JP3325249B2 - Perforated casing for civil engineering - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilled casing for civil engineering work, and is widely applicable to the field of use of casings in civil engineering foundation works such as an all-casing method, pile driving, and pile removal. .

[0002]

2. Description of the Related Art A casing method in which a pile is used together with an auger for pile driving or pile removal has been used frequently. For example, a casing called a double auger cuts only the circumference, and the auger has a cylindrical shape inside. In the construction method, the excavation proceeds with the bit at the tip, but the frictional resistance due to the surface contact between the casing and the ground is large, and large energy is used by large power using a large machine.

[0003] In the large-diameter casing method,
Using a high-power casing rotating machine, the casing is excavated while turning the casing back and forth. In the case of a leaderless pile driver (small machine), drilling of the casing prior to drilling the auger, drilling of the auger inside the casing, and piled the casing without soiling without vibration Have been.

[0004]

In any case, the drilling of the casing receives a frictional energy load much larger than the drilling energy at the tip depending on the soil due to a large frictional resistance between the outer and inner circumferences of the casing. Therefore, the casing method has a problem in that large power consumption is required. The present invention provides a novel casing
This makes it possible to drill the casing with relatively small power.

[0005]

For example, as shown in FIG. 1, a screw blade 4 is wound around an outer periphery of a steel pipe 10 and mounted thereon, as shown in FIG.
Supply pipe P ₂ along the lower surface base of screw blade 4
While attached to the upper end of the feed pipe P ₂ communicates with the fluid supply side, the high and attaching a lower drilling portion of the head 3 tip
It communicated with the nozzle N for pressure fluid injection . Therefore, during excavation, the screw blades 4 perform not only the excavation progress guide but also the excavation and excavation of the excavated soil, much like a blade with an auger screw, thereby significantly reducing the frictional resistance of the casing 1 against the ground. did. Moreover, the high pressure fluid (air, water) from the nozzle N during drilling through a feed pipe P ₂ because ejecting together to prevent cutting capability lowering of the head, rising discharge flow of the jet fluid is a circumferential surface of the casing 1 Reduce frictional resistance.

[0006] Then, since the supply pipe P ₂ is attached to the lower surface base of the screw blade 4, during drilling operations in the casing 1, the upper surface of the screw blade 4 functions as a discharge surface lifting excavation soil, feed pipe P ₂ is possible to prevent damage without receiving the frictional force between the excavated soil, yet does not also inhibit the guiding function of the screw blade.

A cap 2 is removably fitted to the upper end of the steel pipe 10, and a sealed chamber R is provided on the inner upper surface of the cap 2 through a connecting portion J to communicate with a fluid supply source. communicating the supply pipe P ₂ upper via coupler K and. Accordingly, since it is supplied to the supply pipe P ₂ and the nozzle N is also through the sealed chamber R high pressure fluid, the supply of constantly uniform pressure flow to the nozzle N is possible, the machine body M ₀ of drilling the casing 1 and attachment and detachment of the swivel part M ₂ also reasonably be achieved.

Further, a plurality of steel pipes 10 were connected by connecting the screw blades 4 and the supply pipe P ₂ in a communicating state. Therefore, it is possible to appropriately add a part during the construction according to the excavation depth, and even a small machine such as a leaderless machine can make a large depth drilling.

A connecting tube 11 is fitted to the lower end of the steel pipe 10.
Fix and fix the upper end of the other steel pipe 10 into the connection cylinder 11
Then, the steel pipe 10 was detachably added. Follow
And a connecting cylinder 11 at the lower end, and a screw blade 4
And supply pipe P _TwoA steel pipe 10 of appropriate length with
If multiple pieces are prepared, the required depth
Drilling can be performed freely, and each unit steel pipe can be added
In addition to being easy to separate, the casing 1
Transport and maintenance management are also facilitated.

[0010] Further, as a replenishing structure of the steel pipe 10, an engaging piece 13 having a width W ₀ and a height H ₁ which is substantially the same as the thickness of the connecting tube 11 is attached to the outer periphery of the upper part of the lower steel pipe 10. An incision O _{1 in} the connecting cylinder 11 at the lower end of the upper steel pipe 10 guides the locking piece 13 upward from the lower end and allows the lateral movement to be continued.
The provided with, the incision section O ₁ surface position to be placed and fixed to cover 12, the incision O the fitting plate 14 in the moved state locking piece 13 of the lower steel pipe 10 in the incision O ₁ laterally Dropped into _one .

Therefore, the refilling work of the steel pipe 10 is performed by fitting the connection pipe 11 at the lower end of the steel pipe 10 to the locking piece 13 on the upper part of the steel pipe 10 excavated and settled in the soil, and slightly rotating the fitting pipe 14. since the only on drop during incision O _1, is a simple and easy task, drawing after drilling work end of drilling the casing 1 also steel pipe 10 replenishment point comes into the ground
It is easy to repeat the work of sequentially removing
Deep drilling work can be easily performed even with a small leaderless machine with a maximum lifting length.

Furthermore, connecting tube 11 to the screw blade 4 each end of the lower and fitted steel pipe 10 the upper juxtaposed auxiliary blades 41 and 42 so as to sandwich the feed pipe P ₂ ends, the steel pipe 10 the upper end of the connecting cylinder 11 and to connect between the supply pipe P ₂ lower on the connecting tube 11 and the supply pipe P ₂ the upper end of the fitting steel pipe 10 in the connecting pipe C during fitting locking to. Therefore, the removal works of the replenishing work and single steel pipe cross, through the attachment and detachment of the connecting pipe C can conveniently performed without adversely affecting the supply pipe P _2, moreover connection of the feed pipe P ₂ are screw Since it is protected by the blade 4 and the auxiliary blades 41 and 42 in the sandwiching mode, damage during drilling work of the connecting pipe C is also minimized.

Since the cap 2 and the steel pipe 10, the steel pipe 10 and the steel pipe 10, and the steel pipe 10 and the head 3 are attached and detached by the same connecting means, the casing can be easily extended and separated, and the cap, the steel pipe, the head, etc. It can be rationalized from both the work of attaching and detaching means to each member and the maintenance.

The connecting pipe C is flexible and has couplers K at both ends. Thus, connecting and disconnecting operations of the feed pipe P ₂ after replenishing the steel pipe 10 is only attached to and detached from the respective connection ports P ₀ of the supply pipe P ₂ ends of each side of the coupler K at both ends of the connecting pipe C, coupling Since the pipe C is flexible, it is a simple manual operation.

The nozzle N has a structure in which a screw base S of a check valve is detachably provided at the tip. Therefore, when the work is stopped underground, earth pressure or water pressure acts on the nozzle N, and the tip of the nozzle is liable to be worn out. Maintenance becomes easier.

Further, inherent balls B of the nozzle N for closing the nozzle N, the screw cap S to the tip of the nozzle N by interposing the coil spring S _P between the proximal end of the ball B and the screw cap S Screwed. Therefore, although the supply pipe P ₂ is between the nozzle N is at rest at normal pressure ball B is closed the hole O ₅ of the nozzle N by the pressing force of the coil spring S _P, at the time of nozzle startup jetting high pressure fluid blowing the ball B, and pushes the coil spring S _P to the screw cap S side,
Ball B is to compress the coil spring S _P inside the tip of the screw cap S, direct impingement of the screw cap S of the ball B is avoided, wear of the ball B is minimized. Moreover, to close the hole O ₅ of ball B nozzles N prior to infiltration of sediment from the injection hole O ₄ screws mouthpiece S during nozzle rest, sediment from entering the nozzle N is also avoided, nozzle clogging even nozzle N Internal wear can be prevented.

Further, since the injection direction (line FF) of the nozzle N is set slightly inward of the head 3 in the direction of extension of the steel pipe 10 (line AA), during drilling of the casing 1, the injection direction from the nozzle N is reduced. The ejected high-pressure flow (air or water) not only assists the excavating action of the cutting blade, but the discharged fluid generates an ascending flow not only on the outer periphery but also on the inner periphery of the steel pipe 10, and the friction of the inner wall surface of the steel pipe 10 is increased. The casing during drilling can significantly reduce the frictional resistance with earth and sand in the ground due to the synergistic effect of the existence of the screw blades 4 on the outer circumference and the discharge fluid rising along the outer circumference and the inner circumference. .

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention was embodied as a drilling casing for a leaderless auger machine for drilling a pile with a 500 mm diameter auger screw. [Casting Structure] As shown in FIG. 1, a drilled casing 1 is formed by detachably connecting a head 3 at an end, an intermediate steel pipe 10 and a cap 2 at an upper end thereof in a detachable manner. feed pipe P ₂ for the screw blade 4 and the high pressure fluid of the outer peripheral surface of the casing 1 (mainly high pressure air) is one which is connected to the communicating state.

[Steel Pipe 10 (FIGS. 2 and 3)] Outer circumference d ₁ is 6
00 mm, wall thickness 10 mm, length L ₁ is 7 m, the lower end of the steel pipe body is 600 mm in inner diameter, wall thickness 15 mm, length L ₃ is 60
A steel connection tube 11 of 0 mm was fitted with an overlap width W (100 mm), and both were welded and fixed at an overlap width W. As shown in FIG. 3, the connecting cylinder 11 has a vertical notch having a width W ₁ (100 + α mm) from the lower end E ₃ to the center and a height H ₂ (150 + α mm) having a width W ₁ from the middle to the side. forming an incision O ₁ consisting of side notches, welded from the lower end of the incision O ₁ the cover 12 of the iron plate of thick 5mm to cover up the side notch in the connecting tube 11 surface incision O ₁ Reinforced.

On the outer periphery of the steel pipe 10, the fitting portion L ₄ (500 mm) at the upper end is left until the lower end of the connecting cylinder 11 is removed.
A 10 mm thick, 50 mm wide steel strip in an upright position and 6
The screw blade 4 is formed by winding and welding at a pitch of 00 mm and an inclination angle of 30 °, and a metal pipe having an inner diameter of 12 mm is attached to the base of the lower surface of the screw blade 4 by welding and supplied.
₂ is formed, the upper and lower ends of the screw blade 4 to protect the coupling port P ₀ of the upper and lower ends of the supply pipe P ₂ by collateral auxiliary blades 42 and 41.

The width W ₀ is 100 mm and the height H ₁ is 150 m in the middle of the fitting portion L _{4 on} the outer periphery of the upper end of the steel pipe 10.
An iron plate having a thickness of 12 mm was fixed by welding to form a locking piece 13. As shown in FIGS. 2 and 3, O ₂ on the side of the cover 12 on the connection tube 11 is a protection protrusion of a screw (not shown), and is a hole O ₃ provided in the steel pipe fitting portion L ₄ . A nut (not shown) is fixed to the inner peripheral surface, and the connection tube 11 and the fitting portion L ₄
And a protruding ring form that protects the screw head from abrasion when the screw is fixed.

[Head 3 (FIG. 5)] Upper half of head 3
Although not shown, the fitting portion L of the steel pipe 10 is_Four With the same structure
And the lower end E of the head 3₀ Has four cutting blades 30
The maximum outer diameter d_Three(Fig. 1) fixed to 720mm
From the vicinity of the lower end of the screw blade 4 _Two
Away from the screw blade 4 (tilt angle 30 °)
Lower end E₀ (Fig. 5 (B))
Supply pipe P_TwoNozzle N at the tip of
Substantially vertically and in the radial direction of the head, a head extension line A-
A has an inclination angle θ of 10 ° in the inner circumferential direction slightly from A,
The screw base S is the lower end E of the head.₀Supply to the form protruding from
Pipe P_Two And the nozzle N are fixed to the head 3 by welding.
did.

[0023] [nozzle N (Figure 6)] nozzles N is a ball-filled check valve structure for screwing the screw cap S detachable to the tip, external water, gravel or the like, from the ejection hole O ₄ The structure is such that it enters the screw cap S but does not flow into the nozzle N. That is, as shown in FIG. 6A, the nozzle N includes an external screw S ₁ for screwing with the end of the supply pipe P ₂ , and an internal screw S ₂ for screwing with the nozzle base S. nozzle holes O ₅ parts are provided with a seating surface 64 of the ball B contact bearing in substantially the center of the nozzle N a smaller diameter than the ball B, the seat surface 6
From 4 becomes larger diameter, has a structure to be engaged with the outer screw S ₃ in nozzle screw S ₂ of the screw cap S and encapsulates the ball B and the coil spring S _P output steel. The screw cap S, the FIG. 6 (B), the as (C), the comprising a TCM 60 for rotating the tip, the large diameter portion 61 from the central portion of the ejection hole O ₄ in the central portion inwardly and it was provided with a notch 62 cut enlarged three places of the peripheral surface of the large-diameter portion 61 to form a seating surface 63 abutting supporting the coil spring S _P to the base of the large diameter portion. Thus, when the assembled nozzle tip seating surface 63 of the coil spring S _P, the bearing surface 64 bearing a ball B, the coil spring S _P is compressed between the ball B and the bearing surface 63 I did it.

[Cap 2 (FIG. 4)] As shown in FIG.
Cap 2 has been made to fit into the fitting portion L ₄ of the upper end of the steel pipe 10, the wall thickness 15 mm, inner diameter be 600 + αmm length which L ₅ 510 mm, i.e., the upper end E ₂ of the steel pipe 10 in the cap upper inner wall fitting portion L ₄ and the cap 2 while abutting is sized to fit, and a connecting tube 11 and the incision O ₁ and the cover 12 having the same structure of the steel pipe 10. The cover 12 is provided with a hanger 22 which is formed by welding a round bar material bent in a U-shape and projecting to the side so that the fitting plate 14 which is not in use can be held.

As shown in FIG. 1, a closed chamber R is formed in the upper wall of the inner surface via a connecting portion J and connected to a high-pressure fluid supply source (not shown). is fixed to a support piece 21 which is welded to the outer periphery of the cap 2 the connection pipe P ₁ is drawn out upward, connecting to the clamping protected form in starting piece and the auxiliary blade 41 of the welding erected the screw blade 4 to the cap bottom pipe P It was installed coupling port P ₀ of _1.

[0026] [fit plate (Fig. 4)] cap and steel, steel pipe and steel pipe, fitting used for connecting the steel pipe and the head plate 14, as shown in FIG. 5, the width W ₀ of the width W _0, i.e. the locking piece 13 A 10 mm thick iron plate having the same width (100 mm) as that of the above, and the upper end is bent and raised to form a locking portion 14 ′, and a handle G extending upward in a loop form is fixed to the locking piece 14 ′. did.

[Connecting Pipe C (FIG. 3)] The connecting pipe C used for communication between the cap and the steel pipe, the steel pipe and the steel pipe, and the high-pressure fluid pipes P ₁ and P ₂ at the connecting part of the steel pipe and the head has couplers K at both ends. Is a flexible tube with an inner diameter of 12 + αmm and an outer periphery covered with a metal knitting, and a coupler K at both ends.
Is the connection port P ₀ of the connection pipe P ₁ and the supply pipe P ₂
This is a conventional member that can be fitted and removed with a single touch.

[Use of Casing] A casing having a height of 9 m to auger joint of a leaderless auger machine was drilled in a casing of 12 m. The assembling of the drilled casing 1 is a connection of the head 3, the steel pipe 10, and the cap 2,
The mounting of the steel pipe 10 on the cap 2 is performed as shown in FIG.
0 an upper fitting portion L ₄ into the cap 2, the width W ₀ (100
mm) and a locking piece 13 having a height H ₁ (150 mm) is fitted into a vertical notch having a width W ₁ (100 + αmm) of the inner surface of the cover and raised, and both are relatively rotated at the position of the side notch to obtain a width. The locking piece 13 is fitted into a side notch of W ₁ and height H ₂ (150 + αmm), and then a fitting plate 14 of width W ₀ (100 mm) is connected to the outer surface of the steel pipe 10 from the upper opening of the cutout O _1. The locking portion 14 ′ is dropped into the cavity having the width W ₁ formed by the cap and the inner surface of the cover 12 until the locking portion 14 ′ abuts on the upper edge of the cover 12. 4 and the cap 2 is connected to the steel pipe 10 (FIG. 4).
(A)).

When the cap 2 and the steel pipe 10 are connected by the fitting plate 14, the lower end of the screw blade 4 and the auxiliary blade 41 on the cap 2 side and the upper end of the screw blade 4 and the auxiliary blade 42 on the steel tube 10 are substantially in contact with each other. since the form and then the connection pipe C, and one-touch fitted the coupler K at both ends to the connecting port P ₀ and the supply pipe P ₂ connecting port P ₀ of the steel pipe 10 side of the connection pipe P ₁ of the cap 2 side, respectively.

Next, the connection between the connection tube 11 at the lower end of the steel pipe 10 and the head 3 is made such that the upper part of the head 3 has the fitting portion L _{4 of the} steel pipe 10.
Identical since the structure a and connecting cylinder 11 is provided with an incision O ₁ of the cap 2 and the same structure after rotating by fitting the upper portion of the head 3 to the connection cylinder 11, crowded dropped fit plate 14 with And the connection of the supply pipe P ₂ is also flexible
With one touch.

[0031] Then, as shown in FIG. 7, connecting the connecting portion J of the cap 2 to the auger swivel unit M _2, sealed chamber R of the cap 2 (not shown) air compressor via the auger swivel unit M ₂ The casing is drilled while spraying high-pressure air from the nozzle N as necessary (when the depth is shallow, high-pressure air is not required to be injected from the nozzle N). stop, slightly rotating the cap 2 by pulling out the fitting plate 14 (rotation up to the locking piece 13 abuts against the side edge of the incision O _1),
The cap 2 was pulled upward.

Next, the 4 m steel pipe 10 shortened only in the length prepared for the extension is connected to the cap 2 in the same manner as the previous time,
Furthermore the fitting portion L ₄ protruding to the surface of the lower end of the connecting tube 11 to the ground of the steel pipe 10 of the relay steel pipe 10, the drop-inclusive fitting and fitting plate 14 of the locking piece 13 and the incision O ₁ ligated and communicates the supply pipe P ₂ by a connecting pipe C to complete the replenishment of the steel pipe 10, and to resume drilling operations to complete drilling to a predetermined depth. Excavation progress work of casing,
The screw blade 4 and the high-pressure air injection from the nozzle N enable drilling to a depth that was impossible with a conventional casing and regardless of the soil properties, resulting in a remarkable improvement in drilling capability more than expected.

In case drilling at the next place after drilling of one casing, when the full length of the relay steel pipe 10 is exposed to the ground, the relay steel pipe 10 and the tip steel pipe (head-mounted steel pipe) 10 are connected. After the fitting plate 14 was pulled out and separated, and the joint steel pipe 10 was removed from the cap 2, the cap 2 was connected to the tip steel pipe 10, the tip steel pipe 10 was pulled up, and the cap 2 was removed from the tip steel pipe 10. The installation and removal of the cap, the steel pipe, the head, and the like could be easily performed as a simple operation in a relatively short time and without any skill because the interconnecting means was simple.

However, if a plurality of machines equipped with the cap 2 and a plurality of steel pipes 10 and a plurality of heads 3 are prepared, the cap 2 and the steel pipe 10, the steel pipe 10 and the steel pipe 10, the steel pipe 10 and the head 3 Since each attachment / detachment is the same means, another head 3 is attached to the end of the intermediate steel pipe 10 at the stage where the intermediate steel pipe 10 is pulled up after one casing drilling is completed and separated from the tip steel pipe underground, and a new casing is formed. It is also possible to perform drilling and work to add the steel pipe 10 at the end of the excavation of the intermediate steel pipe 10, thereby streamlining the work of attaching and detaching the cap and the steel pipe.

[0035]

[Study of operation and effect] [Screw blade] Using a leaderless auger machine (small machine), a place with relatively good geological conditions was drilled with a conventional drilling casing (steel pipe with a cutting blade at the tip). Drilling up to about 5-6m was possible,
Beyond that, due to the outer and inner friction of the casing, drilling became impossible even when a cutting blade for hard rock was installed. In addition, when drilling a layer hardened with viscous earth and sand with a conventional drilling casing, the work is temporarily suspended and when resuming, the frictional resistance to the inner and outer peripheral surfaces of the casing increases during the suspension time. As a result, the starting rotation of the casing became impossible.

Since the casing of the present invention is provided with the screw blades 4 on the entire circumference, the screw blades 4 perform the function of the auger screw blades, excavate while excavating the cutting soil, and advance with respect to the outer peripheral surface of the casing 1. The frictional force of the ground has been extremely reduced. Moreover, the blade pitch was around 60 cm and the blade width was 50 mm, so that it effectively acted on all strata. As a result of trial test, blade width is 50mm
Below, the sand discharging capacity was low, and at about 100 mm, the adhesion of the viscous soil was remarkable, and the effect of reducing the frictional force was reduced. At a pitch of about 30 cm, a phenomenon occurs in which the pressure-bonded clay fills the gap between the blades. On the other hand, at a pitch of about 1 m, the ability to lift the cutting soil is reduced.

[Nozzle Injection] A nozzle N is provided at the tip to drill a hole while injecting high-pressure air (water) into the excavation part. Therefore, it is possible to prevent the adhesion of cutting soil to the cutting blade and reduce the cutting ability of the head. I was able to stop it. As a result of the trial test, the direction of injection from the nozzle N is such that the exhaust air all rises along the outer periphery of the casing on the extension line of the outer periphery of the head 3, that is, the line AA in FIG. The effect of reducing the frictional force could not be expected. In the present embodiment, the ejection direction from the nozzle N is ejected inward from the outer peripheral extension line AA of the head 3 at an angle θ (10 °) as shown by a line FF in FIG. 5B. Approximately half of the discharged air is guided to the inner surface of the casing 1 along the inner peripheral wall of the head 3 to reduce the friction of the inner peripheral surface of the drilled casing 1. The frictional resistance could be reduced by the rising air discharged from the nozzle N.

However, if the angle θ is increased, the function of preventing the cutting soil from adhering to the cutting blade is reduced. Therefore, the effect of reducing the frictional force on the inner and outer circumferences of the casing and the function of preventing the cutting ability of the cutting blade from being effectively reduced by the high-pressure jet flow. Angle θ is 5
The angle is preferably in the range of 15 to 15 °. In the present embodiment, the injection of the high pressure air at an angle θ of 10 ° and the action of the screw blade 4 are combined, and depending on the soil quality, the frictional resistance value is about 1/10 of that of the conventional bladeless casing (at each location). The same performance as casing drilling on a large machine of 80t or more even though it is a small machine of 20-30t class (leaderless auger machine) by using the drilled casing 1 of the present invention. Drilling of casings of more than that is now possible.

[Nozzle] When the coil spring _SP is omitted: the screw base S is a ball-sealed check valve, that is, the ball B receives the pressure of the high-pressure fluid from the nozzle N and moves the ball B from the nozzle hole end to the screw base inlet side. in those Sessure the large diameter portion 61, the ball B and is the flow path formed from the gap between the notch 62 of the three positions of the large-diameter portion periphery to ejection hole O ₄ and allows fluid injection supply pipe P ₂ is ambient pressure if a is pressed against the nozzle opening ball B while allowing entry into the nozzle hole O ₅ in some of sediment flowing back by entering from the ejection hole O ₄ of sediment by external soil pressure, the nozzle N When the nozzle N is started, the ball B moves together with the sediment in the screw base and the screw base S when the nozzle N is started.
Collides with the large diameter portion 61, and the base and the ball are severely worn.
Therefore, the screw cap material is made more wear-resistant, and the ball cap steel is used as a wear replacement member to remove the screw cap S from the nozzle N and replace the ball when the ball is worn. Therefore, it is necessary to repair the screw base every 10 days in a work of 5 hours a day, but the repair work is only to replace the new and old balls by turning the screw base S and removing it from the nozzle N.
The work was simple, and the intended purpose was achieved even with the nozzle N in which the coil spring _SP was omitted.

[0040] When using a coil spring S _P: supplying high pressure air (water) to the feed pipe P _2, when the nozzle N is injection start, blow at the moment the ball B but the ball B
No direct collision between the large diameter portion 61 end of the ball B and the screw cap S be only pressed against the coil spring S seating surface 63 of the coil spring S _P instantaneously with soil which has entered around the _P is. Thus, the ball B, since only wear by the pressing of the friction and the coil spring S _P output and intrusion sediment at the start of the nozzle N, about 1/10 of than in the case where wear of the ball without a coil spring The wear of the coil spring rather than the ball was faster than that of the ball.

[0041] However, the coil spring S _P is inexpensive, because the replacement is also easy, the adoption of the coil spring is advantageous. Of course, in the case of employing the coil spring S _P, because at the same time the ball B and the nozzle pause closes the nozzle hole O ₅ quickly by the return force of the coil spring, sediment from entering the nozzle holes O ₅ is always possible to prevent The nozzle clogging due to abrasion of the nozzle N and penetration of earth and sand was minimized. In the case of drilling the casing, since the operation of attaching and detaching the drilled casing 1 and the maintenance of the nozzle N greatly affect the operation rate, the adoption of the coil spring in the nozzle N has brought an unexpected result in terms of work efficiency.

[Others] Although the intended object of the present invention can be achieved by applying the screw fixing means as the attaching and detaching means for the cap 2 and the steel pipe, the steel pipe and the steel pipe, and the steel pipe and the head, the case where the screw fixing means is applied the, for example 2, such as protective projections O ₂ shown in FIG. 3, it is advantageous if Kojire galling measures of the screw head generally crop on the outer peripheral surface of the casing 1. Further, it is advantageous that the fixing means at each part has the same structure from the viewpoint of assembling work and maintenance. Of course, if necessary, the joint use of the fitting plate connecting means (means of claim 6) and the screw fixing means is reliable and effective, and is particularly effective for drilling a deep casing.

[0043] Further, in the embodiment, but in communication with the fluid supply side via the sealed chamber R in the cap 2 the upper end of the feed pipe P _2, of course, the supply pipe P _2, skip sealed chamber R connected The intended purpose of the invention can be achieved by communicating with the department J. The width dimension and winding pitch of the screw blade 4 is subject soil, and can be variously changed under the condition of the steel pipe diameters, it is also possible to screw vane integrally provided with the pipe P _2. Further, if the bar-shaped piece is inclinedly welded in the same direction as the screw blade 4 at the appropriate position on the inner peripheral surface of the steel pipe 10, it is advantageous to reduce the earth and sand friction on the inner peripheral surface, and the steel pipe main body has a length that does not affect strength. If a hole is formed, it is convenient for welding to the inner surface of the rod-shaped piece, and the long hole is also advantageous for reducing the earth and sand frictional force on the entire steel pipe by forming a passage for soil and air between the inner surface and the outer surface of the steel pipe.

Since an increase in the diameter of the casing increases the frictional force on the peripheral surface, a large-diameter casing may be provided with a plurality of spiral blades and supply pipes and a plurality of injection nozzles at the head end. Fluid injection effect (prevention of reduction in cutting power of the cutting blade and extreme reduction of frictional force on the inner and outer surfaces of the casing) can be sufficiently exhibited. The high-pressure jet fluid from the nozzle N is usually air, but depending on the operating conditions,
Water, cement milk, and the like are also effective, and the pressure of the jet fluid is a matter of design that is naturally determined according to the construction conditions.

[0045]

While the casing is being excavated, the frictional force of the outer peripheral surface of the casing against the ground is extremely reduced by the lifting action of the excavated soil by the screw blade 4, and the high-pressure jet from the nozzle N causes the high-pressure jet flow of the cutting blade. The drilling force in the soil is prevented from lowering, and the upward flow discharged from the nozzle N also has a frictional force reducing effect on the ground on the peripheral surface of the casing, so that the drilling capacity of the drilling casing is extremely increased. In addition, the drilling power can be extremely reduced, so that even a small machine with a small power can perform as large or larger than a large machine, and even in a large machine, energy saving of casing drilling can be achieved. Then, in order to supply the high-pressure fluid to the nozzle N
Feed pipe P ₂ of the intake to the lower surface base of the screw blade 4
Since the attached, feed pipe P _2, the casing 1
Of the screw blade 4 during excavation during drilling
Without receiving the frictional force from the excavated soil
Abrasion damage can be prevented and screw blade guide machine
Does not impair the ability .

Further, since the injection of the high-pressure fluid from the nozzle N is more inward of the head than the extension direction of the steel pipe, during the drilling of the casing 1, the high-pressure flow ejected from the nozzle N assists the cutting action of the cutting blade. Not only does the exhaust fluid
The ascending flow occurs not only on the outer circumference but also on the inner circumference of the head and the steel pipe, causing a friction reduction effect on the outer wall and the inner circumference of the steel pipe, and the frictional resistance due to the ground of the drilled casing can be extremely reduced. .

Further, since a cap, a steel pipe and a head having the same detachable structure are employed, assembling, separation and maintenance of the casing are facilitated, the length of the casing can be freely set according to the working conditions, and the use of casing drilling is applicable. The field is expanding, and the value of using the casing drilling method increases.

[Brief description of the drawings]

FIG. 1 is an overall schematic side view of the present invention.

FIG. 2 is a view showing a connecting portion between steel pipes of the present invention,
(A) is a plan view and (B) is a perspective view.

FIG. 3 is an exploded plan view of a connecting portion between steel pipes according to the present invention.

FIGS. 4A and 4B are views of the cap portion of the present invention, wherein FIG. 4A is a perspective view of a connected state, and FIG.

5A and 5B are views of the head section of the present invention, wherein FIG. 5A is a perspective view of the entire head, and FIG.

6A and 6B are views of the nozzle of the present invention, wherein FIG. 6A is an exploded perspective view, FIG. 6B is a plan view of a screw cap, and FIG. 6C is a side view of the screw cap.

FIG. 7 is a schematic view of a use state of the casing of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Hole drilling casing, 2 ... Cap, 3 ... Head, 4 ... Spiral blade, 10 ... Steel pipe, 11 ...
Connection tube, 12 ... cover, 13 ... locking piece, 14 ...
Fitting plate, 20: top plate, 21: support piece, 22: hanger, 30: cutting blade, 41, 42: auxiliary blade,
60 ... square head, 61 ... large diameter part, 62 ... notch, 6
3, 64: seat surface, C: connecting pipe, G: handle,
J: Connection, K: Coupler, N: Nozzle, O ₁
..Incision part, O ₄ ... ejection hole, O ₅ ... nozzle hole, P _0.
..Connection port, P ₁ ... connection pipe, P ₂ ... supply pipe,
R · · · sealed chamber, S · · · screw _{cap, S 1, S 2, S} 3 ··· screw

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E21B 7/20 E02D 17/08 E02D 17/22

Claims (11)

(57) [Claims] 1. A steel tube screw blades (4) on the outer periphery (10) mounted winding, while attaching a supply pipe (P ₂₎ along the lower surface base <br/> the screw blade (4), supplied A drilling casing for civil engineering work in which an upper end of a pipe (P ₂ ) communicates with a fluid supply side, and a lower end communicates with a high-pressure fluid injection nozzle (N) attached to a digging portion at the tip of a head (3). 2. A closed chamber (2) removably fitted to an upper end of a steel pipe (10), and a closed chamber (4) communicating with a fluid supply source via a connection portion (J) on an inner upper surface of the cap (2). provided with a R), said closed chamber (R) and the supply pipe (P ₂₎ communicated via a coupler (K) and the upper end, civil engineering for drilling casing of claim 1. 3. The drilling casing for civil engineering work according to claim 1, wherein a plurality of steel pipes (10) are connected and connected by connecting the screw blades (4) and the supply pipe (P ₂ ) in a communicating state. 4. A connecting cylinder (11) is fitted and fixed to a lower end of a steel pipe (10), and an upper end of another steel pipe (10) is connected to the connecting cylinder (11).
The drilling casing for civil engineering work according to any one of claims 1 to 3, wherein the steel pipe (10) is removably extended by being fitted and locked in the inside. 5. A width (W ₀ ) and a height (H) on the outer periphery of the upper portion of the lower steel pipe (10) which are substantially the same as the thickness of the connecting tube (11).
₁ ) is attached, and the upper steel pipe (1) is attached.
0) The connecting tube (11) at the lower end is provided with an incision (O ₁ ) for guiding the locking piece (13) upward from the lower end and allowing subsequent lateral movement, and the incision ( O ₁ ) The cover (12) is placed and fixed in place on the surface, and the engaging piece (13) of the lower steel pipe (10) is moved to the side in the incision (O ₁ ) and the fitting plate (14). On drop into incision (O ₁₎ of any one of civil engineering for drilling casing of claims 1 to 4. 6. A lower part of the connection cylinder (11) and a steel pipe (10) fitted therein.
The screw blade (4) at each end of the upper juxtaposed auxiliary blades (41, 42) so as to sandwich the feed pipe _{(P 2)} end of the steel pipe (10) the upper end of the connecting tube (11) connecting the connection tube during fitting stop (11) provided on the pipe (P ₂₎ lower and fitting the steel pipe (10) supplying on the pipe (P ₂₎ connected between the upper pipe (C), to claim 1 Item 5. The drilled casing for civil engineering work according to any one of Items 5 to 5. 7. Cap (2) and steel pipe (10), steel pipe (10) and steel pipe (10), steel pipe (10) and head (3)
The drilling casing for civil engineering work according to any one of claims 2 to 6, wherein the attachment and detachment are performed by the same connecting means. 8. The drilling casing for civil engineering work according to claim 7, wherein the connecting pipe (C) is flexible and has couplers (K) at both ends. 9. The drilling casing for civil engineering work according to any one of claims 1 to 8, wherein the nozzle (N) is provided with a screw cap (S) of a check valve at a tip thereof in a detachable manner. 10. A nozzle hole (O ₅ ) in a nozzle (N).
A ball (B) for closing is inherent, and a coil spring (S _P ) is interposed between the ball (B) and the base end of the screw base (S) to connect the screw base (S) to the tip of the nozzle (N). The drilling casing for civil engineering work according to any one of claims 1 to 9, screwed into the casing. 11. The jetting direction of the nozzle (N) (line FF)
11. The drilling casing for civil engineering work according to any one of claims 1 to 10, wherein is a direction slightly inward of the head (3) from the direction in which the head 3 extends (line A-A).