JPS6314973Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a drilling drill device that is used to open a large-diameter hole and is equipped with a cylindrical body provided with cutting edges at both ends.

<Prior Art> As a drilling drill device equipped with a cylindrical body provided with cutting blades at both ends, there is a device devised by the applicant of the present invention. This is designed to extend the life of the cylinder and increase work efficiency by providing cutting edges at both ends of the cylinder, as well as to better transmit the cutting torque during cutting to the cylinder. .

As shown in FIG. 5, this consists of a cylindrical body 102 having cutting edges 103 protruding from both end faces, a ring 119 that can be expanded and contracted in the radial direction, a shank holder 115 integrally molded with this ring 119, and a The main structure includes a shank 105 having an engaging part 113 that cannot be moved in the axial direction, and a pressing body 125. The ring 119 is fitted into the rear end of the cylindrical body 102 and is brought into contact with the rear end surface of the cylindrical body 102 via the flange 119a. In order to prevent interference with the cutting blade 103, a groove 121 is formed in the flange 119a so that the cutting blade 103 is located inside the groove. The shank 105 is inserted into the shank holder 115, and its engaging portion 11
3 is brought into contact with the rear surface of the shank holder 115. The pressing body 125 is brought into contact with the inner periphery of the ring 119 via tapered surfaces 124 and 126. and,
When the pressing body 125 is screwed into the tip of the shank 105, the ring 119 is expanded through the tapered surfaces 124 and 126, and the inner peripheral surface of the cylinder 102 and the ring 119 are pressed into contact with each other in the radial direction. Thereby, cutting torque can be transmitted from a drill or the like connected to the shank 105 to the cylindrical body 102.

In the conventional device described above, the pressing body 125 is screwed into the shank 105 by first rotating the two 125, 105 relative to each other using a tool such as a wrench. However, with a wrench or the like, the pressing body 125 cannot be sufficiently screwed into the shank 105, and the pressure contact between the cylinder body 102 and the ring 119 and the pressure contact between the shank holder 115 and the engaging portion 113 cannot be made sufficiently. . Therefore, the pressing body 125 is screwed into the shank 105 using cutting torque.

That is, the shank holder 115 and the engaging portion 1
13, the pressing body 125 can rotate relative to the shank 105 in the screwing direction. Therefore, when cutting is performed in this state, the cutting torque is transferred from the cylinder 102 to the ring 119 and the tapered surface 124. , 126 to the pressing body 125, and the pressing body 125 is screwed into the shank 105 with relative rotation. As a result, the shank holder 115 and the engaging portion 113 are brought into pressure contact, and the ring 11
9 and the inner circumferential surface of the cylindrical body 102 are sufficiently pressed to ensure good transmission of cutting torque.

<Problems to be solved by the invention> If the pressure contact between the cylindrical body 102 and the ring 119 is insufficient, the pressing body 1 will be damaged due to cutting torque as described above.
25 and the shank 105, there is a possibility that the cylindrical body 102 and the ring 119 may also rotate relative to each other. This is ring 119 and shank holder 1
15 is integrally molded in conventional models, so when the shank holder 115 tries to rotate relative to the cylinder 102 due to cutting torque, the ring 119 integrated with the shank holder 115 also tries to rotate relative to the cylinder 102. This is to do so.
When the cylindrical body 102 and the ring 119 rotate relative to each other, the cutting edge 103 in the groove 121 of the flange 119a of the ring 119 may collide with the groove 121 and be damaged.

The present invention aims to solve the above problems.

<Means for Solving the Problems> The feature of the present invention in order to solve the problems of the prior art is that cutting blades 3 are provided at both ends of the cylinder 2 so as to protrude from the end face of the cylinder 2. A ring 19, which has a flange 19a that contacts the rear end surface of the cylinder body 2 and is expandable and contractible in the radial direction, is fitted inside the cylinder body 2, and the ring 19 has a tapered surface 24,
26 is formed, and a concave groove 21 is formed in the flange 19a so that the cutting blade 3 is located inside the ring 19 to avoid interference with the cutting blade 3.
Through a shank holder 15 that is separate from the ring 19 that contacts the rear end surface, the shank 5, which has an engaging part 13 that cannot be moved in the axial direction at the midway part 5b, can be freely inserted into and removed from the cylinder 2 on the same axis. The pressing body 25 inserted and screwed into the tip of the shank 5 engages the inner circumferential surface of the cylinder body 2 and the engaging portion 13 via the tapered surfaces 24 and 26.
is at the point where the shank 5 and the cylinder body 2 are pressed together.

<Function> The shank holder 15 and the ring 19 are separate bodies, and are in contact with each other via the end faces of the respective flanges 15a and 19a. Therefore, even if the shank holder 15 and the cylindrical body 2 rotate relative to each other due to cutting torque, the shank holder 15 and the ring 19 can rotate relative to each other, so that the relative rotation between the cylindrical body 2 and the ring 19 can be prevented.

<Example> Embodiments of the present invention will be described below with reference to 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. The number, shape, arrangement, and protrusion amount of the cutting blades 3 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 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. Also, the middle part 5
b 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 set screw 12 is screwed into the screw hole 8 into the recess 11 at the rear end of the drill 10 inserted into the tool attachment hole 9.
are engaged 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 the 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 is a flange 15a, a protrusion 15b is provided at the center of the rear end surface, and a surface 15b' for engaging a tool such as a spanner is formed 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 to 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 a position 20 on its outer periphery so as to be elastically expandable and contractable in the radial direction.
The expansion ring 19 has a flange 1 on the outer periphery at the rear end thereof, which contacts the end face of the cylindrical body 2 when the expansion ring 19 is fitted inside the cylindrical body 2.
In this case, since the cutting blade 3 protrudes from the end face of the cylindrical body 2, a concave groove 21 is provided in the flange 19a to prevent interference with the cutting blade 3.
In this embodiment, the cutting edge 3 also projects from the inner peripheral surface, so that the groove 2 is formed at the cutting edge corresponding position on the outer periphery of the expansion ring 19.
At the same time as forming the recess 21, a relief groove 22 is formed to avoid interference therebetween.
The inner peripheral surface of the front end of the expansion ring 19 is formed as a tapered surface 24 which is gradually thinner 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 the press body 25 are positioned in the screwing position.
The tapered surface 26 on the outer periphery 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, the 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 includes the expansion ring 19, the shank holder 15, and the collar 14.
The taper pin 13 is pressed in the axial direction through the . Further, since the expansion ring 19 is sandwiched between the pressing body 25 and the shank holder 15, it expands in the radial direction, and the pressing body 25 connects its tapered surface 26 with the tapered surface 24 of the expansion ring 19. The inner circumferential surface of the cylinder body 2 is pressed in the radial direction through the cylinder body 2. When a hole is opened in this state, cutting torque is transmitted from the cylinder 2 to the pressing body 25 via the ring 19 and the tapered surfaces 24 and 26. Then, the pressing body 25 rotates with respect to the shank 5 in the screwing direction. As a result, the inner circumferential surface of the cylinder 2 and the ring 9 are firmly pressed against each other, and the cutting torque is efficiently transmitted.

On the other hand, since the ring 19 and the shank holder 15 are separate bodies and come into contact through the end faces of their flanges 15a and 19a, the cutting torque causes the cylinder 2 and the shank holder 15 to rotate relative to each other. Also, the shank holder 15 and the ring 19 can rotate relative to each other. This can prevent relative rotation between the ring 19 and the cylindrical body 2, and can prevent the cutting edge 3 in the groove 21 of the ring flange 19a from colliding with the groove 21 and being damaged.

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. As a result, the threaded portions 6 and 2 of the threaded portion between the tip of the shank 5 and the pressing body 25
The axial force acting on 7 will also be reduced,
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 includes a base 13a which is rotatably inserted into the pin hole 7' of the shank 5;
The axis of the base 13a and the axis thereof are eccentric and extend from the shank 5 in a protruding manner. A pressure receiving part 13b extends from the upper end of the pressure receiving part 13b.
By rotating this, the pressure receiving part 13b is separated rearward from its pressing force receiving position, and the pressing force by the pressing body 25 is reduced.

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

Further, there is no need to attach the drill 10 to the shank 5.

<Effect of the invention> According to the invention, the ring 19 and the shank holder 15 are separate bodies, and each flange 15a,
Since the contact is made through the end face of 19a,
The cylinder body 2 and the shank holder 15 are separated by cutting torque.
Even if the shank holder 15 and the ring 19 rotate relative to each other, the shank holder 15 and the ring 19 can rotate relative to each other. This can prevent relative rotation between the ring 19 and the cylindrical body 2,
The cutting edge 3 in the groove 21 of the ring flange 19a is
It is possible to prevent damage caused by collision with the groove 21.

[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. 4B is a longitudinal sectional view of the same essential part, FIG. 5A is a longitudinal sectional view of the drilling drill device according to the conventional example, FIG. It is a perspective view of the same shank holder. 2... Cylindrical body, 3... Cutting blade, 5... Shank, 5
b... Midway part, 13... Engaging part, 15... Shank holder, 19... Expansion ring, 19a... Flange, 21... Concave groove, 24, 26... Tapered surface, 25... Pressing body .

Claims (1)

[Scope of utility model registration request] Cutting blades 3 are provided at both ends of the cylinder 2 to protrude from the end face of the cylinder 2, and a ring 19 that has a flange 19a that comes into contact with the rear end face of the cylinder 2 and is expandable and contractible in the radial direction is attached to the cylinder 2. Tapered surfaces 24 and 26 are formed on the inner periphery of the ring 19, and a groove is formed on the flange 19a so that the cutting edge 3 is located inside the ring 19 to avoid interference with the cutting edge 3. 2
1 is formed, and a shank 5 having an engaging part 13 that is immovable in the axial direction at a midway part 5b is attached to the cylinder body 2 through a shank holder 15 that is separate from the ring 19 and contacts the rear end surface of the ring 19. The inner circumferential surface of the cylinder 2 and the engaging portion 13 are pressed through the tapered surfaces 24 and 26 by a pressing body 25 that is inserted and removably inserted around the axis and screwed into the tip of the shank 5. A drilling drill device characterized in that a shank 5 and a cylindrical body 2 are brought into pressure contact with each other.