JPH0546433B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a boring head for drilling holes for pile driving.

<Prior art and its problems> Various heads attached to the tip of an earth auger or the like have been used to excavate holes for field-driven piles.

For example, those shown in FIGS. 1 and 2 are widely used. In both figures, the head 10 has a hollow tube 12 having a through hole 11 for passing a fluid such as water or air for drilling, and a control valve 13 is provided at the lower end of the through hole. 14 is a tip blade for driving the hole.

A spiral wing 15 is fixed to the hollow tube 12 in the example shown in FIG. 1, and a spear-shaped wing 15 in the example shown in FIG. In addition to these claws 16, the hollow tube 21 also has claws that close during normal rotation (during excavation),
Enlargement wings 17 are attached that open when the vehicle is reversed.

In these conventional heads, the former claw 16
A head with a chisel is used in the pre-boring method, cement milk method, etc., and the latter has a claw 16
In addition to this, the head having the enlarged blade 17 can be used for kneading construction method, low index construction method, CMG construction method,
It is used in NAX construction methods, etc.

In conventional heads, such as the above-mentioned heads, the accuracy of centering the shaft portion of the excavating auger that is buried in the soil and the head attached to the tip thereof is not good. That is, the deviation of the shaft portion and the head from the vertical direction increases as the excavation depth increases. That is, it is not possible to drill a hole that is vertically downward and has a constant diameter. This is because as the soil depth increases, the position of the head gradually shifts from the vertical direction to a somewhat oblique direction, that is, to the horizontal direction.

Furthermore, there are many obstacles in the soil, such as cobblestones, concrete pieces from the old base, and bedrock, which prevent the head from advancing into the soil, and these also cause the vertical downward excavation direction of the head to deviate diagonally downward. I end up.

Therefore, in conventional heads, the diameter of the excavated hole increases as the soil depth increases, or the hole is formed diagonally downward.

Since such holes are not suitable for piling out,
This has caused inconveniences such as having to re-excavate.

<Object of the Invention> Therefore, an object of the present invention is to prevent the head from proceeding diagonally during excavation, and thereby prevent the hole diameter from increasing as the depth increases, and to drill the hole to a required depth (to the supporting layer). ) It is an object of the present invention to provide a boring head that has a constant hole diameter and is capable of drilling a straight hole vertically downward, with good centering accuracy.

Still another object of the present invention is to provide a boring head that can cut through underground obstacles such as old bases and bedrock, and can be used in a wide range of applications such as continuous column row excavation and bottom-expanding excavation. .

<Configuration of the Invention> The present invention provides a hollow pipe having a through hole for water passage;
a hollow cylindrical body arranged concentrically with the hollow tube; and a plurality of partition walls arranged between the hollow tube and the cylindrical body so as to fix the cylindrical body to the hollow tube. a plurality of claws provided on the cylindrical body and/or the partition wall so as to protrude in the excavation direction; and at least one claw formed on the peripheral wall of the cylindrical body.
and a door installed in the window so as to close when the head is rotated in the digging (forward rotation) direction and open when the head is rotated in the reverse direction, and the length of the cylindrical body is L, the diameter is R, and the wall thickness is T, then L≧R/10 R/10≧T≧R/100, and the inclination angle of the window provided in the cylindrical body from the reverse direction to the excavation direction is α. When 0≦α≦
45°, and 0≦β≦45°, where β is the inclination angle in the normal rotation direction from the excavation method of the claws provided on the cylindrical body and/or the partition wall. This is what we provide.

The present invention also provides a hollow tube having a through hole for water passage, a hollow cylindrical body disposed concentrically with the hollow tube, and a cylindrical body fixed to the hollow tube. A plurality of partition walls arranged between a hollow tube and the cylindrical body, a plurality of claws provided on the cylindrical body and/or the partition wall so as to protrude in the excavation direction, and a peripheral wall of the cylindrical body. at least one window formed in the window and drilling a head (normal rotation) within this window
Formed on the peripheral wall of the hollow tube so as to communicate with the through hole of the hollow tube and a door attached to close when rotated in a direction and open when rotated in a reverse direction, and to inject water toward the window. When the length of the cylindrical body is L, the diameter is R, and the wall thickness is T, L≧R/10 R/10≧T≧R/100, and the cylindrical body has a bypass path. When the angle of inclination of the provided window from the reverse direction to the excavation direction is α, 0≦α≦
45 degrees, and 0≦β≦45 degrees, where β is the inclination angle in the normal rotation direction from the excavation method of the claws provided on the cylindrical body and/or the partition wall.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The boring head of the present invention will be described in detail below with reference to the drawings. In the drawings, parts that are the same as in the prior art are designated by the same numbers. The fundamental difference between the boring head of the present invention and conventional heads lies in the provision of a hollow cylindrical body arranged concentrically with the hollow tube. Even if there is a problem, the entire head can be immediately dug vertically downward into the soil without deviation in the lateral (horizontal) direction.

First, a first embodiment of the boring head of the present invention is shown in a side view in FIG. 3 and in a plan view in FIG. 4.

As shown in FIGS. 3 and 4, the boring head 20 of the present invention has all partition walls 28 disposed around the hollow tube 12 at a predetermined angle (120° in FIG. 4). A cylindrical body 21 surrounds the outer peripheral end.
has. A claw 16 is provided on the partition wall 28 so as to protrude in the normal rotation direction indicated by an arrow 22. Also,
The claws 16 may be mounted not only on the partition wall 28 but also on the cylindrical body 21. It is also preferable to provide the claws 16 inside the cylindrical body 21.

A predetermined number of windows 23 are formed in the outer peripheral wall of the cylindrical body 21 in the circumferential direction, and opening/closing doors 24 of a size suitable for the windows are pivoted to these windows by pivot pins 25 so as to be openable and closable. There is. These doors 24 are indicated by arrows 22
When the head rotates in the normal rotation direction shown by , the head is closed to perform excavation, and when the head rotates in the reverse direction, it opens to perform bottom-expanding excavation.

In the boring head of the present invention, the cylindrical body 2
The door provided at 1 performs the function of the enlargement vane 17 described in connection with the prior art.

A second aspect of the boring head of the present invention includes:
FIG. 5 shows a side view, and FIG. 6 shows a plan view.

The difference between the boring heads of the first and second aspects of the present invention described above is that bypass passages 26 are provided from the water passage through holes 11 of the hollow pipe 12 in correspondence to the number of windows 23. At the point.

The bypass path 26 is the through hole 1 of the hollow pipe 12 during excavation.
During water flow in Step 1, water is poured through the bypass path 26 toward the window 23 on which soil and other substances have adhered, as shown by the arrow 27, and the door 24 is securely closed to ensure efficient excavation. This is to ensure smooth removal of the rod or screw.

Further, this is to ensure that the door 24 is opened during bottom-expanding excavation.

Various constituent parts of the boring head according to the first and second aspects of the present invention explained above will be explained.

(a) Cylindrical body As shown in Fig. 7, when the length of the cylindrical body 21 is L, the diameter is R, and the wall thickness is T, L≧R/10...(1) R/10≧T≧ R/100...(2). If these conditions are not met, the cylindrical body will be damaged or destroyed during excavation, rendering the head useless.

Further, the number of windows 23 provided in the cylindrical body 21 and the number of doors 24 attached thereto are arbitrary, but the angle at which the windows 23 and doors 24 are arranged on the cylindrical body 21 is from the reverse direction to the excavation direction, that is, from the horizontal direction. Let the downward tilt angle α be 0≦α≦45°. In this angle range, the door can be opened and closed reliably during forward and reverse rotations, and bottom-expanding excavation can be performed satisfactorily and efficiently using the door when it is open.

(b) Partition wall inside the cylindrical body In order to fix the hollow cylindrical body 21 to the hollow tube 12, the partition wall 28 arranged between the cylindrical body 21 and the hollow tube 12 has the first and second aspects. 4 and 6, a plurality of straight plates are provided from the upper end to the lower end of the hollow cylindrical body 21. In FIG. However, the partition wall 28 does not have to be a straight plate like this, but may be a curved plate twisted spirally from the upper end to the lower end of the cylindrical body. The twist angle may be any value.

(c) Pawls on bulkhead and cylindrical body The pawls provided on the bulkhead 28 and/or the cylindrical body 21 for excavation, as shown in FIG. Let β be the angle between 0<β≦45°. If the angle is within this range, excavation can be performed satisfactorily.

<Operation of the Invention> The boring head of the present invention is used by being attached to the tip of a boring machine such as a commonly used earth auger.

While rotating the head 20 in the normal rotation direction, the hollow tube 1
The cylindrical body 21 is formed by digging into the soil while injecting a fluid such as water or air through the through hole 11 of No. 2.
And/or the claws 16 and tip blade 14 provided on the partition wall 28 dig the soil, the soil enters the cylindrical body and is removed by an auger or the like, and the head is buried in the soil.

During this forward rotation excavation, the window 2 provided in the cylindrical body 21
The door 24 of No. 3 is housed within the window 23 of the cylindrical body 21, and a hole having the diameter of the cylindrical body is drilled. When the excavation progresses and reaches the supporting layer, the head 20 is reversed and window 2 is opened.
The door 24 opens from 3 and comes out, and bottom expansion excavation is performed. Here, in the head 20 of the present invention, the angle β of the claw 6 from the vertical direction to the normal rotation direction is 0.
Since they are arranged on the partition wall 28 and/or the cylindrical body 21 so that <β≦45°, excavation can be performed satisfactorily. Moreover, the window 23 and the door 24
However, the downward tilt angle α from the horizontal direction is 0≦β≦
Since it is arranged on the cylindrical body 21 so that the angle is 45°, the door can be opened and closed reliably during forward and reverse rotation, and
The square bottom excavation is carried out well and efficiently by the door when opened.

In order to smoothly insert and remove the door from the window 23, pressurized fluid such as water or air is sprayed from the bypass passage 26 of the hollow tube 12 toward the window 23.

In this way, when excavating using the head of the present invention, since the head of the present invention has a cylindrical body around the periphery, this cylindrical body acts as a lateral deviation prevention body, and the hole in the soil is Even as the depth of the hole increases, it does not deviate from the center line of the target hole, making it possible to drill a hole with high centering accuracy.

Further, the cylindrical body disposed in the head of the present invention is
When the length of the cylindrical body is L, the diameter is R, and the wall thickness is T, it has the following configurations: L≧R/10 and R/10≧T≧R/100, so it is extremely sturdy and suitable for drilling. Since the claw (blade tip) is also on a cylindrical body and excavates, even if it hits the old base or rock, it will shatter them, so it is possible to prevent horizontal vibration caused by these and to drill holes with high centering accuracy. can.

In addition, the head of the present invention allows for highly accurate continuous column drilling in which the next hole is drilled one after another, partially overlapping the drilled hole, because of the high drilling accuracy. However, this has traditionally been difficult.

<Effects of the Invention> When excavating using the head of the present invention, since the head of the present invention has a cylindrical body around the periphery, this cylindrical body acts as a lateral deviation prevention body and prevents the soil from moving underground. Even if the depth of the hole increases, it will not deviate from the center line of the target hole, and a hole with high centering accuracy can be drilled.

In addition, the cylindrical body of the head of the present invention is extremely sturdy, and the digging claws (cutting edges) are also placed on the cylindrical body for digging, so even if it hits the old base or bedrock, it will shatter them. Therefore, it is possible to prevent lateral wobbling caused by these and to drill a hole with high centering accuracy.

In addition, the head of the present invention allows for highly accurate continuous column drilling in which the next hole is drilled one after another, partially overlapping the drilled hole, because of the high drilling accuracy. However, this has traditionally been difficult.

[Brief explanation of the drawing]

1 and 2 are side views of a conventional boring head. 3 and 4 are side and top views, respectively, of a first embodiment of the boring head of the present invention. Figures 5 and 6 are side and plan views, respectively, of a second embodiment of the boring head of the present invention. FIGS. 7 and 8 are diagrams for explaining the cylindrical body and the claws, respectively. Explanation of symbols, 10...Conventional head, 11...
Through hole, 12...Hollow pipe, 13...Control valve, 14
... Tip blade, 15 ... Wings, 16 ... Claw, 17 ...
Enlarged blade, 20... Head of the present invention, 21... Cylindrical body, 22... Normal rotation direction, 23... Window, 24...
Door, 25... Pivot pin, 26... Bypass path, 2
7... Water injection direction, 28... Bulkhead.

Claims (1)

[Claims] 1. A hollow tube having a through hole for water passage, a hollow cylindrical body disposed concentrically with the hollow tube, and a structure for fixing the cylindrical body to the hollow tube. a plurality of partition walls installed between the hollow tube and the cylindrical body;
a plurality of claws provided on the cylindrical body and/or the partition wall so as to protrude in the excavation direction; and at least one window formed on the peripheral wall of the cylindrical body;
This window has a door attached so as to close when the head is rotated in the digging (normal rotation) direction and open when the head is rotated in the reverse direction, and the length of the cylindrical body is L and the diameter is R. , when the wall thickness is T, L≧R/10 R/10≧T≧R/100, and when the inclination angle of the window provided in the cylindrical body from the reverse direction to the excavation direction is α, 0≦ α≦
45°, and 0≦β≦45°, where β is an inclination angle from the excavation direction to the normal rotation direction of the claws provided on the cylindrical body and/or the partition wall. 2. A hollow tube having a through hole for water passage, a hollow cylindrical body disposed concentrically with the hollow tube, and the hollow tube fixed to the hollow tube. a plurality of partition walls arranged between the cylindrical body;
a plurality of claws provided on the cylindrical body and/or the partition wall so as to protrude in the excavation direction; and at least one window formed on the peripheral wall of the cylindrical body;
Inside this window is a door that is attached to close when the head is rotated in the drilling (forward rotation) direction and to open when it is rotated in the reverse direction, and a door that communicates with the through hole of the hollow tube and faces the window. and a bypass path formed on the peripheral wall of the hollow tube so as to inject water, and where L is the length of the cylindrical body, R is the diameter, and T is the wall thickness, L≧R/10 R/ 10≧T≧R/100, and when α is the inclination angle of the window provided in the cylindrical body from the reversing direction to the excavation direction, 0≦α≦
45°, and 0≦β≦45°, where β is an inclination angle in the normal rotation direction from the excavation method of the claws provided on the cylindrical body and/or the partition wall.