KR20150101365A - Excavating bit with expandable wings - Google Patents

Abstract

The present invention relates to an excavating bit with expandable wings expanded by compressed air, and more specifically, to an excavating bit forming a partial expanding hole on an inner wall of a foundation pile laying hole through reaming when the ground is excavated to form a laying hole in the pre-boring construction of a foundation pile. The excavation bit has expandable wings expanded to the outside of a bit main body through compressed air supplied to the ground and forms the expanding hole while a degree of unfolding of the expandable wings is gradually increased as the expandable wings gradually crush the laying hole through rotation of the bit main body, thereby facilitating pre-boring construction of the foundation pile and reducing the construction period. The excavating bit with the expandable wings comprises: the bit main body having a plurality of receiving parts arranged in a radial shape; a plurality of expandable wings coupled to the receiving parts through a vertical rotational shaft to rotate toward the outside of the bit main body and including a crushing protrusion protruding in the unfolding direction of the expandable wings to the outside; an expandable wing unfolding maintaining means embedded in the bit main body and injecting air to the inside surface of the expandable wings; a restoring means for restoring the unfolded expandable wings to the receiving parts; and a rotary drive means rotating the bit main body in the same direction as the unfolding direction of the expandable wings.

Description

[0001] EXCAVATING BIT WITH EXPANDABLE WINGS [0002] FIELD OF THE INVENTION [0003]

The present invention relates to an excavating bit having a wing extending into compressed air,

More particularly, the present invention relates to an excavating bit for partially expanding the inner wall of a foundation file buried hole by reaming when excavating a buried hole in the ground during pre-boring of a foundation file, And the wing blade is gradually broken by the rotation of the bit body so that the degree of spreading of the wing blade is gradually increased to form a wedge so that the ease of pre-boring construction of the foundation pile To a drilling bit having a wing that can shorten the time required for securing and constructing the drilling bit.

In the case where a building or structure is ordinarily raised, foundation work is performed to reinforce the ground in order to support the upper structure according to the condition of the ground or the load of the structure,

If the ground contacted with the structure has sufficient rigidity to support it, the foundation can be carried out directly on it. However, in case of the soft ground, the pile or ground To strengthen the ground, and then to carry out foundation work on it.

At this time, the files to be installed on the soft ground are classified into steel pipe files, PC files, PHC files according to their materials, and they are classified into a steel pipe file, a tubular type file, and an H-shaped steel pipe file depending on the form and use.

Also, if you are going to do basic reinforcement work in the middle of an existing building, or if you want to do basic reinforcement work for a narrow area where large excavation equipment is not available, you should use micro file of small diameter file.

These microfiles are inserted through punched holes with a certain diameter and length, and then filled with a filler such as concrete or grout material, thereby integrating the microfiles with the ground.

The above process is referred to as pre-boring process of the foundation pile. The supporting force of the micro pile (hereinafter referred to as the small pile foundation file) installed at this time, especially the tensile force applied from the structure, must be resisted only by the friction between the foundation and the concrete The slip phenomenon and the separation phenomenon occur at the interface between the ground and the concrete in the case of the soft ground.

As a technique for solving the above problems, Korean Patent Registration No. 10-1334393 (Nov. 23, 2013), entitled " Preboring Construction Method of Small Diameter Foundation Files, " filed by the applicant of the present invention,

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a semiconductor device according to a first embodiment of the present invention; FIG. 2 is a cross- (G) buried holes (1), excavation steps (a), spreading 5 forming steps (b), foundation piles 10 embedding steps (c) ) And curing (step (d)).

In the step (b) shown in FIG. 1A, the excavation bit of the present invention is shown in FIG. 1A as dedicated equipment for exclusive use of wastes after excavation of a buried hole (1). Is inserted into the buried hole and the widening 5 having a larger diameter than the buried hole is formed at a predetermined interval in the vertical direction by blowing and rotating the widening equipment.

This prior art dedicated equipment is called a digging bit, and as a conventional technique related to such digging bit, there is a digging bit structure that can be extended in the rock (Korean Patent Registration No. 10-1132704)

2, the prior art includes a housing bit 20 having an inclined groove (not shown) having an air passage 22, a slant surface 34 having a slope whose bottom surface has the same slope as the slant groove of the housing bit 34 And a hammer chuck 40 built in the housing bit for repeatedly drawing out the wing bit toward the outside of the housing bit.

The wing bit 30 is pressed by the hitting of the hammer chuck 40 in the vertical direction and is lifted from the inclined groove of the housing bit 20 to be outwardly protruded from the housing bit.

As the housing bit is rotated, the wing bit 30 is repeatedly pulled out from the housing bit 20, and the wringing bit and the rotational force are used to form the wing 5 (see FIG. 1).

However, it is difficult to form a hole in a precise size when forming a hole in a construction based on the registered patent of the applicant of the present invention by using the excavation equipment 3 as in the prior art, The durability of the excavation bit is weak, so that frequent failures and breakage occur during construction and the construction period is increased.

This is due to the fact that the wing bit 30 in the above-mentioned prior art forms a hole in the buried hole while rotating using the crushing energy.

That is, the pressure applied in the vertical direction is converted into the horizontal direction crushing energy of the wing bit by the sliding movement of the inclined groove and the inclined surface. Since the wing bit is formed by using the rotational force together with the repetitive hitting, The direction of the crushing energy acts in a direction perpendicular to each other, so that when the pressure of the hammer chuck is transmitted to the wing bit, the crushing energy is distributed in the horizontal direction and the counterforce in the vertical direction.

Therefore, the excavation bit according to the related art has a large loss of crushing energy compared to the pressure used, and therefore, it takes a long time for construction because of low efficiency of formation of holes, and excessive pressure is concentrated on the hammer chuck and wing bits, There is an easy problem.

Particularly, if the slant grooves of the hammer chuck or the slant face of the wing bit cause minute breakage, the sliding movement is interfered by the breakage, the wing bit forming efficiency of the wing bit is further lowered and the construction time is also increased. Since the housing bit is lowered when the wing bit is protruded to protrude to the outside when the wing bit is protruded from the inclined groove of the housing bit, the outer cross-sectional shape (in particular, the upper face of the wedge) Thus, there is a limitation in applying the bit of the above-mentioned prior art to the above-mentioned Japanese Patent No. 10-1334393 since it can not guarantee the function as a shear key using the overhead.

In addition, since the wing bit is protruded through the hitting of the hammer chuck and the wing bit, the noise generated by the wing bit is very large,

In addition, the above-mentioned prior art technique is to use a wing bit of a general diameter as a dedicated bit for drilling, to excavate the wing bit to a buried hole forming position, to replace the wing bit of the prior art with a wing bit, It is necessary to replace the bit every time according to the number of openings, so that there is a problem that construction is very troublesome.

Accordingly, the present invention has been made to solve the above-mentioned problems,

The bit body is rotated and the wing blade gradually expands while crushing the buried hole by using the compressed air so that the counter force, frictional force, and load applied to the components of the excavation bit are reduced, It is possible to prevent the wing blade from being folded into the bit body and to form the wedge as if scraping the inner wall of the wedge hole through the fracture projection of the wing blade so as to increase the bubble forming efficiency and shorten the entire construction time of the pre- And to provide an excavation bit that can be used.

The present invention also provides a wing blade unfolding and holding device having an air jet nozzle that is exposed to a receiving portion of a bit body so as to prevent the wing blade from being folded into the bit body by concentrating the compressed air on a part of the wing blade, And a wing having a receiving groove in which the air jet nozzle is received.

Furthermore, in order to prevent the excavation residues such as sand, soil, pebbles, and the like, which are generated in the buried holes in the hole forming operation, from interfering between the receiving portion and the drilled wing to cause failure or breakage of the drilling bit, And a drill bit having a plurality of slit grooves communicating with the receiving portion.

According to another aspect of the present invention, there is provided a wing blade for preventing the wing blade from being released to the outside of the bit body when the wing blade is unfolded, A stopper is provided at the end of the guide groove, a guide groove in which the stopper is guided on the contact surface of the accommodating portion with which the guide surface is in contact, and a stopper for hooking the stopper at the outer end of the guide groove.

In order to achieve the above-mentioned object, the excavating bit having the wing according to the present invention

A bit body having a plurality of receiving portions radially arranged;

A plurality of wing blades which are coupled through a vertical rotation shaft in the receiving portion and installed so as to spread out of the bit body, and have a crushing protrusion protruded in an outer spreading direction;

A wing spreader holding means embedded in the bit body for spraying air toward the inner side of the wing blade; And

Rotation driving means for rotating the bit body in the same direction as the unfolding direction of the wing blade;

And a control unit.

Further, in the excavating bit equipped with the wing according to the present invention,

And an external driving means for rotating a rotary shaft connected to the bit body.

In the excavating bit having the wing according to the present invention,

And an electric motor incorporated in the bit body for rotating the body portion in which the wing blade is received.

Further, in the excavating bit having the wing according to the present invention, the wing spreader holding means includes an air jetting nozzle exposed to the receiving portion,

And the air bladder includes a receiving groove on the inner side of which the air spray nozzle is accommodated and in which air injected therein stays.

 The excavating bit with the wing according to the present invention can reduce the noise at the construction site by forming the wing as if the bit body rotates and the wing blade gradually expands using the compressed air to scrape the inner wall of the buried hole In addition,

In particular, a wing blade which is axially coupled to a receiving portion of the bit body through a vertical rotation shaft and a wing-wing spreading-and-holding means for jetting air toward the inner side of the wing-

It is possible to uniformly and precisely form the widening of the wing blades because the repulsive force generated when the wing protrusion of the wing blade comes into contact with the inner wall of the buried hole is canceled and the spreading state of the wing blade is firmly maintained, The load such as the opposing force, the frictional force, and the resistance force applied to the parts is solved to improve the overall durability, thereby preventing the breakdown and damage.

Further, the excavating bit with a wing according to the present invention is a rotation driving means for rotating and driving the bit body, an external driving means for rotating the rotary shaft connected to the bit body, or a body built in the bit body, By adopting the electric motor, excavation bits of various specifications can be provided according to the size and depth of the buried hole, and therefore, it is excellent in versatility and utility.

Further, according to the present invention, the excavating bit equipped with the wing blade adopts the air injection nozzle accommodated in the receiving groove formed on the inner side of the wing blade, so that as the compressed air is concentrated on a part of the wing blade, So that the bubble forming operation can be carried out easily and quickly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view for explaining a construction method in which an excavating bit according to the present invention is used; FIG.
2 is a view for explaining a drilling rig according to the prior art;
FIG. 3 is a perspective view and a main part perspective view showing an operating state of an excavating bit according to the present invention; FIG.
4 is a cross-sectional view schematically illustrating an excavation bit according to the present invention.
5 is an exploded perspective view of an excavating bit according to the present invention.
Figs. 6 and 7 are cross-sectional views, respectively, showing an operating state of an excavating bit according to the present invention; Fig.

While the present invention has been described in connection with certain embodiments, it is obvious that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

In the drawings, the same reference numerals are used for the same reference numerals, and in particular, the numerals of the tens and the digits of the digits, the digits of the tens, the digits of the digits and the alphabets are the same, Members referred to by reference numerals can be identified as members corresponding to these standards.

In the drawings, the components are expressed by exaggeratingly larger (or thicker) or smaller (or thinner) in size or thickness in consideration of the convenience of understanding, etc. However, It should not be.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.

 In the present application, the term " comprising " or " consisting of ", or the like, refers to the presence of a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

It is to be understood that the first to second aspects described in the present specification are merely referred to in order to distinguish between different components and are not limited to the order in which they are manufactured, It may not match.

In describing the excavation bit according to the present invention, when it is specified for the sake of convenience, the rough direction reference is made with reference to FIG. 3 to FIG. 5, the upward, downward, leftward and rightward directions are determined as the direction in which the gravitational force is applied.

In particular, in FIG. 3, the direction in which the wing blade 20 is deployed in the receiving portion 13 is set to the outside with the center of the bit body 10 inward, and the inner and outer sides Unless otherwise specified in the Detailed Description of the Invention and the Claims relating to the different drawings.

As described above, the reference numerals of Figs. 1 and 2, which are the same as those of Figs. 3 to 7, are independent of each other.

In the present specification, the open-pit excavation construction will be described on the basis of the "pre-boring construction method of the small-diameter foundation file" of the applicant's registered patent No. 10-1334393 (November 23, 2013) It is needless to say that the present invention is applied to various construction methods requiring preforming such as preboring construction of a large diameter foundation file.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a drilling bit with a wing according to the present invention will be described with reference to the accompanying drawings.

3 to 7, a drilling bit with a wing according to the present invention comprises a bit body 10, a plurality of wing blades housed in the bit body 10 and extending outwardly, (20), a unfolding holding means (30) for unfolding the wing blade (20), and a returning means (40).

3 to 5, the bit body 10 is a cylindrical member which is inserted into a buried hole 1 drilled in the ground to form a hole having a diameter larger than that of the buried hole 1 at a predetermined height .

The bit body 10 includes a body 11 having a wing 20 at its lower portion and a shaft connecting portion 12 connected to an upper portion of the body 11.

Although not shown in the drawing, the shaft connecting portion 12 is coupled to a rotating shaft connected to the external driving means, so that the bit body is embedded in the ground from the ground, and can rotate in one direction at the opening forming height.

3 to 5, the shaft connecting portion 12 is provided with an air supply passage 31 penetrating along the longitudinal direction, and the air supply passage 31 is connected to the ground compressed air injection means (See FIG. 5) provided in the body portion 11 and connected to the air blowing unit (not shown).

In addition, the bit body 10 may further include a rotation driving means using an electric motor mounted on a bit body, not an external driving means (to be described later) And the like, and the like.

The body portion 11 is provided with a plurality of receiving portions 13 radially accommodating the wings 20 on the basis of a central portion to which the air supply passage 31 is connected. The number of the wings may vary depending on the diameter of the wing, and in this specification, three wings 13 and wings 20 are shown in a representative form.

The receiving portions 13 (the wing blades 20) are disposed at the same angle with respect to the air supply passage 31 so that the bit body rotates to form a wing extending from the wing wing, And the like.

Therefore, in the case of performing the pre-boring work according to the registered patent No. 10-1334393, the buried hole is excavated to a predetermined depth up to a design depth by using general bits, and then replaced with a drilled bit according to the present invention. Or the lowest position), and then form the wedge. Then, sequentially move the wedge bit from the upper portion to the lower portion (or the lower portion to the upper portion) to the additional wedge position by design, And excavated.

That is, in the case of the bite bit according to the prior art shown in FIG. 2, if the wing bit having the general diameter is used to excavate the buried hole, when the bite hole reaches the bite forming position, Therefore, since the number of wing bit replacement increases as the number of wing holes increases, it is very troublesome and requires a long time for construction. Since the wing bit is gradually formed while descending and rotating with the hammer chuck striking, (The upper surface of the wing, that is, the surface extending from the buried hole to the outermost side of the wedge) is inclined downward as it goes outward, and the lower surface of the wedge is also inclined downward The function as a shear key for improving the supporting force of the foundation pile can not be guaranteed,

In the present invention, the buried holes are firstly excavated to the basic design depth by using general bits, and then the buried bits are inserted in the state where the buried bits are replaced with the buried bits of the present invention. Since it is possible to sequentially form the wedge after moving the wedge bit for each forming position, it is possible to perform the construction in a state in which the wedge bit is replaced only once irrespective of the number of the wedge. Therefore, the construction time is remarkably shortened In addition,

Since the wing blade of the present invention spreads in the horizontal direction and forms a wedge, the upper and lower surfaces of the wedge are formed in a right angle with the buried hole, so that it is possible to more reliably realize the function as a shear key for supporting force of the foundation pile.

3 to 5, the wing blade 20 accommodated in the receiving portion 13 of the bit body 10 is axially coupled to the bit body 10 at one side thereof, And is unfolded toward the outside of the bit body 10 by the means 30.

3, the wing blade 20 is vertically received in the receiving portion 13 in the rotating direction in consideration of the rotating direction of the bit body 10 (clockwise direction in FIG. 3), as shown in the left- It is preferable to be coupled through the pivot shaft 21 to be engaged.

The wing blade 20 is composed of a light weight portion 20A fixed on the rotation axis 21 and a weight portion 20B twisted by a fracture surface to be rotated. When the wing blade 20 rotates about the rotation axis 21 It is preferable that the weight of the weight portion 20B is tilted outwardly by the centrifugal force to improve the fracture energy,

Accordingly, the wing blade 20 has a planar shape of a pseudo isosceles triangle shape having the pivot 21 as an upper corner.

5, the outer circumferential surface of the outer circumferential surface of the wing blade 20 which contacts the inside of the accommodating portion 13 is referred to as an inner surface 20a and a weight portion 20B, The outer circumferential surface constituting the bit body 10 is exposed to the outside of the bit body 10 and contacts the inner wall of the buried hole 1 at the time of rotation so as to divide the outer circumferential surface which forms the hole by scraping into the broken surface 20c,

A portion of the inner peripheral surface of the receiving portion 13 where the inner side surface 20a of the wing blade 20 contacts the inner surface 13a of the receiving portion 13 and a portion of the inner surface 13b of the receiving portion 13, It is also referred to as top and bottom.

The crushing surface 20c is provided with a plurality of crushing protrusions 23 protruding outwardly so that the wing blade 20 is moved outwardly of the bit body 10 by the wing- And is crushed as if scraping the inner wall of the buried hole 1 to form the boss 5.

A plurality of the crushing protrusions 23 may be arranged over the entire crushing surface 20c and the crushing protrusions 23 may be arranged in the vertical direction in the connecting portion, Or more are more preferable in view of the efficiency of crushing the inner wall of the buried hole 1, and it can be confirmed that the crushing protrusions are arranged in a row or in two rows in the left side perspective views of FIG.

4, when the crushing protrusions are arranged in two rows in the vertical direction, the crushing protrusions of the respective rows are preferably arranged so as to intersect with each other. Therefore, And the crushing protrusions of the second row (inner side) are in contact with each other.

At this time, the pivot 21 of the piercing blade 20 may be integrally formed with the lightweight portion 20A of the piercing blade 20, but the piercing blade 20 and other configurations of the piercing blade 20 may be replaced, It is more preferable that a separate rotary shaft 21 is axially coupled to the receiving portion 13 of the bit body 10 while passing through the light weight portion 20A of the wing blade 20 so that the separation can be easily performed.

The light weight portion 20A of the wing blade 20 is provided with a shaft hole 22 penetrating in the vertical direction and the upper and lower surfaces of the receiving portion 13 of the bit body are provided on the wing blade 20, And a shaft coupling portion 14 to which the pivot shaft 21 is inserted and axially coupled.

At this time, the shaft coupling portion 14 has a shaft coupling hole 14A in which the upper end portion of the rotary shaft 21 is inserted into the upper surface of the receiving portion 13, And an axial coupling hole 14B that vertically passes through the shaft hole 14B.

A threaded portion (not shown) is provided on the inner peripheral surface of the shaft engagement hole 14B and a corresponding threaded portion 21a is provided on the outer peripheral surface of the head portion 21b of the rotary shaft 21, (For example, a bolt shape, a hexagonal nut shape, a groove for a hexagonal wrench, etc.).

The pivot shaft 21 is inserted into the shaft coupling hole 14A through the shaft coupling hole 14B while the wing blade 20 is accommodated in the receiving portion 13, It is possible to facilitate the engagement between the wing blade 20 and the bit body 10 by fixing the wing blade 20 to the screw body 11 by screwing.

In addition, when the wing blade 20 is separated due to the necessity of replacing other parts including the wing blade 20, the wing blade 20 is separated by releasing the rotating shaft 21, It is possible to facilitate maintenance and repair of the excavating bit in association with the detachment structure of the elastic body as the returning means 40.

4, the open wing spreading and holding means 30 of the present invention includes an air supply passage 31 formed in the longitudinal direction of the bit body 10 and connected to ground compressed air supply means (not shown) .

The air supply path 31 may be provided as a separate air supply pipe, or when the external driving means is introduced, the hollow inside the rotation shaft may serve as an air supply path, and the rotation shaft may function as the air supply pipe 33.

The air supply passage 31 is connected to an air injection portion communicating with the accommodating portions 13 radially arranged on the body 11. The air injection portion is formed on the inner side 13a of the accommodating portion 13 Air is blown toward the inner side surface 20a of the wing blade 20 so that the compressed air vertically lowered through the air supply path 31 is directed in the extending direction of the wing blade 20, 10) so that the outward direction and the compressed air injection direction of the injection portion are formed to be the same.

At this time, the open-air spreading and holding means 30 of the open-air spreading unit 30 is formed as a jetting portion so as to extend outwardly from the inner surface 13a of the accommodating portion 13, that is, (See FIG. 5)

A nozzle tube 32a connected to the air supply passage and vertically disposed in the accommodating portion and a nozzle tube 32b connected to the nozzle tube and extending outward in the direction of the inner surface 13a of the accommodating portion 13, And an air injection nozzle 32 (see FIG. 6) composed of a horizontally outwardly protruding nozzle portion 32b perpendicular to the nozzles 32a, 32a,

The wing blade 20 has an inner side surface 20a formed with a receiving groove 24 in which the air jet nozzle 32 is received.

Therefore, as shown in [A] of FIG. 6, the air injection nozzle 32 is also received (inserted) in the receiving groove 24 in a state where the wing blade 20 is received in the receiving portion 13, 6, compressed air is supplied from the compressed air to the receiving groove 24 through the air injection nozzle 32. As a result, when the compressed air is supplied from the ground, as shown in [B] and [C] So that the repulsive force generated when the wing blade 20 comes into contact with the inner wall of the buried hole can be canceled. As a result, the wing blade gradually expands by the expanded diameter by the expansion of the inner wall of the buried hole So that the required diameter is formed.

In addition, since the injection direction of the compressed air is concentrated and injected in the same direction as the spreading direction of the wing blade 20, only a part of the compressed air staying on the receiving groove 24 is discharged to the outside ) The pressure of the compressed air is kept constant at a high pressure, so that it is possible to quickly form an accurate shape.

In addition, since the outer cross-sectional shape of the bore hole is excavated in a vertical form, since the wing is formed in the unfolded state, the preforming of the foundation file according to the applicant's patent No. 10-1334393 The function as a shear key for increasing the supporting force of the foundation pile can be assured more reliably while the concrete is cured at the formed site.

Since the wing blade 20 has a predetermined height in the vertical direction, the injection nozzle 32 and the receiving groove 24 may also have a predetermined length in the vertical direction (see FIG. 4)

Or nozzle parts 32b protruding outwardly from the nozzle tube 32a having a predetermined length in the vertical direction may be spaced apart at a predetermined interval.

The present invention is not limited to the external driving means but may be a rotation driving means of the bit body 10 so as to rotate the body portion 11 to the shaft connecting portion 12 of the bit body 10, An electric motor M may be incorporated.

The bit body 10 is fixedly coupled to the lower portion of the air supply pipe 33 provided with the air supply path 31 and the air branch path 17A communicated with the air supply path 31 is radially arranged The fixed powder 17,

An electric motor M having a drive shaft M 1 fixedly connected to the lower portion of the stationary powder 17 and having an air conveying path 18B communicating with the air branching path 17A along the electric motor M, , A motor housing (18)

The electric motor M is rotatably coupled to the motor housing between the motor housing 18 and the body 11 and is fixedly coupled to the body so that the body 11 and / And a rotating powder body 19 having an air compression path 19A communicated with the air conveyance path 18B and rotated together.

Therefore, the fixed powder 17, the motor housing 18, and the rotating powder body 19 function as the above-described shaft connecting portion 12, and the body portion 11 is rotated by the electric motor M do.

More specifically, first, the fixed powder 17 is divided into a plurality of (three in the figure) air branch paths 17A formed in the vertical direction so as to communicate with the air supply path 31, Each of the air flow paths 17A has a narrow width portion 17a connected to the air supply path 31 and a narrow width portion 17a extending downward from the narrow width portion 17a, And a wide portion 17b inclined toward the outer circumferential surface of the stationary powder 17 and widening the width of the air branch passage 17A. .

The motor housing 18 is provided with an air conveying path 18B along the periphery of the mounting portion on which the electric motor M is mounted,

The rotating powder body 19 has an upper end rotatably coupled to the motor housing 18 and a lower end fixedly coupled to the body 11. The driving shaft M1 of the electric motor M is coupled to the center of the rotating powder body 19, Is provided in the vertical direction.

A plurality of (three in the figure) air compressing passages 19A are radially arranged along the circumference of the shaft hole. Each of the air compressing passages 19A is connected to the air conveying path 18B And a narrow width portion 19b which is inclined toward the inside of the rotary powder body 19 and goes downward from the wide portion 19a to narrow the width of the air compression passage 19A, And the air compressing passages 19A are arranged in a shape similar to the reverse conical shape on the vertical plane with respect to the center of the rotary powder body 19. [

The narrow portion 19b of the air compression passages 19A is connected to the nozzle pipe 32a of the air injection nozzle 32 and is expanded through the air passage 17A and the air transfer passage 18B The compressed air is compressed again through the narrow portion 19b of the air compression passages 19A and finally discharged and injected into the nozzle portion 32b through the nozzle pipe 32a.

Therefore, when the compressed air is supplied onto the air supply path 31 after driving the electric motor M to form the bore,

The compressed air is first introduced into the air conveyance route 18B via the air branch passage 17A and the compressed air passing through the air conveyance route 18B is compressed while the width of the air compressing passage 19A is narrowed, 11 to the inner surface of the wing blade 20 through the nozzle portion 32b via the nozzle tube 32a,

At the same time, the combined body of the rotating powder body 19 and the body portion 11 is rotated by the electric motor M,

As a result, the centrifugal force is added to the pressure of the compressed air that causes the wing blade 20 to unfold, so that the inner wall of the buried hole is broken and the expansion is gradually formed.

In this case, since the rotating powder body 19 rotates in a state where the air compressor 19A is disconnected, the air conveying path 18B is preferably provided in a donut shape.

The body 11 includes an extension 11A having an air outlet hole 11a formed along the outer circumference at a lower portion thereof and an opening 11A screwed to the extension 11A to open and close the air outlet hole 11a, Member 11B.

The degree of opening and closing of the air discharge hole 11a through the opening and closing member 11B may be controlled to adjust the amount of the compressed air discharged to adjust the pressure to unfold the wing 20.

That is, a part of the compressed air is discharged to the outside by the slit groove 25 described later,

When the ground forming the opening is hard, the amount of the compressed air to be supplied is excessively larger than the extent to which the wing blade 20 is deployed (i.e., the volume of the internal space on the accommodating portion 13 where the compressed air can stay) There is a possibility that backflow of the compressed air or overload of the compressed air supply means may occur,

In the case where the ground is soft, the pressure of the compressed air is too high, so that the wing blade 20 may not be gradually deployed, but may be unfolded at once,

The pressure of the compressed air staying on the accommodating portion 13 is adjusted by adjusting the amount of compressed air discharged through the opening and closing member 11B.

The cap 32c is connected to the lower portion of the nozzle tube 32a by an elastic body so that the cap 32c is opened only when the compressed air is supplied to discharge a portion of the compressed air into the air discharge hole 11a. can do.

6 and 7, according to the present invention, when the supply of the compressed air is stopped after the formation of the blanks is completed, the return means 40 (see FIG. 6) for automatically returning the wing blade 20 to the receiving portion 13 ).

The returning means 40 is constituted by an elastic body 41 which connects the inner side surface 13a of the accommodating portion 13 and the inner side surface 20a of the wing blade 20 and exerts an elastic force so that both ends are contracted.

Therefore, when the wing blade 20 is completely opened by the compressed air and the formation of the widening is completed and supply of the compressed air is stopped, the wing blade 20 is automatically moved to the receiving portion 13 by the elastic force of the elastic body 41 Return.

It is preferable that the elastic body 41 is provided at a position as close as possible to the weight portion 20B of the wing blade 20 or at a position adjacent to the receiving groove 24 in order to facilitate returning of the wing blade 20 desirable.

In order to secure the ease of fastening of the elastic body 41 and to secure the ease of separation of the excavating bit,

The wing blade 20 is provided with a through hole 26 penetrating the left and right transverse direction to insert the elastic body 41,

The elastic body 41 includes an elastic portion 41a that is located on the through hole 26 and exerts an elastic force and an elastic portion 41b that is connected to one side of the elastic portion 41a and is provided on an outer peripheral surface of the through hole 26 And is connected to the other side of the elastic portion 41a. The head portion 41b is screw-connected to the screw portion 26a and is in a form in which a tool can be used (representatively, a bolt type in which a driver is usable) And a tail portion 41c screwed to the fastening hole 16 provided on the inner side surface 13a of the receiving portion 13. [

The elastic member 41 is inserted through the through hole 26 in a state where the wing blade 20 is coupled to the receiving portion 13 When the head portion 41b is tightened with a tool, the head portion 41b and the tail portion 41c are simultaneously engaged with the through-holes 26 and the angles of the fastening holes 16 And screwed into the threaded portions 26a and 16a.

When the wing blade 20 is dismounted from the bit body 10, the wing blade 20 can be separated only by releasing the elastic body 41 and the rotating shaft 21 (in the order of no matter) It is possible to separate and replace only the elastic body 41 without the necessity of separating the wing blade 20 when it is necessary to replace the elastic body 41 due to damage such as reduction in the elastic force of the elastic body 41, .

Meanwhile, the length of the elastic body 41 increases as the wing blade 20 is deployed. At this time, since the trajectory of the weight of the wing blade is circular, the elastic portion 41a of the elastic body contacts the inner peripheral surface of the through- There is room for damage.

6, the inside of the through hole 26 is formed with a cutout portion 26b for preventing the length and shape displacement of the elastic portion 26 from being interfered with the spreading trajectory of the wing blade 20, .

As the diameter of the widening blade 20 becomes larger, the expansion length of the elastic body 41 becomes longer as the diameter of the widening blade 20 becomes larger. Therefore, interference between the wing blade 20 and the elastic body 41 through the cut- , There is a limitation in preventing contact.

Thus, the present invention can facilitate separation and coupling of the elastic body by introducing the deformed elastic body (42).

7, the deformed elastic body 42 is a head part, which corresponds to the length of the through hole 26 of the wing blade 20 and is inserted into and screwed into the through hole, (42b).

Therefore, when the elastic body 42 is coupled to both the wing blade 20 and the receiving portion 13, one end of the elastic portion 42a is positioned on the inner surface of the through hole rather than the outer surface of the through hole 26 So that it is possible to more easily perform the separation and bonding operation through the bolt portion.

4 to 7, a plurality of slit grooves 25 communicating with the accommodating portion 13 are formed on all or a part of the outer circumferential surface of the wing blade 20 so as to be recessed in the unfolding direction .

6 and 7, when the air is exhausted by the injection nozzle 32 in a state where the wing blade 20 is completely housed in the receiving portion 13 as shown in [A] of Figs. 6 and 7, The wing blade 20 is unfolded and the air discharged to the receiving portion 13 is cooled and a part of the compressed air is discharged into the slit grooves 25 communicating with the receiving portion 13 .

That is, as the wing blade 20 is rotated and unfolded, the inner wall of the buried hole 1 is broken between gaps (fine gaps) formed between the wing blade 20 and the inner peripheral surface of the receiving portion 13, Sand, soil, stone, etc.) may be interfered with and interfere with the rotation of the wing blade 20 and may act as a factor to cause breakage,

The compressed air is discharged through the slit grooves 25, and the compressed air leaks through the gaps to remove the residues sandwiched between the gaps. Thus, the above problems can be prevented in advance.

This is because the pressure for discharging the compressed air into the gap between the wing blade 20 and the receiving portion 13 is limited when the slit groove 25 is not provided, so that the effect of removing the residue can not be expected.

The compressed air discharged through the slit grooves 25 assists the crushing effect of the inner wall of the buried hole 1 by the compressed air, and dust generated by the crushed dust is buried in the buried hole 1 by the compressed air, And has an effect of being discharged.

The present invention further includes limiting means for limiting the turning radius of the wing (20).

6 and 7, a stopper 27 protruding from the inner end of the guide surface 20b of the wing blade 20 is provided as the limiting means of the present invention,

A guide groove 15 in which the stopper 27 is guided is formed on the contact surface 13b of the accommodating portion 13 in contact with the guide surface 20b of the wing blade 20 along the direction of unfolding, (15a) to which the stopper (27) is caught is provided at an outer end portion of the stopper (15).

The length of the guide groove 15, that is, the length between the engagement protrusion 15a and the inner end of the contact surface 13b will be formed to correspond to the diameter of the bore to be formed, The stopper 27 is caught by the stopping protrusion 15a to limit the turning radius of the wing 20 so that even when the air is continuously sprayed on the wing 20, The weight portion 20B of the receiving portion 13 can be prevented from being completely separated from the receiving portion 13. [

In addition, if the size of the stopper is different from that of the stopper, the contact position between the stopper and the stopper is changed, so that the turning radius of the wing can be adjusted.

At this time, the stopper 27 has a width and a projection width of a predetermined thickness or more (for example, about 1/7 to 1/5 of the thickness of the guide surface 20b), and the stopper 27 and the engagement protrusions 15a To prevent breakage due to contact shock,

Further, the stopper 27, the guide groove 15 and the engagement step 15a are disposed in multiple rows in the direction perpendicular to the guide surface 20b and the contact surface 13b, respectively, so that the stopper 27 and the engagement step 15a are damaged So that it is possible to complement (reinforce) the fact that the rotation limiting function of the wing blade 20 is lost.

Therefore, according to the present invention, since the wing blade is gradually expanded by using the compressed air pressure, the wing is rotated about the inner wall of the buried hole to increase the efficiency of wringing, Friction, and resistance against the drive pressure, such as a bit, does not occur. Therefore, the pressure load applied to each component is not generated, thereby improving the durability and preventing the failure or damage of the excavation bit.

Although the description of the structures of the present invention, particularly the materials of the breakage projections 23 to the stoppers 27 and the like, is omitted here, it is made of a material with durability that can prevent breakage due to the characteristics of excavating bits. Do.

While the present invention has been described with reference to the accompanying drawings, it is to be understood that the present invention is not limited to the disclosed embodiments, but various modifications, alterations, and substitutions can be made by those skilled in the art, Changes and substitutions are to be construed as falling within the scope of protection of the present invention.

10: bit body 11: body part
12: shaft connecting portion 13: receiving portion
14: shaft coupling portion 15: guide groove
16: fastening hole
20: wing blade 21:
22: shaft hole 23: crushing projection
24: receiving groove 25: slit groove
26: Through hole 27: Stopper
30: open wing spreading maintenance means 31: air supply path
32: injection nozzle
40: return means 41, 42: elastic body

Claims (4)

A bit body having a plurality of receiving portions radially arranged;
A plurality of wing blades which are coupled through a vertical rotation shaft in the receiving portion and installed so as to be spread out of the bit body and have a crushing protrusion protruding in an outer spreading direction;
A wing spreader holding means embedded in the bit body for spraying air toward the inner side of the wing blade; And
Rotation driving means for rotating the bit body in the same direction as the unfolding direction of the wing blade;
Wherein the drill bit has a plurality of drill bits. The method according to claim 1,
The rotation drive means
And an external drive means for rotating a rotary shaft connected to the bit body. The method according to claim 1,
The rotation drive means
And an electric motor built in the bit body for rotating the body portion in which the wing blade is housed. 4. The method according to any one of claims 1 to 3,
Wherein the open-air spreading and holding means includes an air injection nozzle exposed to the accommodation portion,
Wherein the wing blade includes an accommodating groove in which the air injected while the air injection nozzle is accommodated is retained on an inner surface thereof.

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