JP3233183B2 - Drilling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a drilling device used for installing an earth anchor.

[0002]

2. Description of the Related Art Conventionally, an earth anchor method has been widely used for the purpose of preventing falling of a retaining wall or a pier, prevention of buoyancy of a dock floor plate and prevention of ground slippage.

In this earth anchor method, the ground is drilled with a drill bit at the tip of the casing pipe while pouring water is injected into a casing pipe connected to a drilling machine, and an anchor cable (steel) is inserted into the drilled anchor hole. After inserting the grout material into the anchor hole, the casing tube is pulled out and an anchor body is formed in the ground to connect the ground and the structure. The pipes are connected sequentially according to the drilling depth.

[0004] Conventionally, when an earth anchor is constructed on soft ground, a kronen bit has been widely used as one of disposable bits. As shown in FIG. 13, the kronen bit 1 is mounted on the casing tube 3 via a drive shoe 5 screwed to the insertion-side end of the casing tube 3, and the tubular portion 1 a inserted into the drive shoe 5 and the drive And a head 1b arranged at the tip of the shoe 5. Then, while inserting the cylindrical portion 1a into the drive shoe 5, the notch 7 provided at the rear end of the head 1b is engaged with the notch 9 at the tip of the drive shoe 5 in the axial direction (hole drilling direction). By connecting to the drive shoe 5, the rotation of the casing tube 3 is transmitted to the kronen bit 1 during drilling.

When the casing tube 3 is pulled out while pouring the grout material, the kronen bit 1 is separated from the drive shoe 5 and is left in the anchor hole, and is buried by the grout material. In the figure, reference numeral 11 denotes a hole for drilling water.

As another connection structure between the disposable bit and the drive shoe, as shown in FIG. 14 and FIG.
And pin insertion holes 1 provided in the peripheral wall of drive shoe 17 respectively
A method is also known in which the pins 23 are inserted through the pins 9 and 21 to connect the inner bit 15 to the drive shoe 17. In FIG. 14, reference numeral 25 denotes an O-ring which seals between the tip inner bit 15 and the drive shoe 17;
Is an outer bit connected to the tip of the drive shoe 17, and 29 in FIG. 15 is an inner casing described later.

[0007]

By the way, when a drill bit hits hard rock during drilling of the ground, or when the casing pipe is tightened along with the drilling like a gravel layer or a tight sand layer. In this case, the casing tube is flushed to give a hitting force to the drill bit,
It is necessary to excavate the ground while eliminating the slime on the outer periphery of the casing pipe by the flushing operation of the casing pipe.

However, in the connection structure of the kronen bit 1 and the drive shoe 5 shown in FIG. 13, the kronen bit 1 is detached from the drive shoe 5 by flushing the casing tube 3 and once detached. It is difficult to connect the Kronen bit 1 to the drive shoe 5 and a connection structure between the Kronen bit and the drive shoe that can perform a flushing operation has been desired.

On the other hand, in the connection structure shown in FIGS. 14 and 15, since the tip inner bit 15 is connected to the drive shoe 17 via the pin 23, the casing tube can be flushed.

However, in such a conventional example, when the casing tube is pulled out after drilling, a plurality of inner casings 29 are sequentially screwed from the ground as shown in FIG. After the insertion, the striking force is applied to the pin 23 to cut the pin 23 to release the connection between the tip inner bit 15 and the drive shoe 17. Was pointed out.

The O-ring 25 may be displaced toward the lower end of the inner bit 15 by the impact of the inner casing 29 that cuts the pin 23.
-If the ring 25 is displaced to the lower end side, when the ground 13 is a water layer to be pressurized, water or sand flows into the drive shoe 17 or the casing pipe from the pin insertion hole 19 and hinders the construction of the ground anchor. There was also a problem that did.

The present invention has been devised in view of the above circumstances, and enables a flushing operation of a casing pipe at the time of drilling an anchor hole, and a detachment between a drill bit and a drive shoe at the time of pulling out a casing pipe. Provided is a drilling device for earth anchor construction, which can be easily performed and, of course, does not cause water or sand to flow into a drive shoe or a casing pipe even if the ground is a pressurized water layer. The purpose is to do.

[0013]

In order to achieve the above object, a drilling device according to the present invention is screwed to a tip of a casing tube connected to a drilling machine, and a pin engaging groove is formed on an inner periphery thereof. A formed drive shoe, a drill bit in which a plurality of pin insertion holes are formed in a peripheral wall of a cylindrical portion which is meshed with the drive shoe in the axial direction and is connected to the tip thereof, and is inserted into the drive shoe; A bit connecting jig disposed in the bit and having a mounting pin that can be inserted into and disengaged from the pin insertion hole to be disengaged from the pin engaging groove, and a bit connecting jig that is inserted into the casing pipe so as to be able to move up and down to collect the bit connecting jig. A bit connection jig recovery jig, wherein the bit connection jig is mounted in a pantograph shape on a shaft screw rod in which a nut having a locking groove on the center outer periphery is screwed to one end side, Bending and stretching by rotating the nut A plurality of pairs of arms for inserting and removing the mounting pins into and from the pin insertion holes of the drive shoe are provided, and the bit connecting jig collecting jig is provided with a nut fitting hole for fitting to a nut of the bit connecting jig, and the nut. And the connection state between the drill bit and the drive shoe is released by rotating the nut by the bit connection jig recovery jig.

[0014]

According to the drilling device of the present invention, if the mounting pin of the bit connecting jig is engaged with the pin engaging groove of the drive shoe via the pin insertion hole of the drill bit, the drive shoe is cut. The hole bit is connected.

Therefore, if the drive shoe to which the drilling bit is connected is screwed to the tip of the casing pipe and the ground is drilled while water for drilling is supplied into the casing pipe,
An anchor hole is drilled in the ground. Even when the casing tube is flushed during drilling, the drilling bit does not come off the drive shoe because the mounting pin is engaged with the pin engaging groove via the pin insertion hole.

After the drilling is completed, a bit connecting jig collecting jig is inserted into the casing tube, the nut of the bit connecting jig is fitted into the nut fitting hole, and the locking claw is locked by the nut. When the nut is rotated with the bit connection jig collection jig while locking it in the groove, the arm is displaced, the mounting pin retreats from the pin insertion hole, and the connection state between the drill bit and the drive shoe is released. .

Since the locking claw of the bit connecting jig collecting jig is locked in the locking groove of the nut of the bit connecting jig, the bit is released after the connection between the drill bit and the drive shoe is released. If the connecting jig collection jig is raised, the bit connecting jig is simultaneously raised and collected on the ground.

Thereafter, if the casing tube is pulled out while inserting the anchor tension material into the anchor hole and injecting the grout material under pressure, the drill bit is separated from the drive shoe and left in the anchor hole. It will be buried in the anchor hole by the grout material.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of a drilling device according to the present invention. In the drawing, reference numeral 31 denotes a drive shoe screwed to the tip of a casing tube, as in the conventional case, and a single pin engagement A groove 33 is formed. A drill bit 35 is axially meshed and connected to the tip.

The drill bit 35 comprises a head 35a disposed at the tip of the drive shoe 31 and a cylindrical portion 35b inserted into the drive shoe 31.
a is provided with a plurality of holes 37 for drilling water W, and a square pin insertion hole 39 corresponding to the pin engagement groove 33 is formed on the peripheral wall of the cylindrical portion 35b at an interval of 180 °. It is provided open. In the tubular portion 35b, a check valve 41 similar to the conventional one is mounted on the back side of the head 35a.

That is, in FIG. 1, reference numeral 43 denotes a valve seat provided at the center with a water supply passage 45 expanding downward in a tapered shape, and the valve seat 43 is fixed to the inner periphery of the cylindrical portion 35b. I have. Then, a ball valve 49 urged by a spring 47 stretched between the back surface of the head 35a and the valve seat 43 abuts the valve seat 43 to close the water supply passage 45, and the drilling water W is injected into the casing pipe. Then, as shown by the two-dot chain line, the ball pressure 49 moves downward against the spring force of the spring 47 by the water pressure, and the water supply passage 45 is opened. In the drawing, reference numeral 51 denotes an O-ring for sealing a gap between the drive shoe 31 and the drill bit 35.

A bit connecting jig 53 for connecting the drill bit 35 and the drive shoe 31 is disposed above the check valve 41. The bit connecting jig 53 has one shaft screw rod 55 inserted and arranged in the drill bit 35 with the same central axis as the drive shoe 31. A nut 59 having a locking groove 57 on the center outer periphery is screwed to one end thereof, and the shaft screw bar 55 is axially moved by rotating the nut 59 (in the direction of arrows A and B in the figure). ).

Brackets 65 and 6 are provided between the weight 63 mounted on the tip of the shaft screw rod 55 and the nut 59.
7, the pair of arms 69 and 71 are connected in a pantograph shape at an interval of 180 ° and a nut 59.
The arms 69 and 71 bend and extend as shown in FIGS. 1 and 2 due to the movement of the shaft screw rod 55 by the turning operation of.

That is, as shown in FIG. 1, when the nut 59 is rotated in the direction of arrow C, the shaft screw rod 55 moves in the direction of arrow B to narrow the space between the brackets 65 and 67, and connects the arms 69 and 71. The portion 73 is displaced so as to protrude in the direction of the peripheral wall of the drill bit 35 (directions of arrows D and E). The connecting portion 73 has a mounting pin 75 having a square cross section.
When the connecting portion 73 of each of the arms 69 and 71 is displaced in the directions of the arrows D and E by the rotation operation of the nut 59 in the direction of the arrow C, each of the mounting pins 75 is The drive shoe 31 is inserted through the insertion hole 39.
And the drill bit 35 is connected to the drive shoe 33 via the bit connecting jig 53.

When the nut 59 is turned in the direction of arrow F in this state, the shaft screw bar 55 moves in the direction of arrow A as shown in FIG. , 71 are extended, as a result, the mounting pin 75 is retracted from the pin insertion hole 39, and the connection state between the drill bit 35 and the drive shoe 31 is released.

The bit connecting jig 53 for connecting the drill bit 35 and the drive shoe 31 is recovered from the drill bit 35 by the bit connecting jig recovery jig 77 shown in FIG.

FIG. 3 is a sectional view of the bit connecting jig collecting jig 77, and FIG. 4 is a sectional view taken along the line IV-IV of FIG. A hexagonal column-shaped jig body in which a nut fitting hole 81 is formed on the tip side,
A locking member 85 having a locking claw 83 protruding inward at a distal end thereof is provided on a peripheral wall of a substantially intermediate portion of the nut fitting hole 81.
It is movably mounted by a mounting shaft 87 in the direction of the arrow at 180 ° intervals. Then, the locking member 8
A rubber ring 89 is attached to the outer periphery of the jig body 79 so as to correspond to the attachment portion of the nut 5. When the nut 59 is fitted into the nut fitting hole 81 as shown in FIG. The abutting locking member 85 moves outward about the mounting shaft 87 as a center of rotation against the elastic force of the rubber ring 89 as shown by the two-dot chain line, and then the locking groove 5 of the nut 59.
7 passes, the elastic force of the rubber ring 89 returns to the position shown by the solid line, and the locking claw 83
7.

A mounting hole 93 provided in the upper part of the jig main body 79 through the nut fitting hole 81 and the partition wall 91 has a P
One end of the C steel wire 95 is attached by an epoxy adhesive 97, and when the PC steel wire 95 is rotated from the ground in the direction of arrow F to rotate the jig body 79 in the same direction, the PC steel wire 95 is inserted into the nut fitting hole 81. The fitted nut 59 rotates in the direction of arrow F in conjunction with this.

Therefore, when the drill bit 35 is connected to the drive shoe 31 via the mounting pin 75 as shown in FIG. 1, the nut 59 is rotated in the direction of arrow F by the bit connecting jig recovery jig 77 in this manner. Then, as described above, the mounting pin 7
5 is retracted from the pin insertion hole 39 to release the engagement with the pin engagement groove 33, and as shown in FIG. 5, when the bit connecting jig collecting jig 77 is raised, the bit connecting jig collecting jig is recovered. Since the locking claw 83 of the tool 77 is locked in the locking groove 57 of the nut 59, the bit connecting jig 53 is collected on the ground by the bit connecting jig collecting jig 77.

1, reference numeral 99 denotes a notch formed at the rear end of the head 35a of the drill bit 35, as in the conventional example shown in FIG. By engaging the notches 99 and 101 in the axial direction (drilling direction) at the notch, the rotation of the casing tube is transmitted to the drill bit 35.

Since the drilling device according to the present embodiment is configured as described above, in order to construct an earth anchor using the drilling device, first, as shown in FIG. Notch 99 and Notch 1 of Drive Shoe 31
01 is engaged in the axial direction, and the mounting pin 75 of the bit connecting jig 53 is engaged with the pin engaging groove 33 of the drive shoe 31 through the pin insertion hole 39 of the drill bit 35. Thus, the drill bit 35 is connected to the drive shoe 31.

Then, as shown in FIG. 6, the drive shoe 31 is screwed onto the tip of the casing tube 103 connected to the drilling machine, and the drilling water W is supplied into the casing tube 103 as in the conventional case. , The casing pipe 103 according to the drilling depth
And the anchor hole 107 may be drilled in the ground 105 by sequentially connecting the mounting pins 75. At this time, even if the casing 107 tube is flushed, the mounting pin 75 is in contact with the pin engaging groove 33 through the pin insertion hole 39. Since it is engaged, the drill bit 35 does not come off the drive shoe 31. Since the mounting pin 75 having a square cross section is inserted through the pin insertion hole 39 formed in a square shape, the drill bit 35 and the bit connecting jig 53 do not swing during drilling.

The drilling water W is supplied to the water supply passage 4 of the valve seat 43.
5, the water is ejected into the ground 105 from the ejection hole 37 of the drill bit 35, but when the water supply is stopped, the ball valve 49 closes the water supply passage 45 of the valve seat 43 due to the underground water pressure and the spring force of the spring 47. This prevents the backflow of the muddy water into the drill bit 35.

After the drilling is completed, the nut 59 is inserted into the nut fitting hole 81 as shown in FIG. 8 while the bit connecting jig collecting jig 77 is inserted into the casing tube 103 from the ground as shown in FIG. The engaging claw 83 of the engaging member 85 is engaged with the engaging groove 57 of the nut 59 by fitting.

In this state, the PC steel wire 9 from the ground is
5 is rotated in the direction of arrow F.
9 is rotated in the direction of arrow F, the mounting pin 75 is retracted from the pin insertion hole 39 and disengaged from the pin engaging groove 33 as shown in FIGS. If the connecting jig recovery jig 77 is gradually pulled upward, FIG.
As shown in FIG. 10, the entire bit connecting jig 53 is pulled upward and collected on the ground.

Thereafter, as shown in FIG. 11, an anchor tension member 109 is inserted into the casing tube 103, and while grout material G is injected under pressure, the casing tube 10 as shown in FIG.
When the drill bit 3 is pulled upward, the drill bit 35 separates from the drive shoe 31 and remains in the anchor hole 107, and is buried in the anchor hole 107 by the grout material G.

As described above, the drilling apparatus according to this embodiment is
At the time of drilling the ground 105, the mounting pin 75 of the bit connecting jig 53 is engaged with the pin engaging groove 33 through the pin insertion hole 39 to connect the drive shoe 31 and the drill bit 35, and after drilling is completed. , Nut 5 by the bit connecting jig recovery jig 77
The connecting pin 75 is retracted from the pin insertion hole 39 by the rotation operation 9 to release the connection state between the drive shoe 31 and the drill bit 35, and the bit connecting jig 53 is collected by the bit connecting jig collecting jig 77. By using such a drilling device for the construction of an earth anchor, the casing tube 103 can be flushed at the time of drilling, and the drilling bit 35 and the drive shoe 31 can be connected when the casing tube 103 is pulled out. Easy withdrawal,
As a result, the workability of the earth anchor is dramatically improved as compared with the conventional example shown in FIGS.

According to this embodiment, even if the ground 105 is a water layer to be pressurized, the drive shoe 31 and the drill bit 3
When releasing the connection state with the fifth, there is no possibility that water, sand, or the like flows into the drive shoe 31 or the casing tube 103.

In the above embodiment, the brackets 65, 67
The arms 69 and 71 addressed to a pair are connected in a pantograph shape with a 180 ° interval therebetween. For example, the arms 69 and 71 addressed to a pair are connected in a pantograph shape with a 90 ° interval and the connection portion is formed. Attachment pins 75 are attached to the 73, and the cylindrical portion 35 of the drill bit 35 is
b may be provided with four pin insertion holes 39. In this case, the pin insertion holes 39 may be circular small holes.
5 also needs a circular cross section.

In the above-described embodiment, the present invention has been described using the drill bit 35 having the check valve 41 built in the cylindrical portion 35b. Valve 41
Needless to say, the present invention can be applied to a disposable bit having no.

[0041]

As described above, the use of the drilling device according to the present invention for the construction of the earth anchor enables the flushing operation of the casing pipe at the time of drilling the ground and the drilling at the time of pulling out the casing pipe. Since the hole bit and the drive shoe can be easily separated from each other, the workability of the ground anchor has been dramatically improved as compared with the related art.

According to the present invention, when the connection between the drive shoe and the drill bit is released, water and sand flow into the drive shoe and the casing pipe even if the ground is a pressurized water layer. There is no fear.

[Brief description of the drawings]

FIG. 1 is a sectional view of a drilling device according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of the drilling machine showing a state in which the connection state between the drilling bit and the drive shoe has been released by rotating the bit connecting jig collecting jig.

FIG. 3 is a sectional view of a bit connecting jig collecting jig.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a cross-sectional view of the drilling device showing a state where the bit connecting jig is pulled up by the bit connecting jig collecting jig.

FIG. 6 is a schematic diagram showing a state of drilling of the ground by the drilling device shown in FIG. 1;

FIG. 7 is a schematic view showing a state where a bit connecting jig collecting jig is inserted into a casing tube.

FIG. 8 is a schematic view showing a state in which a locking claw of a bit connecting jig collecting jig is locked in a locking groove of a nut of the bit connecting jig.

FIG. 9 is a schematic view showing a state in which the connection state between the drill bit and the drive shoe has been released by rotating the bit connection jig collection jig.

FIG. 10 is a schematic diagram showing a state in which the bit connecting jig is being collected by the bit connecting jig collecting jig.

FIG. 11 is a schematic diagram showing a state in which a grout material is injected under pressure after insertion of an anchor tension material.

FIG. 12 is a schematic view showing a state in which a casing tube has been pulled out.

FIG. 13 is a perspective view of a conventional kronen bit, a drive shoe, and a casing tube.

FIG. 14 is a cross-sectional view showing a conventional method of connecting a drive shoe and a tip inner bit by a pin.

FIG. 15 is a cross-sectional view showing a method of releasing a connection state between the drive shoe and the tip inner bit by a pin.

[Explanation of symbols]

 Reference Signs List 31 drive shoe 33 pin engaging groove 35 drill bit 35a head 35b cylindrical portion 37 ejection hole 39 pin insertion hole 41 check valve 53 bit connecting jig 55 shaft screw rod 57 locking groove 59 nut 65, 67 bracket 69 , 71 arm 75 mounting pin 77 bit connecting jig recovery jig 79 jig main body 81 nut fitting hole 83 locking claw 85 locking member 89 rubber ring 95 PC steel wire 103 casing pipe 105 ground 107 anchor hole

──────────────────────────────────────────────────続 き Continuing on the front page (72) Masakazu Fujita 6-22, Matsugaeda-cho, Kita-ku, Osaka-shi, Osaka Japan Basic Technology Co., Ltd. (72) Masanobu Mai Matsugae-cho, Kita-ku, Osaka, Osaka No. 6-22 Inside Japan Basic Technology Co., Ltd. (56) References JP-A-7-238541 (JP, A) JP-A-7-166545 (JP, A) JP-A-7-3787 (JP, A) JP-A-6-306859 (JP, A) JP-A-4-261996 (JP, A) JP-A-58-165089 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02D 5 / 80 E21B 7/20 E21B 7/00 E21B 10/62

Claims (1)

(57) [Claims] 1. A drive shoe screwed to a tip of a casing tube connected to a drilling machine and having a pin engagement groove formed on an inner periphery thereof, meshed with the drive shoe in the axial direction and connected to the tip. A drill bit having a plurality of pin insertion holes formed in a peripheral wall of a cylindrical portion to be inserted into the drive shoe; and a drill bit disposed in the drill bit, being inserted into and removed from the pin insertion hole to engage and disengage with the pin engagement groove. A bit connecting jig having a flexible mounting pin; and a bit connecting jig recovering jig which is inserted into the casing tube so as to be able to move up and down and collects the bit connecting jig. A nut having a locking groove is screwed to one end of a shaft screw rod, and the shaft screw rod is mounted on the shaft screw rod in a pantograph shape, and the mounting pin is inserted into the pin insertion hole of the drive shoe by bending and extending movement by rotating the nut. Multiple pairs In addition to the arm, the bit connecting jig recovery jig has a nut fitting hole that fits into a nut of the bit connecting jig, and a locking claw that locks in a locking groove of the nut. A drilling device characterized in that a connection state between a drilling bit and a drive shoe is released by a rotation operation of a nut by a jig collecting jig.