JPH0718665A - Screw rod for underground boring machine - Google Patents

Abstract

PURPOSE:To increase the ground strength and quickly and easily carry out execution by providing spiral blades on the outer periphery, and longitudinally providing an air feed passage and a cement milk feed passage inside. CONSTITUTION:The compressed air from an external compressor is guided to the first connecting passage 36 penetrating the connecting shaft section 32 of a rotary joint 30 via a flexible pipe 42 and the swivel device of a power device section, it is fed to an excavating bit 72 from the passage 36 through a screw rod 50 and an air feed passage 45A provided on an air hammer 60, and the bit 72 is vertically vibrated for the boring work. Slime is discharged onto the ground by the rod 50 and spiral blades 52, 62 of the hammer 60. Cement milk is guided to the second connecting passage 37 formed on the connecting shaft section 32 from the horizontal passage 35 of the joint 30, it is further guided near the tip section of the air hammer 60 through a cement milk feed passage 46A, a valve 78 is opened by the feed pressure, and the cement milk is sprayed outward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel screw rod for an underground drilling machine which is capable of supplying cement milks as a soil reinforcing material to the outside.

[0002]

2. Description of the Related Art Generally, in civil engineering foundation work, in order to increase the strength of foundation ground support, board piles (site construction piles) are laid in the ground, PC piles, H beam piles, etc. Although stress-bearing materials such as steel piles are inserted, when drilling a stratum, a boulder layer, a gravel layer, etc. where a large amount of water is produced by conventional construction methods, the drilled holes that have been drilled often collapse. However, there is a problem that the stress-bearing member cannot be inserted to the depth of the hole. Even if the pile or the like can be inserted to the maximum depth of the drilled hole, the pile or the like may sink because the ground supporting force is insufficient.

[0003]

In order to avoid the above problems, conventionally, for example, a cylindrical iron pipe is driven into an excavation hole drilled by an underground drilling machine by a method such as pile driving, and then the driving is performed. After removing the soil in the cylindrical iron pipe that has been removed, the cement paste is injected into the pipe, and a construction method is proposed in which the cylindrical iron pipe is separately pulled out by a hoist during this cement curing. In the construction method of, multiple work of different types such as drilling work, insertion work of cylindrical iron pipe, soil removal and cleaning work inside the cylindrical iron pipe, cement injection work into the pipe, pulling up of the cylindrical iron pipe, etc. are performed in a certain order. Because it has to be done separately,
In addition to requiring a plurality of different equipment, there is a problem that it takes a lot of time and labor to change the equipment, resulting in a high construction cost.

In the conventional underground drilling machine used for the civil engineering foundation work as described above, an excavating bit, which is normally vibrated vertically by compressed air, is provided in the lower stage of a screw rod provided with spiral blades on the outer periphery. Is connected to the air hammer, the upper end of the screw rod is connected to a power unit for driving them in rotation, and the power is generated while being guided by a leader mast arranged on the ground. It can be moved up and down together with the device.

[0005] The applicant of the present application has proposed an underground drilling machine equipped with a screw rod having an air hammer connected to the lowermost stage in order to increase the strength of the foundation ground support without causing the above problems. , A soil reinforcement material such as cement milk is jetted from near the tip of the air hammer. If an underground drilling machine capable of ejecting cement milk from the vicinity of the tip of the air hammer is developed in this way, drilling holes drilled during drilling work or when pulling up the screw rod and air hammer after drilling work. Cement milks can be supplied or sprayed so as to form a wall on the inside or the inner peripheral surface of the ground, which can increase the formation strength and make it difficult for the drill hole to collapse. The original shape can be maintained and the pile etc. can be easily inserted into the excavation hole, and since the frictional force around the pile etc. increases, it is possible to minimize the sinking amount of the pile. Drilling work, insertion of cylindrical iron pipe, soil removal and cleaning work inside the cylindrical iron pipe, cement injection work inside the pipe, pulling up of the cylindrical iron pipe, etc. Since it is not necessary made people in, performing the construction quickly and easily, so that the revolutionary effect of drastically reduced construction cost can be obtained.

However, as described above, in order to eject the cement milk from the vicinity of the tip of the air hammer in the underground boring machine, compressed air for driving the air hammer (for excavating the excavation bit) and cement through the screw rod. It is required to guide milk and the like to an air hammer connected to the lower stage of the screw rod, but a screw rod capable of meeting such demand has not yet been developed.

In view of the above point, the present invention has an object of providing a screw rod capable of supplying compressed air and cement milk to an air hammer in an underground drilling machine.

[0008]

In order to achieve the above object, a screw rod for an underground drilling machine according to the present invention comprises:
A spiral blade is provided on the outer periphery, and an air supply passage and a cement milk supply passage are provided in the interior so as to extend vertically. In this case, it is preferable that part or all of the cement milk supply passage is formed of a pipe.

More preferably, the upper and lower ends are respectively formed of a plug portion and a socket portion into which the plug portion is fitted, and a pipe constituting a cement milk supply passage is bridged between the plug portion and the socket portion. The ones that have been done are listed.

[0010]

[Operation] In an underground drilling machine using the screw rod according to the present invention configured as described above, the screw rod and the air hammer are connected to the power unit through an appropriate joint such as a swivel device. The screw rod and the air hammer are rotated, and are moved up and down while being guided by the leader mast together with the power unit.

At this time, compressed air from an external compressor is introduced into the air supply passage of the screw rod through a swivel device or the like arranged in the power unit, and the compressed air is excavated through the air supply passage provided in the air hammer. It is given to the bit, whereby the drill bit vibrates in the vertical direction for drilling work, and at the same time, in the cement milk supply passage of the screw rod,
Cement milk from a cement milk supply device consisting of an external cement mixer, etc. is introduced through a conduit etc., and this cement milk is passed from the vicinity of the tip of the air hammer to the outside through the cement milk supply passage provided in the air hammer. It is jetted toward.

As described above, the screw rod of the present invention can guide both compressed air and cement milk supplied from the outside to the air hammer, and therefore,
According to an underground drilling machine using such a screw rod, during the drilling work or after the drilling work, a wall is formed with cement milks inside or inside the drilled hole drilled when the air hammer is pulled up. It is possible to supply or spray, and it is possible to increase the formation strength even on soft ground, etc., and it is possible to prevent the excavation hole from breaking easily.As a result, the original shape of the excavation hole can be maintained and piles etc. can be maintained. It can be easily inserted into the excavation hole, and because the frictional force around the pile etc. increases, it is possible to minimize the sinking amount of the pile, making the construction quick and easy, and the construction cost Can be drastically reduced.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of an underground drilling machine to which an embodiment of the screw rod according to the present invention is adopted. Figure 1
In the underground drilling machine 10 shown in FIG. 1, a leader mast 12 is vertically provided at the front end of a crawler-type base vehicle 11, and a top of a pulley mechanism 14 disposed on the top of the leader mast 12 is installed. Sheave block 15
The power unit 20 and the rotary joint 30 according to the present invention, the screw rod 50, and the air hammer 60 are integrally connected and suspended by the wire 17 that is hung from the buffer unit 16 via the shock absorbers 16.

The power unit 20 comprises a rectangular frame-shaped lifting housing 21, a geared motor 22, and a swivel device 24. The elevating housing 21 is supported by two guide rails 18 provided on the front surface of the leader mast 12 so as to be vertically movable via slide metal fittings 19. A geared motor 22 is fixed in the lifting housing 21, and a compressor (not shown) arranged outside the geared motor 22 on the output side.
A swivel device 24 is connected to which compressed air from is introduced through a flexible conduit 42. In addition, the base vehicle 11, the leader mast 12, the pulley mechanism 14, the elevating housing 21, the geared motor 22, which are described above,
The configuration of parts other than the rotary joint 30, the screw rod 50, and the air hammer 60, such as the swivel device 24, is basically the same as that of the existing underground boring machine.

The rotary joint 30 connected to the lower side of the swivel device 24 is constructed as shown in FIGS. That is, the rotary joint 30 is fixed to the elevating housing 21 of the power unit 20 by the bolts 27 and its rotation is restricted, and together with the power unit 20, the leader mast 1 is rotated.
It comprises a bearing portion 31 which is guided by the second guide rail 18 and can be moved up and down, and a connecting shaft portion 32 which is rotatably fitted and held in the bearing portion 31.

Specifically, the bearing portion 31 is a base body 3 fitted onto the outer periphery of the central large diameter portion 32A of the connecting shaft portion 32.
1A and a pair of rolling bearing members 31B fixed to both ends thereof by bolts 33 to receive the upper and lower small diameter portions 32B of the connecting shaft portion 32 in the radial direction and the outer peripheral edges of the upper and lower ends of the central large diameter portion 32a in the thrust direction. The base 31A portion of the bearing portion 31 is fixed to the elevating housing 21 by a bolt 27.
A horizontal passage 35 is formed in the portion A so as to penetrate the inside and outside in the horizontal direction, and a flexible conduit 44 for cement milk is connected to the outer end of the horizontal passage 35.

Further, the connecting shaft portion 32 is shown in FIGS.
An air supply passage 45 provided in a screw rod 50 described later so as to pass through the central axis thereof as shown in FIG.
The first connecting passage 36 communicating with A is provided so as to penetrate therethrough, and the lateral passage 3 formed in the bearing portion 31.
The second connection passage 37 is formed so as to connect the No. 5 and the cement milk supply passage 46A provided in the screw rod 50 described later. Second connection passage 37
As shown in FIG. 3, an annular path 37a, which is a groove formed in the inner peripheral portion of the bearing portion 31 and an outer peripheral portion of the connecting shaft portion 32, faces the annular passage 37a toward the center. Of a pair of lateral holes 37b, 37b formed so as to
The vertical holes 37c and 37c are formed straight downward from the bottoms of the horizontal holes 37b and 37b.

The upper end portion of the connecting shaft portion 32 is fixed to the coupling tool 24a connected to the lower portion of the swivel device 24 by the bolt 41 via the flange 38A, and the lower end portion is fixed to the flange portion 38B with the bolt 41. Socket part 55
Is connected to the upper end portion (plug portion 54) of the screw rod 50 described later. The swivel device 24 and the connecting shaft portion 32 may be connected to each other by using a plug portion 54 and a socket portion 55 used for connecting a screw rod 50, which will be described later, instead of the connecting tool 24a. .

As shown in FIG. 5, the screw rod 50 has a plug portion (male joint) in which a fitting convex portion 54a having a regular hexagonal cross section is formed at an upper end portion of an outer cylindrical portion 51 as shown in FIG. ) 54 is attached, and a socket portion (female joint) 55 having a fitting recessed portion 55a having a regular hexagonal cross section to be fitted into the fitting protruding portion 54a is formed at the lower end portion thereof as shown in FIG. A spiral blade 52 is provided on the outer circumference of the outer cylinder portion 51 and the socket portion 55.

An air supply passage 45A and a cement milk supply passage 46A are provided so as to extend vertically through the screw rod 50. Specifically, the air supply passage 45A is provided between the plug portion 54 and the socket portion 55 so as to pass on the center line of the screw rod 50.
The pipe 45a forming the air supply passage 45A is bridged, and the pipes 46a and 46a forming the middle portion of the cement milk supply passage 46A are bridged on both sides of the pipe 45a forming the air supply passage 45A. 54 and the socket portion 55 have through holes 54b, 54c, 54c and 55b, 55c, 5 forming the both ends of the air supply passage 45A and the cement milk supply passages 46A, 46A.
5c is formed.

Further, at both ends of the pipe 45a constituting the air supply passage 45A and the pipes 46a, 46a constituting an intermediate portion of the cement milk supply passage 46A, a metal disc inscribed in the outer cylinder portion 51 is formed. Partition plate 92,
92 is attached, and the pipe 45a,
A steady rest 80 is attached to the central portion of each of 46a and 46a.

In the screw rod 50 having such a structure, the screw rods 50 having the same structure are sequentially arranged in accordance with the depth of the excavation hole to be drilled, as shown in FIG. And their top surface −
Pin insertion parts 57, 57, 58, 5 provided at different positions on the left and right sides of the plug part 54 and the socket part 55 by fitting them with a rubber packing 43 interposed between the bottom surfaces.
The spring pins 56 and 56 are inserted into 8 respectively to be connected. In addition, the connection between the screw rod 50 and the rotary joint 30 (FIG. 2) and the connection between the screw rod 50 and an air hammer 60 described later are performed in the same manner.

As shown in FIG. 9, the air hammer 60 connected to the above-mentioned screw rod 50 is provided with a spiral blade 62 connected to the spiral blade 52 of the screw rod 50 on the outer periphery thereof, and inside thereof, A well-known excavation bit 72 vibrating mechanism including an air supply passage is provided, and a cement milk supply passage is provided, but a detailed description thereof will be omitted here to avoid complicated description. The above-mentioned excavating bit vibrating mechanism is disclosed in, for example, Japanese Patent Laid-Open No. 55-198885, and the one in which a cement milk supply passage is provided in addition to the excavating bit vibrating mechanism is disclosed in Japanese Patent Application No. 5-53200. -9
No. 3145, etc., respectively, so refer to them if necessary.

When performing the drilling work by the underground drilling machine 10 configured as described above, the power unit 20 and the screw rod 50 and the air hammer 60 connected thereto via the rotary joint 30 are lowered while the motor is being driven. 22 is driven. As a result, the connecting shaft portion 32 of the rotary joint 30 and the screw rod 50 rotate integrally and are guided by the guide rail 18 of the leader mast 12 and lowered.

At this time, compressed air from an external compressor is introduced into the flexible conduit 42 in the first connecting passage 36 penetrating the connecting shaft portion 32 of the rotary joint 30.
And is introduced through the swivel device 24 of the power unit 20, and the compressed air is supplied to the excavation bit 72 from the first connection passage 36 through the air supply passage 45A provided in the screw rod 50 and the air hammer 60,
As a result, the excavation bit 72 vibrates in the vertical direction as described above, and a drilling operation similar to that of a normal underground drilling machine is performed. The slime created at this time is screw rod 50
And the spiral blades 52 and 62 of the air hammer 60 discharge the soil to the ground.

In the case where the soil on which the boring work is performed is likely to collapse in this way, the power unit 20 and the screw rod 50 are dug after reaching the required depth.
When pulling up the air hammer 60, the cement milk supply device including an external cement mixer is operated to operate the bearing portion 3 of the rotary joint 30.
Cement milk is supplied to the lateral passage 35 formed in No. 1 through the flexible conduit 44 at a predetermined pressure. As a result, the cement milk becomes rotary joint 30.
From the horizontal passage 35 to the second connecting passage 37 (annular passage 37a, horizontal hole 37b, vertical hole 37c) formed in the connecting shaft portion 32, and further from the second connecting passage 37 to the screw rod 50 and the air hammer 60. The cement milk is supplied to the vicinity of the tip of the air hammer 60 through the cement milk supply passage 46A, and the supply pressure thereof causes the valve 78 to open and the cement milk to be ejected to the outside. In this case, since the screw rod 50 and the air hammer 60 are rotating, as shown in FIG. 9, cement milk is ejected laterally to form a wall toward the inner peripheral surface of the drilled hole 100. Is sprayed on, by which
The original shape of the drilled hole 100 is preserved as it is.

Therefore, according to the underground drilling machine 10 using the screw rod 50 of the present invention, the screw rod 50 and the air hammer 6 during or after the drilling work.
Cement milks can be supplied or sprayed to the inside or the inner peripheral surface of the hole 100 drilled at the time of pulling up 0, the formation strength can be increased, and the drill hole 100 can be prevented from easily breaking, as a result,
The original shape of the excavation hole 100 can be maintained and piles etc.
0 can be easily inserted, and because the frictional force around the pile etc. increases, it is possible to minimize the sinking amount of the pile, which enables quick and easy construction and reduces construction costs. It can be drastically reduced.

The screw rod is not limited to the one having the structure as in the above-mentioned embodiment, but has a structure in which the pipe 45a constituting the air supply passage 45A is removed as shown in FIG. 10, for example. Alternatively, as shown in FIG. 11, a solid rod in which passages 45A and 46A are perforated can be used.

[0029]

As can be understood from the above description, the screw rod for an underground drilling machine according to the present invention can introduce both compressed air and cement milk supplied from the outside into an air hammer, Therefore, according to an underground drilling machine using such a screw rod, a wall of cement milk is made on the inside or the inner peripheral surface of the drilled hole drilled during the drilling work or the lifting of the screw rod and the air hammer after the drilling work. As described above, it is possible to supply or spray the soil, so that it is possible to increase the strength of the formation even in soft ground, etc., and it is possible to prevent the excavation hole from breaking down easily. Etc. can be easily inserted into the excavation hole, and the amount of subsidence of the pile is minimized because the frictional force around the pile etc. increases. It becomes possible to suppress the rapid and construction and easy to, there is an advantage that it drastically reduce construction costs.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an underground drilling machine in which an embodiment of a screw rod according to the present invention is used.

FIG. 2 is a vertical sectional view of a rotary joint of the underground drilling machine of FIG.

3 is a cross-sectional view of the rotary joint of FIG.

FIG. 4 is a vertical sectional view of a connecting shaft portion of the rotary joint shown in FIG. 2;

FIG. 5 is a sectional view of an embodiment of a screw rod for an underground drilling machine according to the present invention.

6 is a plan view of the screw rod of FIG.

FIG. 7 is a bottom view of the screw rod of FIG.

FIG. 8 is a diagram which is used for describing a connection state of screw rods.

FIG. 9 is a diagram provided for explaining a usage state of the underground drilling machine of FIG. 1.

FIG. 10 is a view showing another example of the screw rod.

FIG. 11 is a view showing another example of the screw rod.

[Explanation of symbols]

10-Underground drilling machine 12-Leader mast 20-Power unit 21-Elevating housing 22-Geared motor 24-Swivel device 30-Rotary joint 45A-Air supply passage 45a-Pipes constituting air supply passage 46A-Cement milk supply Passage 46a-Pipe that constitutes an intermediate portion of the cement milk supply passage 50-Screw rod 52-Spiral blade 54-Plug part 55-Socket part 56-Spring pin 60-Air hammer 100-Drilling hole

Claims (3)

[Claims] 1. A screw rod for an underground drilling machine, wherein a spiral blade is provided on the outer periphery, and an air supply passage and a cement milk supply passage are provided in the interior so as to extend vertically. 2. A part or all of the cement milk supply passage is formed of a pipe.
Screw rod for the underground drilling machine described. 3. The upper and lower ends are each formed of a plug part and a socket part into which the plug part is fitted, and a pipe constituting a cement milk supply passage is bridged between the plug part and the socket part. The screw rod for an underground drilling machine according to claim 1 or 2, characterized in that