JPS6236566Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a drilling drill device used for drilling large-diameter holes.

<Prior art> Conventionally, as a drilling drill device, the Utility Model Publication No. 51-53514
No. 52-18791, Japanese Patent Publication No. 52-37236, etc. These have a cylindrical body with a cutting edge at the end, and a shank with an engaging part that cannot be moved in the axial direction in the middle part is inserted and removably inserted on the same axis, and a tapered surface is formed on the periphery of the cylindrical body. At the same time, a pressing body is screwed into the tip of the shank, and the pressing body presses the engaging portion of the shank and the inner peripheral surface of the cylinder through the tapered surface, thereby bringing the cylinder and the shank into pressure contact. It is something that will be done. Then, the shank is interlocked and connected to a rotating power source such as an electric drill, and the rotation is transmitted to the cylindrical body to open a large diameter hole using the cutting blade at the end.

<Problems to be solved by the invention> In the above-mentioned drilling drill device, the cutting edge of the cylinder body is polished, the blade is chipped at the work site, the material of the workpiece is different, etc. often need to be removed and replaced. However, the load torque when opening the hole is transmitted to the pressing body through the cylindrical body, and as a result, the pressing body is screwed into the tip of the shank more than necessary and presses the engaging portion with a large force. In this case, a large axial force acts on the threaded portion where the shank and the pressing body are threaded together, and a large force is required to release the threaded engagement. Therefore, in the past, it was not possible to unscrew the threaded connection using tools such as ordinary spanners or wrenches, and tools such as spanners that were engaged with the shank or cylindrical body after fixing the drilling drill device with a vise etc. It is extremely inconvenient as it requires work similar to hitting the cylinder with a hammer, and there is a risk of damage due to the large impact force applied, and it is difficult to replace the cylinder at work sites that do not have a vise etc. It was not easy to use because it could not be used.

In view of the above, an object of the present invention is to provide a drilling drill device that does not require a large force to release the threaded engagement between the shank and the pressing body, and can easily release the pressure contact between the cylindrical body and the shank. shall be.

<Technical means for solving the problems> The technical means adopted by the present invention to solve the problems of the prior art and achieve its purpose are characterized by the fact that a cutting edge is attached to the end. A shank, which has an engaging part that cannot be moved in the axial direction in the middle, is inserted into the cylindrical body so that it can be freely inserted and removed on the same axis. In the drilling drill device, the engaging portion of the shank and the inner circumferential surface of the shank are pressed by the pressing body through the tapered surface, thereby bringing the shank and the shank into pressure contact. In order to reduce the pressing force exerted by the pressing body on the mating portion, the engaging portion can be separated from the pressing force receiving position.

<Operation> When the engaging portion of the shank is separated from the position where the pressing force is received by the pressing body, the pressing force is reduced.
In this case, the axial force acting on the threaded portion of the threaded portion between the tip of the shank and the pressing body is also reduced, and the threaded engagement can be released without requiring a large force.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.
In the drilling drill device 1 shown in FIGS. 1 to 3, 2
is a cylindrical body. A plurality of cutting blades 3 are fixed to both ends of the cylindrical body 2 so as to slightly protrude from each end face, outer peripheral surface, and inner peripheral surface of the cylindrical body 2. Cutting blade 3
The number, shape, arrangement, and amount of protrusion are appropriately determined depending on the workpiece. Further, a semicircular notch 4 for releasing chips is provided adjacent to each cutting edge 3.

Reference numeral 5 denotes a shank, the outer periphery of which is formed into a male threaded portion 6, and the rear end 5c is approximately prismatic in shape for connection to a rotary power source such as an electric drill. Further, the midway portion 5b has a cylindrical shape with a slightly larger diameter, and a tapered hole 7 is passed through it. A screw hole 8 is provided in front of the tapered hole 7 and communicates with a tool attachment hole 9 drilled from the front end surface of the shank 5. As a result, the drill 10 inserted into the tool mounting hole 9
A set screw 12 screwed into the screw hole 8 is engaged with the recess 11 at the rear end to prevent the drill 10 from rotating and coming off.

Reference numeral 13 denotes a taper pin (engaging portion), which is fitted into the taper hole 7 of the shank 5 so as to be freely insertable and removable, with both ends protruding.

14 is a collar, which is the middle part 5b of the shank 5;
The pin 13 is fitted onto the outside of the pin 13 so as to be movable in the axial direction, and its rear end surface is joined to the taper pin 13.

Reference numeral 15 designates a disc-shaped shank holder, the outer periphery of the rear end of which is a flange 15a, a protrusion 15b provided at the center of the rear end surface, and a surface 15b' for engaging a tool such as a spanner on the outer periphery of the protrusion 15b. ing. In this shank holder 15, 16 is a shank through hole penetrated through the center, and a stepped portion 16 is provided on the inner peripheral surface of the shank hole.
a is formed. Further, reference numerals 17, 17 are a pair of spring pin holding holes, which are penetrated at the central distribution position, and spring pins 18, 18 are inserted and held therein.

The shank 5 is inserted into the shank through hole 16 so as to be relatively rotatable and movable in the axial direction.
5b is brought into contact with the rear end surface.

Reference numeral 19 denotes an expansion ring which is separated at one position 20 on its outer periphery and is elastically expandable and contractable in the radial direction.
A flange 1 is provided on the outer periphery of the rear end of the expansion ring 19, which comes into contact with the end surface of the cylinder body 2 when the expansion ring 19 is fitted into the cylinder body 2.
9a is provided. At this time, since the cutting edge 3 protrudes from the end surface of the cylinder 2, a concave groove 21 is formed in the flange 19a to avoid interference with the cutting edge 3.
are formed in corresponding positions. In addition, in this embodiment, since the cutting edge 3 also protrudes from the inner peripheral surface, the groove 2 is located at a position corresponding to the cutting edge on the outer periphery of the expansion ring 19.
At the same time as the groove 1 is formed, an relief groove 22 is also provided to avoid interference therebetween. The front end of this escape groove 22 is the notch 2
It is said to be 3. The inner circumferential surface of the front end of the expansion ring 19 is formed into a tapered surface 24 that is gradually thinned toward the front.

The expansion ring 19 is fitted around the outer periphery of the shank holder 15 so as to be relatively rotatable, and
The rear end surface of the flange 19a is the shank holder 1.
The front end surface of the flange 15a of No. 5 is brought into contact with the front end surface of the flange 15a.

Reference numeral 25 denotes a disc-shaped pressing body, and the outer peripheral surface of the rear end thereof is formed into a tapered surface 26 whose diameter gradually decreases toward the rear so as to be inscribed in the tapered surface 19a of the expansion ring 19. Further, a female threaded portion 27 is provided in the center to be screwed into the male threaded portion 6 at the tip of the shank 5, and an engagement hole 28 for the spring pins 18, 18 is provided at the central distribution position.
28 is penetrated.

Then, the spring pins 18, 18 inserted and held in the shank holder 15 are inserted into the engagement holes 28, 28 of the pressing body 25, so that the pressing body 25 and the shank holder 15 cannot rotate relative to each other, and the male of the shank 5 Threaded portion 6 and female threaded portion 27 of pressing body 25
and are positioned in the screwing position, and thereby the pressing body 2
5. The tapered surface 26 on the outer periphery of the expansion ring 19 and the tapered surface 24 on the inner periphery of the expansion ring 19 are brought into contact. In this state, the cylindrical body 2 is fitted onto the expansion ring 19 so that the rear end surface of the cylindrical body 2 and the front end surface of the flange 19a of the expansion ring 19 are brought into contact. At this time, the cutting edge 3 of the cylinder 2 is located inside the groove 21 of the flange 19a. Then, Shank 5
is rotated relative to the shank holder 15, and the pressing body 25 is screwed into the tip of the shank 5. Then, the pressing body 25 passes through the expansion ring 19, the shank holder 15, and the collar 14 to the taper pin 1.
Press 3. Further, the expansion ring 19 is
5 and the shank holder 15, the pressing body 25 expands in the radial direction, and the pressing body 25 presses the inner circumferential surface of the cylinder 2 through its tapered surface 26 and the tapered surface 24 of the expansion ring 19. It will put pressure on you. As a result, when a hole is opened by the drilling drill device 1 in which the cylinder body 2 and the shank 5 are pressed together, load torque is transmitted to the pressing body 25 through the cylinder body 2.
Then, the pressing body 25 rotates with respect to the shank 5 in the screwing direction. As a result, the pressing body 25 presses the taper pin 13 with a force larger than necessary.

On the other hand, the inner circumferential surface of the cylinder 2 is further pressed through the tapered surface 26 of the pressing body 25 and the tapered surface 24 of the expansion ring 19, but at this time, the shank holder 15 The blade 3 will not be damaged. That is, since the cutting edge 3 is located inside the groove 21 provided in the flange 19a of the expansion ring 19, the shank holder 15 is moved relative to the cylindrical body 2 due to the load torque due to cutting and the rotational force of the rotational power source. Even if the shank holder 15 rotates, the cutting blade 3
There is no direct collision with the cutting edge of the blade, so there is no risk of damage as in the conventional case.

To release the pressure contact between the shank 5 and the cylinder body 2, first, the small diameter end face of the taper pin 13 is struck with a hammer or the like to move it in the removal direction. This causes the taper pin 13 to move backward away from the position where it receives the pressing force from the pressing body 25, thereby reducing the pressing force. This causes shank 5
Threaded portions 6, 27 of the threaded portion between the tip and the pressing body 25
The axial force acting on the shank 5 and the cylindrical body 2 is also reduced, so that the screw engagement can be released without requiring a large force, and the pressure contact between the shank 5 and the cylinder body 2 is released.

Note that to receive the pressing force of the pressing body 25, not only the taper pin 13 but also an eccentric pin 13' as shown in FIG. 4 may be used. This is Shank 5
The base 13a is rotatably inserted into the pin hole 7' of the base 13a.
and a pressure receiving part 13b extending protruding from the shank 5 with the axis of the base part 13a and the axis thereof being eccentric.
and a tool hooking part 13c extending from the upper end of the pressure receiving part 13b.By rotating this part, the pressure receiving part 13b is separated rearward from its pressing force receiving position, and the pressing body 25 This reduces the pressing force caused by

Also, a straight pin may be used instead of the taper pin 13, but the straight pin cannot be separated from its pressing force receiving position unless it is completely removed from the pin hole of the shank. It is better to use

Furthermore, the cylindrical body 2 does not have the cutting blades 3 at both ends as described above, but may have the cutting blades 3 only at the tip. Further, there is no need to attach the drill 10 to the shank 5.

In order to press the taper pin (engaging portion) 13 and the inner circumferential surface of the cylinder body 2 by the pressing body 25, the expansion ring 19, the shank holder 15, the collar 1, etc.
4 is not necessarily necessary, and these may be integrally molded as a cylindrical body 2 as shown in FIG.

<Effects> According to the present invention, in order to press the cylinder having a cutting edge and the shank, the pressing body screwed into the tip of the shank is connected to the inner peripheral surface of the cylinder and the engaging part in the middle of the shank via a tapered surface. In a drilling drill device that presses a shank, the engaging portion can be separated from a position where the pressing force is received by the pressing body, thereby reducing the force of the pressing force, thereby preventing the screwing of the shank and the pressing body. The axial force acting on the threaded part of the part can also be reduced, and even if a large axial force is applied to the threaded part due to the load torque caused by cutting, the screwing can be easily released and the shank and cylinder can be separated. It is easy to use when replacing the cylinder or polishing the cutting blade at the work site.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a drilling drill device according to an embodiment of the present invention, Fig. 2 is an exploded perspective view of the same, Fig. 3 is a rear view of the same, and Fig. 4 A is an engaging part according to another embodiment. FIG. 4B is a longitudinal sectional view of the same main part, and FIG. 5 is a longitudinal sectional view of the main part according to still another embodiment. 1...Drilling drill device, 2...Cylinder body, 3...Cutting blade,
5...Shank {5b...midway part, 5c...tip}, 13...engaging part, 24, 26...tapered surface, 25...pressing body.

Claims (1)

[Scope of utility model registration request] A cylindrical body 2 having a cutting edge 3 at an end, and a shank 5 having an engaging portion 13 that cannot be moved in the axial direction at a midway portion 5b.
are inserted removably on the same axis, and tapered surfaces 24 and 26 are formed at the inner peripheral position of the cylindrical body 2, and a pressing body 25 is screwed into the tip 5c of the shank 5. In the drilling drill device 1 in which the engaging portion 13 of the shank 5 and the inner circumferential surface of the cylinder 2 are pressed together through the surfaces 24 and 26, the cylinder 2 and the shank 5 are brought into pressure contact. A drilling drill device characterized in that the engaging part 13 can be moved away from its pressing force receiving position in order to reduce the pressing force exerted on the part 13 by the pressing body 25.