fixed locking sphere (fixed locking member) 28 is press-fitted into the first mounting hole 24b. Fixed. The head of the fixed locking sphere 26 protrudes slightly inward from the inner peripheral surface of the cylindrical protruding portion 24, and the protruding head is connected to the locking groove 1 in the tool body 11.
5, the first groove 15a and the second groove 15b can be penetrated.

Further, at a position between the two through-holes 24a, in other words, at a position arranged at intervals of 60 ° in the circumferential direction together with the two first mounting holes 24b, the cylindrical mounting portion 24 has a diameter thereof. A second mounting hole 24c penetrating in the direction is provided.

In the second mounting hole 24c, a movable locking sphere 26 'having the same shape as the fixed locking sphere 26 and a compression coil spring (spring member) 2 are formed from the outer peripheral surface side of the cylindrical mounting portion 24.
7 are loaded in this order, and the outside of the second mounting hole opening is further closed by a lid 28. The peripheral edge of the inner opening of the second mounting hole 24c is curved slightly inward toward the center of the second mounting hole 24c, and the movable locking sphere 26 'is formed.
Forms a retaining portion 24d which prevents the cylindrical member 24 from dropping from the cylindrical mounting portion 24 inward in the radial direction. Then, the movable locking sphere 2 retained in the retaining portion 24d is prevented.
The compression coil spring 27 is compressed and deformed by being sandwiched between the lid 6 and the lid 28, and the movable locking sphere 26 ′ is urged radially inward of the cylindrical mounting portion 24 by its resilient force, The movable locking sphere 26 'is connected to the retaining portion 24d.
, That is, at the position where the head of the movable locking sphere 26 ′ projects inward from the inner peripheral surface of the cylindrical mounting portion 24.

In the present invention, the fixed locking member and the movable locking member do not necessarily have to be spherical. For example, as shown in FIG.
May be attached to the first attachment hole 24b. However, by making the fixed locking member and the movable locking member spherical, the contact resistance with the tool body is reduced, and the operation becomes smoother. In addition, since the fixed locking sphere 26 and the movable locking sphere 26 'have the same shape, mass productivity is improved.

Next, an example of how to use the drilling tool will be described.

First, at the angular position where the front end of the first groove 15a in each locking groove 15 on the tool body 11 side and the two fixed locking spheres 26 on the blade 20 coincide with each other, the cylindrical mounting portion 24 is set. It fits outside the front end of the tool body 11. At this time, each of the fixed locking spheres 26 is attached to the first groove 1 of each locking groove 15.
5a penetrates in the tool axis direction and hits the end thereof.
Further, since the movable locking sphere 26 'is pushed from the inside by the outer peripheral surface of the small diameter portion 11e and is immersed in the second mounting hole 24c against the resilient force of the compression coil spring 27, the fitting operation is hindered. There is no.

Next, the tool body 11 is kept in the fitted state.
And the cutter 20 are relatively rotated (in the structure shown, the cutter 2
0, the tool body 11 is relatively rotated counterclockwise as viewed from the tip side of the tool body 11).
The fixed locking sphere 26 on the blade 20 side is made to penetrate into the second groove 15b in the circumferential direction. This intrusion causes the fixed locking sphere 26 to
At the time when the groove 15b has almost reached the end, the movable locking sphere 26 'on the blade 20 side is fitted into the detent recess 17 by the elastic force of the compression coil spring 27, and as a result, the tool body 1
The relative rotation between the blade 1 and the blade 20 is restricted. Due to this rotation, each fixed locking sphere 26 is brought into the second groove 1 of each locking groove 15.
5b, whereby the relative movement of the tool body 11 and the blade 20 in the axial direction is also restricted. That is, the blade 20 is fixed to the tool body 11,
The mounting is completed.

The drive connecting portion 11a of the tool body 11 is connected to a rotary drive (not shown) to drive the entire tool at high speed.
In this state, first, the drill blade 12a of the center drill 12 is pressed against the construction surface and propelled to determine the center position of the processing hole, and then the cutting blade 21 of the cutting tool 20 is pressed against the construction surface to perform the main processing. Is performed. Here, for example, as shown in FIG.
If the direction in which b extends from the end of the first groove 15a in the circumferential direction is designed to be opposite to the direction of the rotational drive of the tool body 11, the rotational resistance that the blade 20 receives from the work material will be reduced. This acts in a direction in which the fixed locking sphere 26 on the side is pressed against the end side of the second groove 15b, that is, it is a so-called tightening operation, so that the mounted state of the blade 20 is more reliably maintained.

Further, since a conventional set screw is not used for the mounting, even if vibration is applied to the blade 20 during construction, there is no inconvenience that the set screw is loosened by the vibration. Therefore, smooth construction without trouble can be continued.

Contrary to the above, to remove the blade 20 for the purpose of replacing the blade 20 or reversing the direction of the blade 20 (ie, using the cutting blade 21 on the opposite side), the reverse operation to the above is performed. do it. That is, each fixed locking sphere 26
Causes the tool body 11 and the blade 20 to rotate relative to each other in such a direction as to move backward in the second groove 15b (that is, approach the first groove 15a side), and further to cause each fixed locking sphere 26 to escape from the first groove 15a. By removing the cutting tool 20 from the tool body 11, the cutting tool 20 can be easily removed.

As described above, according to the drilling tool according to this embodiment, the cutting tool 20 can be attached to and detached from the tool body 11 by a few simpler operations than the conventional tool shown in FIG. And reliability in the mounted state is greatly improved. Moreover, the mounting structure of the cutting tool 20 in the drilling tool can be easily manufactured by, for example, the following method.

1) A through hole 24 is provided at an appropriate position of the cylindrical mounting portion 24.
a is provided.

2) A bush 32 as shown in FIG. 5A, for example, is inserted from the outside into the through hole 24a, and its tip is brought into contact with the inner peripheral surface facing the through hole 24a.

3) A drill 34 shown in FIG. 3A is inserted inside the bush 32, and a bottomed first mounting hole 24b is formed in the inner peripheral surface by the tip of the drill 34.

4) Pull out the drill 34 from the bush 32,
Next, the fixed locking sphere 26 is fitted into the mounting hole 24b through the bush 32. In the case of press-fitting, the fixed locking sphere 2 is inserted by pushing a push rod into the bush 32 or the like.
6 is applied from above (see the arrow in FIG. 3B).

According to such a manufacturing method, even in a narrow space in the cylindrical mounting portion 24, the mounting hole 24b is formed in the inner peripheral surface thereof.
In addition, the fixed locking sphere 26 can be provided without difficulty.

In the structure shown in FIGS. 1 to 5, if the fixed locking sphere 26 is pressed into a position where it comes into contact with the bottom of the first mounting hole 24b, the depth of the first mounting hole 24b can be set. Accordingly, the amount of protrusion of the fixed locking sphere 26 from the inner peripheral surface of the cylindrical mounting portion 24 can be accurately determined.

On the other hand, processing of the second mounting hole 24c and mounting of the movable locking sphere 26 'in the second mounting hole 24c can be easily performed by the following method.

5) A hole is drilled from the outside of the cylindrical mounting portion 24 with a drill having a substantially hemispherical tip, and a through hole, that is, a second mounting hole 24c is machined so that the retaining portion 24d remains at the inner end.

6) The movable locking sphere 26 'and the compression coil spring 27 are loaded into the second mounting hole 24c from the outside of the cylindrical mounting portion 24, and the opening of the second mounting hole on the outside is closed with the lid 28. . Since the compression coil spring 27 is sandwiched between the lid 28 and the movable locking sphere 26 ′, the compression coil spring 27 is compressed and deformed, and the movable locking sphere 2
A force is generated that urges 6 'radially inward of the cylindrical mounting portion 24.

According to this method, both the processing of the second mounting hole 24c and the mounting of the movable locking sphere 26 'and the compression coil spring 27 can be performed from outside the cylindrical mounting portion 24.

In addition, the present invention can take the following embodiments as examples.

(1) In the present invention, the specific shape and structure of the blade 20 are not limited. For example, FIG. 1 and the like show a double-edged tool 20 having cutting blades 21 at both front and rear ends.
The present invention is also applicable to the case where the single-edged blade 20 shown in FIG.

(2) The means for fixing the fixed locking member into the mounting hole 24b is not limited to press-fitting. For example, an adhesive may be used, or the mounting hole 24b may be a screw hole, and a male screw that can be screwed into the screw hole may be formed in the fixed locking member.
Even if the screw is loosened in such a screw structure, the displacement direction of the fixed locking member is a direction in which it projects inward, so that the engagement between the fixed locking member and the locking groove may be disengaged. There is no.

(3) In the present invention, the arrangement and number of the fixed locking members and the locking grooves are not limited. These may be singular,
Further, even in the case of a plurality, it is not always necessary to arrange them at equal intervals.

[0063]

As described above, according to the present invention, a through hole is provided in a cylindrical mounting portion of a blade, and a first hole is provided on an extension of an axial center of the through hole.
A fixing hole is provided and a fixed locking member is fixed to the mounting hole so that the fixed locking member can enter the first groove or the second groove in the locking groove on the tool body side in the axial direction and the circumferential direction, At the end of the intrusion, the relative rotation between the rotation preventing recess on the tool body side and the movable locking member on the blade side is restricted by engagement with the movable locking member. And the reliability in the mounted state can be improved, and the mounting structure of the blade can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional front view of a drilling tool according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional front view of a tool body of the drilling tool.

3A is a cross-sectional view taken along the line AA of FIG. 3B, and FIG. 3B is a front view showing a front end of a tool main body in the drilling tool.

FIG. 4 is a sectional view taken along line CC of FIG. 5;

FIG. 5 is a cross-sectional view of a cylindrical attachment portion of a cutting tool in the drilling tool.

FIG. 6 is a cross-sectional view showing an example in which a fixed locking member of the blade is pin-shaped.

FIGS. 7 (a) and 7 (b) are cross-sectional front views showing a manufacturing process of a cutting tool of the drilling tool.

8A is a cross-sectional front view showing an example of a conventional drilling tool, and FIG. 8B is a cross-sectional view taken along line BB of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Tool main body 12 Center drill 15 Locking groove 15a 1st groove 15b 2nd groove 17 Detent recess 20 Cutting tool 21 Cutting blade 24 Cylindrical mounting part 24a Through hole 24b First mounting hole 24c Second mounting hole 26 Fixed locking sphere 26 'movable locking sphere 27 compression coil spring (spring member) 28 lid 29 fixed locking pin 34 drill (another drilling tool)

Claims (13)

[Claims] 1. A tool main body connected to a drive source, and a cylindrical mounting portion fittable to the outside of the tool main body, and the tool is configured to rotate integrally with the tool main body in the fitted state. In a drilling tool having a blade fixed to the main body,
A through hole is provided in the cylindrical mounting portion so as to penetrate through the cylindrical mounting portion in a radial direction, and a first mounting hole is provided on an inner peripheral surface of the cylindrical mounting portion at a position located on an axial extension of the through hole. A fixed locking member is fixed in the first mounting hole so as to protrude inward from the inner peripheral surface of the cylindrical mounting portion, and the mounting hole is formed in the inner peripheral surface of the cylindrical mounting portion. A second mounting hole is provided at a location different from the circumferential direction,
A movable locking member movable in the radial direction of the cylindrical mounting portion in the second mounting hole, and the movable locking member is urged radially inward of the cylindrical mounting portion to move the movable locking member. A biasing means for projecting inward from an inner peripheral surface of the cylindrical mounting portion is attached, and the fixed locking member is attached to an outer peripheral surface of the tool main body where the cylindrical mounting portion is fitted. A first groove which can intrude into the rear side of the tool body along the axial direction from the front end of the first groove and a second groove which allows the fixed locking member to intrude in the circumferential direction of the tool main body from the end of the first groove are continuous. A locking groove, a detent recess for restricting relative rotation between the tool body and the blade by engaging with the movable locking member at a position where the fixed locking member enters the second groove of the locking groove; A drilling tool characterized by having a hole. 2. The drilling tool according to claim 1, wherein at least one of the fixed locking member and the movable locking member is a sphere. 3. The drilling tool according to claim 2, wherein the fixed locking member and the movable locking member are spherical bodies having the same shape. 4. The drilling tool according to claim 1, wherein the first mounting hole is a hole with a bottom, and the fixed locking member reaches a position where the fixed locking member abuts the bottom. Is inserted and fixed in the first mounting hole. 5. The drilling tool according to claim 1, wherein the fixed locking member is press-fitted into the first mounting hole. 6. The drilling tool according to claim 1, wherein the first mounting hole and the fixed locking member are provided at a plurality of positions different in a circumferential direction. tool. 7. The drilling tool according to claim 1, wherein a direction in which the second groove extends from the first groove is set to a direction opposite to a direction in which the tool body is rotationally driven. A drilling tool. 8. The drilling tool according to claim 1, wherein the movable locking member is provided at an inner end of the second mounting hole from the second mounting hole to the inside of the cylindrical mounting portion. A drilling tool having a retaining portion for preventing falling off. 9. The drilling tool according to claim 1, wherein the tool body is provided with a center drill at a tip end thereof, and the cutting tool is provided around the center drill. A drilling tool having a substantially cylindrical shape that is coaxially covered, and having a cutting blade at a tip end thereof. 10. The drilling tool according to claim 9, wherein
A drilling tool, characterized in that the cutting tool has the cutting blades at both ends and a cylindrical mounting portion having a larger thickness than other portions at an intermediate portion. 11. The method for manufacturing a drilling tool according to claim 1, wherein a through-hole is provided in the cylindrical mounting portion of the blade in a radial direction through the cylindrical mounting portion.
Another drilling tool is inserted into the through hole, and the first mounting hole is machined in the inner peripheral surface of the cylindrical mounting portion by the drilling tool. The first mounting hole is inserted into the first mounting hole from outside the cylindrical mounting portion. A method for manufacturing a drilling tool, comprising inserting and fixing a fixed locking member through the through hole. 12. The method for manufacturing a drilling tool according to claim 11, wherein the fixed locking member is press-fitted into the first mounting hole. 13. The method for manufacturing a drilling tool according to claim 8, wherein a through hole radially penetrating the cylindrical mounting portion as the second mounting hole is formed so that the retaining portion remains. Then, a movable locking member and a spring member as a biasing means thereof are loaded into the second mounting hole, and then the outer opening of the second mounting hole is closed with a lid. A method for manufacturing a drilling tool, characterized in that a spring member is sandwiched and deformed by compression, and the movable locking member is urged radially inward of a cylindrical mounting portion by the elastic force of the spring member.