WO2010084551A1 - Core drill - Google Patents

Abstract

Provided is a core drill capable of holding a cut-out core in the hollow portion of the drill body so as to prevent the cut-out core from falling down.  The core drill (A) of the present invention comprises a cylindrical drill body (1), cutting teeth (2) arranged at the lower end of the drill body (1) and a shank (4)disposed at the upper end of the drill body (1) to be held by a drilling machine.  The core drill is further provided with a yieldable pressing member (6) disposed in the hollow portion of the core drill (1) projecting radially inwardly and yieldable radially outwardly.

Description

Core drill

発 明 The present invention relates to a core drill including a metal borer.

Conventionally, when drilling a relatively large-diameter hole, a core drill is used because of the high drilling efficiency and the edge of the drilled hole. As such a core drill, what is called a metal bore drilled in an iron plate or the like, or a core drill drilled in wood, resin, or the like, or a core drill drilled in a composite material in which the surface is metal and wood is used for the inner layer, Or there exists a core drill etc. which drill a stone, concrete, etc. (patent document 1).

Such a core drill cuts only the outer peripheral portion of the hole to be drilled, and drills a cylindrical hole without cutting the inner region. For this reason, when drilling is completed, a cylindrical cutout waste material having an outer diameter substantially equal to the inner peripheral diameter of the core drill remains inside the core drill.

Japanese Patent Publication 2001-138120.

By the way, in recent years, environmental issues have been discussed in all fields, and improvements have been sought to make them environmentally friendly.

As a part of this, for example, when drilling a bridge structure or the like installed in a river using the core drill, in the conventional core drill, when the drilling is completed, a cylindrical cut-out remaining inside the core drill In many cases, the waste material had fallen into rivers, riverbeds, etc. due to the gravity of the waste material.
In particular, in the case of drilling in the downward direction, it has been overlooked that it falls downward simultaneously with the completion of drilling.

However, if cut-out scraps, such as metal blocks, are discarded in rivers, riverbeds, etc., the natural environment will be affected.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a core drill that can reliably hold the cut-out scrap material inside the core drill after completion of drilling, and prevent the downward fall or the like. And

In order to solve the above problems, a core drill according to the present invention includes a cylindrical core body, a cutting blade disposed at a lower end of the core body, and a drilling device disposed on an upper end surface of the core body. In a core drill having a shank portion for
The inner peripheral surface of the core body is provided with a pressing portion that protrudes toward the inner diameter in the radial direction of the core body and that is elastically deformed on the outer diameter to be deformable.

Thus, according to the core drill according to the present invention configured as described above, in the drilling process, a cylindrical cut waste material is formed inside the core body of the core drill as the drilling proceeds. The columnar cut waste material is pressed and held by the pressing portion toward the center of the core body. For this reason, even when the drilling operation is completed, the cut-out scrap material is held and held inside the core body of the core drill.

Therefore, if the cylindrical cut waste material is taken out from the core body of the core drill after the drilling operation is completed and treated as a predetermined waste, there is no influence on the environment.

Further, in the core drill, a recess having an inner peripheral surface recessed in an outer diameter direction is formed at a position spaced from the distal end of the inner peripheral surface toward the base end side, and at least one of the pressing members serving as the pressing portion is formed in the recess. If it arrange | positions so that a part may protrude further to an internal-diameter side from the said internal peripheral surface, while having the said effect | action, it becomes a preferable structure at the point which can position the said press member in the longitudinal direction of a core body further.

Further, in the core drill, when the pressing member is configured by a cylindrical or partially cylindrical leaf spring, a simple and easy maintenance and highly reliable configuration can be realized.

Further, in the core drill, the pressing member is formed in a portion where the maximum diameter portion of the winding diameter is equal to the inner peripheral diameter of the core body and the minimum diameter portion of the winding diameter is biased toward the center side from the tip portion. You may comprise with the coil spring of a form which is.

Further, in the core drill, when an opening is provided in a part of the core body and the cutting waste material retained inside the core body is pressed from the opening toward the distal end of the core body, the cutting is performed. It is possible to realize a configuration in which waste materials can be easily taken out from the core body.

According to the core drill according to the present invention configured as described above, it is possible to realize a core drill that can reliably hold the cut waste material inside the core body even when the drilling is completed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole structure of the core drill concerning one Example of this invention, and is a figure which shows an internal structure by cut | disconnecting half from a centerline. FIG. 2 is a partial enlarged cross-sectional view showing an enlarged part of an inner peripheral surface of a core body in which the pressing member is arranged in order to show an arrangement state of pressing members constituting the pressing unit shown in FIG. 1. FIG. 3 is a partial cross-sectional view of the core drill shown in FIGS. 1 and 2 when a drilling operation is performed on a drilled workpiece and the drilling is completed. It is a figure which shows the state which pulled out this core drill from the state in which a core drill is located in the to-be-punched object shown in FIG. 3 with the cutting waste material retained in the inside of a core body. FIG. 5 is a diagram showing a configuration of a core drill according to another embodiment of the present invention, which is different from the core drill shown in FIGS. is there. FIG. 6 is a partially enlarged cross-sectional view showing an enlarged part of the inner peripheral surface of the core body in which the pressing member is arranged in order to show the arrangement state of the pressing member shown in FIG. 5. It is the figure shown in the state which expand | deployed the leaf | plate spring shown in FIG. It is the figure which looked at the leaf | plate spring shown in FIG. 7 from the side. It is a perspective view which shows the state which curved the leaf | plate spring shown in FIG. 7, FIG. 8 in substantially cylindrical shape. It is the figure which showed the state which expand | deployed the leaf | plate spring concerning a form different from FIG. 7 which comprises a press member. It is a figure which shows the Example which provided the recessed part which arrange | positions a pressing member in the multiple places of the longitudinal direction of a core drill, and is a figure which shows an internal structure by crossing a half from a centerline. It is a figure which shows the different Example which provided the recessed part for arrange | positioning the press member which consists of a rectangular-shaped leaf | plate spring in the multiple places of the circumferential direction of a core drill, It is a figure which shows an internal structure by cut | disconnecting half from a centerline is there. It is a figure which shows the different Example comprised by denting the wall surface of a core drill to an inner-diameter direction, and is a figure which shows an internal structure by cut | disconnecting half from a centerline. It is sectional drawing which carried out the cross section of the core drill in this recessed part which shows the recessed part used as the press part shown in FIG.

Hereinafter, the present invention will be specifically described with reference to the drawings based on examples.

In FIG. 1, A is a core drill, and this core drill A has a cylindrical core body 1 and a plurality of cutting blades 2 formed at the tip of the core body 1 (left end in FIG. 1). Then, the said cutting blade 2 is comprised from the cemented carbide tip made into the block shape. A thick portion 1a configured to protrude outward is formed at the distal end portion (left end portion in FIG. 1) of the core body 1, and the thick portion 1a is formed by a cut made of the carbide chip. In order to plant the blades 2, a plurality of recesses opened toward the tip are formed.

The cutting edge 2 protrudes outward from the outer diameter end of the core body 1 and protrudes from the inner diameter end of the core body 1 toward the inner diameter. Further, the cutting edge 2 is further forward from the tip of the core body 1 (downward in FIG. 1). ) Is implanted in the recess.

In addition, each cutting portion 2 implanted in the core body 1 has a front portion in the rotation direction (upward in FIG. 1), that is, each front portion of the rake face 2a of each cutting blade 2 respectively. In order to discharge the chips cut by the cutting blade 2 to the outside of the core body 1, that is, between the outer peripheral surface 1A of the core body 1 and the inner peripheral surface of the hole to be drilled, Is formed.

Further, a long hole 3 penetrating the core body 1 in the thickness direction is formed at a central portion in the longitudinal direction (axial direction: lateral direction in FIG. 1) of the core body 1.
Further, a shank portion 4 made of a cylindrical body is provided integrally and concentrically with the core body 1 at the base end (upper end in FIG. 1) of the core body 1.
And it fixes to the outer peripheral surface 4F of the said shank part 4 for attaching and fixing so that it may rotate in unison with the attachment part (chuck part) of drilling apparatuses (not shown), such as an electric drill. A flat surface (fixed portion) 4a is formed.

In this embodiment, the inner peripheral surface 1F of the core body 1 has a circular cross section, and the base body 1F extends from the tip in the longitudinal direction of the inner peripheral surface 1F (longitudinal direction of the core drill A). A recessed portion 1B that is recessed toward the outer diameter side is formed at a position separated toward the end, for example, at a substantially central portion in the longitudinal direction.
The concave portion 1B has a form as shown in FIG. 9 and is a leaf spring that protrudes inward at the central portion in the longitudinal direction (lateral direction in FIGS. 1 and 2) and is curved in a substantially cylindrical shape. A pressing portion is formed by disposing the pressing member 6. In this embodiment, the pressing member 6 is formed in a pair of radial directions between the concave portion 1B which is a part of the inner peripheral surface 1F and another portion of the inner peripheral surface 1F adjacent thereto. The step member 7 is engaged and held so that the pressing member 6 does not move more than a predetermined amount in the longitudinal direction.
Further, at least a part of the pressing member 6, in this embodiment, the central portion 6c in the longitudinal direction protrudes toward the inner diameter side (left side in FIG. 2), and the protruding portion is the inner peripheral surface. It protrudes further to the inner diameter side from a portion other than the concave portion 1B of 1F, in particular, a portion other than the concave portion 1B of the inner peripheral surface 1F located at the tip side from the concave portion 1B. And the inclined surface 6b is formed in the both sides of the longitudinal direction of the said protrusion part.

The leaf spring constituting the pressing member 6 has a rectangular shape in plan view as shown in FIG. 7, and a round shape in side view as shown in FIG. As shown in FIG. 2 and the like, in a curved state, it is performed by mounting the concave portion 1B on the inner peripheral surface 1F.
Further, as another embodiment of the pressing member constituting the pressing portion, a shape in which notches 106a are provided at appropriate intervals in the upper and lower portions of the rectangular shape in plan view of the leaf spring as shown in FIG. The pressing member 106 may form a pressing portion.
Further, as a pressing member constituting the pressing portion of another embodiment, although not shown, at least a pair of substantially cylindrical portions obtained by dividing the substantially cylindrical shape in the circumferential direction instead of the substantially cylindrical shape are opposed to each other. It may be provided. For example, as shown in FIG. 12, the pressing portion is constituted by a pressing member 206 having a configuration in which a thin rectangular leaf spring is provided and the leaf spring is provided at a plurality of locations (for example, 6 locations) in the circumferential direction. It may be formed.
Further, as the pressing portion according to the embodiment, as shown in FIG. 13, as a pressing portion 406 in a form in which a portion protruding inwardly is formed by denting the wall surface of the core drill A itself toward the inner periphery. In such a case, as shown in FIG. 14, a plurality of (for example, three locations) may be provided in the circumferential direction.
Further, as a modified example of the core drill A shown in FIG. 1, as shown in FIG. 11, the concave portion 1B is arranged in the longitudinal direction (vertical direction in FIG. 11) of the inner peripheral surface 1F of the core drill A, as shown in FIG. It is good also as a structure provided in multiple places, and in such a case, according to the length (thickness of the punched object) of the cut-out scrap 9 (see FIG. 3), the pressing member (plate The spring 6 may be selectively disposed. However, when the mass of the cut-out scrap 9 is large or the spring force of the leaf spring is weak, the pressing member 6 made of a leaf spring is arranged in the recesses 1B at all locations or in the recesses 1B at a plurality of locations. May be. Thus, in the longitudinal direction of the core drill A, the structure in which the pressing portion or the pressing members (leaf springs, etc.) constituting the pressing portion are provided at a plurality of locations is the pressing portion having the form as shown in FIGS. Needless to say, this is also applicable.

However, in any case, as the pressing members 6, 106, 206, it is necessary that a part of the members constituting the pressing members 6, 106, 206 protrude from the inner peripheral surface 1F of the core drill A toward the inner diameter.
11 to 13, the main configuration of the core drill A is denoted by the same reference numerals as those of the core drill A shown in FIG.

Further, the pressing member according to another embodiment is not a single member but a plurality of members, for example, constituted by a pressing member and a biasing member that biases the member toward the inner diameter. There may be.

By the way, as a pressing member having a configuration different from the above-described configuration, in addition to the form using the leaf spring described above, as shown in FIGS. 5 and 6, the pressing member 306 having a form using a coil spring, Specifically, the winding diameter is reduced in at least part of the longitudinal direction and protrudes toward the inner diameter, that is, the maximum diameter portion 6m has a winding diameter equal to the inner peripheral diameter of the core body and is slightly wound. The pressing member 306 may be configured by a coil spring having a form in which at least one minimum diameter portion 6n having a reduced diameter is formed in a portion that is biased toward the center from both ends. It is desirable that each portion in the longitudinal direction is configured by a coil spring having a shape that is “wavy” as a whole by sequentially changing in the radial direction. 5 and FIG. 6, since the other configurations are the same, the same reference numerals are given to the same components as those in FIG. 1 to FIG. 3, and description thereof will be omitted.

Also, it is desirable that any of the pressing members described above is made of a metal having elasticity such as spring steel. However, other materials, for example, non-metal (specifically, resin, rubber, ceramic, etc.) may be used.

Thus, the core drill A configured as described above acts as follows when drilling a drilled object such as metal or concrete. That means
As shown in FIG. 3, when a hole is to be drilled in an object to be drilled B, for example, a steel frame of a bridge over a river, the core drill A can be used to drill a circular hole.

In this drilling process, as drilling progresses, a cylindrical cut-out scrap 9 is gradually formed inside the core body 1 of the core drill A. When the cut waste material 9 grows up to a position where it comes into contact with the pressing member 6 disposed on the inner peripheral surface 1F of the core body 1, the cut waste material 9 is moved from the periphery to the inner diameter side by the pressing member 6. It will be in an energized state. Then, as the drilling further proceeds and the through hole is finally drilled in the drilled object B as shown in FIG. 3, the cut-out scrap 9 inside the core body 1 is pressed by the pressing member 6 to the core body. 1 is engaged and held inside. Needless to say, this effect can be achieved even with other forms of the pressing portion 406 and the pressing members 106, 206, and 306 constituting the pressing portion.

For this reason, as shown in FIG. 4, even if the core drill A is pulled out from the hole H formed in the drilled object B, the cut-out scrap 9 does not fall out of the core drill A and is retained (held) ) Can be maintained.

Therefore, unlike the conventional case, there is no fear that the cut-out waste material 9 falls in the river below and affects the environment.

Then, the cut-out scrap 9 inside the core body 1 is inserted into the elongated hole 3 (see FIGS. 1 and 5) by inserting a tool having an inclined surface, such as a pressing pin (extrusion pin), or By inserting and pressing the back surface of the cut-out scrap 9 toward the distal end, the core body 1 can be discharged outward from the distal end. Then, if the discharged cutout waste material 9 is treated as a predetermined waste, the environment will not be polluted.

The above-described embodiments are merely examples of the present invention, and it goes without saying that the configurations and conditions may be changed as appropriate without departing from the technical idea of the present invention.

コ ア The core drill according to the present invention can be used for drilling various drilled objects at a construction site, a factory, or the like.

A ... Core drill 1 ... Core body 2 ... Cutting blade 4 ... Shank part 6,106,206,306,406 ... Pressing member (pressing part)

Claims (5)

In a core drill having a cylindrical core body, a cutting blade disposed at the lower end of the core body, and a shank portion disposed on the upper end surface of the core body and attached to the drilling device side,
A core drill characterized in that a pressing portion is provided on an inner peripheral surface of the core body so as to protrude inwardly in the radial direction of the core body and to be elastically deformed in the outer diameter direction so as to be deformable. The inner peripheral surface is formed with a concave portion in which the inner peripheral surface is recessed in the outer diameter direction at a position spaced from the distal end of the core body to the proximal end side, and at least a part of the pressing member serving as the pressing portion is formed in the concave portion. The core drill according to claim 1, wherein the core drill is arranged so as to protrude further toward the inner diameter side from the inner peripheral surface. 3. The core drill according to claim 2, wherein the pressing member is constituted by a cylindrical or partially cylindrical leaf spring. A coil spring having a configuration in which the pressing member is formed in a portion in which the maximum diameter portion of the winding diameter is equal to the inner peripheral diameter of the core body and the minimum diameter portion of the winding diameter is deviated from the tip to the center side. The core drill according to claim 2, wherein the core drill is configured as follows. An opening is provided in a part of the core body, and the cut waste material retained in the core body is pressed from the opening toward the distal end of the core body and discharged. 4. The core drill according to any one of items 4.

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