JP6920690B2 - Bit attachment / detachment device - Google Patents

Description

The present invention relates to a bit attachment / detachment device for attaching / detaching a bit for excavation by using it in an apparatus for measuring spring water pressure by taking out spring water in the ground from an excavation hole excavated in the ground.

Groundwater characteristics such as ground permeability and groundwater level are important information for the design and construction of civil engineering structures such as tunnels and building structures. In order to evaluate the characteristics of this groundwater, a test hole is drilled in the ground and the pressure of the spring water to the test hole is measured.

In Patent Document 1, a packer is attached to the pipe body, the packer is inserted into the hole of the excavation hole as a test hole (hereinafter referred to as the excavation hole), and the packer is expanded in this state to block the hole opening portion of the excavation hole. As a state, a technique is disclosed in which spring water is taken out from an excavation hole and the pressure of the spring water is measured by the taken out spring water.
However, with this structure, spring water cannot be measured when the excavation hole collapses. Further, even if the packer blocks the hole opening portion, there is a problem that the spring water cannot be accurately grasped if the spring water escapes to a fault or the like deeper than the hole opening portion. For this reason, it is preferable to set the insertion position of the packer as the spring water generation location and take out the spring water from the back side of the packer.

Conventional spring water measurement based on the above is performed by the following procedure.
First, a bit for excavating the ground is attached to the tip of the boring rod, and the excavation hole is excavated while adding the boring rod. If there is spring water in the drilling hole, all drilling tools, including the boring rod and bit, will be removed from the drilling hole and recovered. After that, a casing for protecting the hole wall is inserted until just before the spring point, and a packer is inserted into this casing. The packer expands the packer at a position out of the casing in front of the spring point to block the excavation hole, and the spring water is taken out from the deeper part than the packer to measure the pressure of the spring water.

Japanese Patent No. 5155761

Since the conventional procedure described above requires a large number of work steps including excavation of a drilling hole, removal and recovery of a drilling tool, insertion of a casing into a drilling hole, and insertion of a packer, the number of work steps is large and complicated work. It becomes. This causes a large increase in labor and time as the excavation length becomes longer when the excavation hole becomes longer, for example, 100 m or the like.
In order to improve work efficiency and accurately grasp the measured values when the excavation hole is long, insert the packer to the specified depth (spring water generation point) of the excavation hole while leaving the excavation tools in the excavation hole, and insert the packer. A method has been developed in which the excavation hole is blocked by expansion, and in this state, spring water is taken out from the back side of the excavation hole packer to measure the pressure.

However, in this case, since the bit for excavation is attached to the tip of the boring rod, the bit interferes with the packer insertion. Therefore, it is necessary to disconnect the bit from the connection with the boring rod prior to the insertion of the packer or with the insertion of the packer.

The present invention has been made in consideration of such conventional problems, and enables smooth separation of the bit from the boring rod when the packer is inserted into the excavation hole, thereby reducing the work process. It is an object of the present invention to provide a bit attachment / detachment device which enables simplification and work efficiency and can be used repeatedly.

In the bit attachment / detachment device of the present invention, a bit provided on the tip side of the boring rod excavates an excavation hole, the excavation hole is blocked by a packer expanded in the excavation hole, and spring water is taken out from the excavation hole to apply water pressure. A bit attachment / detachment device used for a measuring device, which is a latch case in which the bit is attached to the tip and a rotatable latch claw is provided inside, and is attached to the tip side of the boring rod by engaging the latch claw. And the packer pipe provided with the packer and attached to the tip of the water pipe in a state of being communicated with the water pipe for taking out the spring water and inserted into the boring rod together with the water pipe, and the packer pipe attached to the tip of the packer pipe. A latch release member that rotates the latch claw in the anti-engagement direction by being inserted into the latch case, and a latch release member that is attached to the latch release member and engages with the latch case by inserting the latch release member into the latch case. It is provided with a coupling latch that connects the latch case and the latch release member, and a release pin that is introduced into the latch release member through the packer pipe and rotates the coupling latch in the anti-engagement direction. It is a feature.

In the present invention, the latch claw is connected to the boring rod via a stopper rod attached to the tip of the boring rod, and a receiving recess is formed in the stopper rod so that the latch claw can be engaged with and disengaged. ..
Further, the release pin is introduced into the latch release member by fluid pressure.

According to the present invention, since the latch release member rotates the latch claw in the anti-engagement direction with the insertion of the packer tube, the bit of the latch case can be smoothly separated from the boring rod, and the bit release work process. It is possible to reduce, simplify, and improve work efficiency.
Further, since the coupling latch provided on the latch release member is in a state where the latch case and the latch release member are connected to each other, the latch case provided with the bit can be smoothly connected to the boring rod, and the bit can be connected to the boring rod. It can be easily attached to the tip side. This enables repeated use.

(A) is a cross-sectional view showing a state of excavation by a bit, and (b) is a cross-sectional view showing a state before inserting the latch release member following (a). A state following FIG. 1 is shown, (a) is a cross-sectional view in a state in which the latch release member is inserted, and (b) is a cross-sectional view in a state in which the connection between the bit and the boring rod is released. A state following FIG. 2 is shown, (a) is a cross-sectional view of a state in which the latch case is retracted, and (b) is a cross-sectional view of a state in which a release pin is introduced. A state following FIG. 3 is shown, (a) is a cross-sectional view of a state in which the latch release member is retracted, and (b) is a cross-sectional view of a state after that.

1 to 4 are cross-sectional views showing the structure and operation of the bit attachment / detachment device 1 according to the embodiment of the present invention in the order of processes. The excavation tools are formed by adding the bit 3, the latch case 4, the stopper rod 5, and the boring rod 6 in this order from the front side to the rear side of the excavation hole 2 in the excavation direction.

The bit 3 excavates an excavation hole 2 (in this embodiment, a lateral hole) in the ground 7, and is connected to the tip end side of the boring rod 6. In this embodiment, the bit 3 is attached to the tip of the latch case 4, and the latch case 4 is attached to the tip of the boring rod 6 via the stopper rod 5. As a result, the bit 3 is connected to the tip end side of the boring rod 6 via the latch case 4 and the stopper rod 5.

A water swivel (not shown) is attached to the rear end of the boring rod 6, and a drill head (not shown) is connected to the water swivel, and a feeding force and a rotational force are transmitted from the drill head to the boring rod 6. By doing so, the bit 3 excavates the ground 7. At the time of excavation, excavation water is supplied to the water swivel. The excavated water passes through the inside of the boring rod 6 and is discharged from the tip of the bit 3 toward the excavated hole 2. The discharged excavated water passes between the boring rod 6 and the hole wall of the excavation hole 2 and is discharged to the ground.

A plurality of chips (not shown) for crushing the ground 7 are attached to the tip of the bit 3, and a plurality of spout holes (not shown) for pouring out excavated water from a water swivel are formed. A check valve 16 urged in the closing direction by a spring is arranged inside the bit 3. The check valve 16 opens when the supply pressure of the excavated water from the water swivel is stopped, and closes when the supply of the excavated water is stopped. This prevents the backflow of excavated water and spring water to the boring rod 6.

The latch case 4 is formed of a horizontally long tubular body, and a bit 3 is attached to the front end side in the length direction by screw coupling, and a stopper rod 5 is attached to the rear end side by spline coupling. Since the latch case 4 rotates together with the stopper rod 5 due to the spline coupling, the rotational force of the boring rod 6 is transmitted to the bit 3 at the tip of the latch case 4. For the transmission of the rotational force, a structure other than the spline coupling may be used, and for example, the latch case 4 and the stopper rod 5 may be fitted with a non-circular cross section such as a hexagonal cross section.

The latch claw 8 is attached to the inside of the latch case 4 so as to protrude. The latch claw 8 is rotatably attached to a shaft body 11 that crosses the latch case 4 in the forward and reverse directions. The latch claw 8 is formed in a boat shape extending in the front-rear direction from the shaft body 11, and the corner portion on the stopper rod 5 side is a claw portion 8a that engages with the stopper rod 5. When the claw portion 8a (latch claw 8) engages with the stopper rod 5, the latch case 4 and the stopper rod 5 are coupled to each other, and these can be integrally moved. When the claw portion 8a is disengaged from the stopper rod 5 and the engagement is released, the latch case 4 and the stopper rod 5 can be separated from each other. An urging member 12 made of a spring is arranged between the latch claw 8 and the latch case 4 in order to engage the latch claw 8 with the stopper rod 5.

The stopper rod 5 is formed of a horizontally long tubular body, and is provided between the latch case 4 and the boring rod 6. The stopper rod 5 is formed by coaxially extending the stopper main body portion 5a on the latch case 4 side and the connecting portion 5b on the boring rod 6 side. A spline for connecting the latch case 4 is formed on the stopper main body 5a.
The connecting portion 5b of the stopper rod 5 is inserted into the boring rod 6. The connecting portion 5b and the boring rod 6 are connected by a connecting structure such as a screw connection, a concave-convex fitting, or a non-circular cross-section fitting. As a result, the stopper rod 5 is fed and rotated integrally with the boring rod 6.

A recessed receiving recess 14 is formed in a portion of the stopper rod 5 facing the latch claw 8. The claw portion 8a of the latch claw 8 is engaged with the receiving recess 14 so as to be engageable and disengaged. Since the stopper rod 5 and the latch case 4 are connected by the engagement of the latch claw 8 with the receiving recess 14, the boring rod 6 and the latch case 4 (bit 3) are connected via the stopper rod 5.

The bit attachment / detachment device 1 includes a packer pipe 20 and a latch release member 30 in addition to the above excavation tools.

The packer pipe 20 has a water pipe 21 extending in the axial direction and a packer 22 arranged outside the water pipe 21. The rear end of the packer pipe 20 is connected to a water pipe (not shown) composed of a double pipe rod. The water pipe 21 becomes a spring water passage by communicating with the inner pipe of the water pipe. The packer 22 is formed of a flexible rubber material into a tubular shape extending in the axial direction. Both ends of the packer 22 in the length direction are held on the outer surface of the water pipe 21, but between the both ends is an expansion portion 23 facing the water pipe 2 with a gap.
Such a packer pipe 20 is used by being connected to a water pipe made of the above-mentioned double pipe rod, and when a fluid such as compressed air or water is supplied to the outer pipe of the water pipe, the water pipe 21 and the packer 22 are used. Since the fluid enters between the two, the expansion portion 23 of the packer 20 expands and presses against the hole wall of the excavation hole 2. Since the excavation hole 2 is blocked by the pressure welding of the packer 20, the excavation hole 2 is divided at the packer 20 as a boundary (see FIG. 2B).

The latch release member 30 is a member that releases the coupling between the latch case 4 and the stopper rod 5 by the latch claw 8. The latch release member 30 is attached to the tip of the packer tube 20 so as to be coaxial.

The entire latch release member 30 extends in the axial direction, and the release portion 31, the coupling portion 32, and the connecting bracket portion 33 are continuous in this order from the latch case 4 side, and the entire latch release member 30 can enter the stopper rod 5. It is possible.

The release portion 31 is formed on a tapered small-diameter shaft body. The release portion 31 enters the latch case 4 inside the stopper rod 5 when the latch release member 30 enters the stopper rod 5. Then, it comes into contact with the latch claw 8 attached to the latch case 4 and rotates the latch claw 8 in the anti-engagement direction (engagement disengagement direction) with the stopper rod 5. As a result, the engagement between the latch case 4 and the stopper rod is released.

The connecting portion 32 is formed by a shaft body having a diameter slightly larger than that of the releasing portion 31. A coupling latch 34 is attached to the outside of the coupling portion 32. The coupling latch 34 is rotatably attached to the shaft pin 35, and is urged so as to project outward (to the latch case 4 side) by a torsion spring 36 locked to the shaft pin 35. A coupling recess 37 formed of an annular recess is formed on the inner surface of the latch case 4 so as to face the coupling latch 34. The latch releasing member 30 and the latch case 4 are coupled by engaging the coupling latch 34 with the coupling recess 37. As a result, when the latch release member 30 is retracted, the latch case 4 (see FIG. 2B) that has advanced forward of the stopper rod 5 is retracted. Due to this retreat, the latch case 4 enters the stopper rod 5 (see FIG. 3A).

A pin hole 38 is formed in the joint portion 32. The pin hole 38 is formed so as to communicate with the water pipe 21 of the packer pipe 20, and a part of the coupling latch 34 faces the pin hole 38. A release pin 39 that has passed through the water pipe 21 of the packer pipe 20 due to fluid pressure is introduced into the pin hole 38 (see FIG. 3B). Then, when the release pin 39 is introduced into the pin hole 38 and comes into contact with the coupling latch 34, the coupling latch 34 rotates in the anti-engagement direction, and this rotation causes the latch release member 30 and the latch case 4 to be coupled. Is released.

The connecting bracket portion 33 is a member that is connected to the packer pipe 20 by inserting the tip of the water pipe 21 of the packer pipe 20 into the connecting bracket portion 33. A plurality of water guide holes 40 are radially formed in the connecting bracket portion 33. The spring water is guided from the water guide hole 40 to the water pipe 21 of the packer pipe 20. Then, the spring water passes from the packer pipe 20 through the inner pipe of the water pipe, is taken out of the system, and is used for pressure measurement.

Next, the operation of this embodiment will be described in the order of work processes.
FIG. 1A shows a state in which a lateral excavation hole 2 is excavated with respect to the ground 7 by excavation tools. At the time of excavation, the latch case 4 is connected to the stopper rod 5 by the latch claw 8 engaged with the receiving recess 14. By feeding and rotating the boring rod 6 while adding the boring rod 6 in this state, the excavation force is transmitted to the bit 3 via the stopper rod 5 and the latch case 4 to perform excavation.

When spring water is generated in the excavation hole 2, excavation is stopped, and the excavation tools including the bit 3 are retracted to an appropriate position T where the spring water pressure can be measured while collecting the boring rod 6. Then, the packer pipe 20 is inserted into the boring rod 6 as shown by the arrow B in FIG. 1B while adding a water pipe made of a double pipe rod. Prior to insertion, a latch release member 30 is attached to the tip of the packer tube 20.

By inserting the packer tube 20, as shown in FIG. 2A, the latch release member 30 enters the stopper rod 5, the release portion 31 rotates the latch claw 8 in the anti-engagement direction, and the latch claw 8 is moved. It is disengaged from the engagement with the receiving recess 14. As a result, the connection between the latch case 4 and the stopper rod 5 is released.
At this time, the coupling latch 34 attached to the latch release member 30 enters the coupling recess 37 of the latch case 4 by the spring force of the torsion spring 36, so that the latch case 4 and the latch release member 30 are in a coupled state.

After that, by further advancing the packer pipe 20, as shown in FIG. 2B, the latch case 4 and the packer pipe 20 are moved into the excavation hole 2 from the stopper rod 5 in a state where the stopper rod 5 is left at the position T. It will be in a state of being out. In this state, the expansion portion 23 of the packer 22 is expanded like a chain wire by a fluid such as water or compressed air. Since the expansion portion 23 of the packer 22 presses against the hole wall of the excavation hole 2 due to the expansion, the excavation hole 2 is blocked with the packer 22 as a boundary. The spring water enters the water guide hole 40 formed in the connecting bracket portion 33 of the latch release member 30, is taken out of the system from the water pipe 21 of the packer pipe 20 through the inner pipe of the water pipe, and is used for water pressure measurement.

FIG. 3A shows a step after the water pressure measurement. The water pipe and the packer pipe 20 made of the double pipe rod are retracted as shown by the arrow C. At this time, since the latch case 4 is connected to the packer tube 20 by the coupling latch 34 of the latch release member 30, the latch case 4 retracts in the same direction and enters the stopper rod 5 left at the position T. ..

After that, as shown in FIG. 3B, the release pin 39 is passed through the water guide pipe and the packer pipe 20 made of the double pipe rod by the fluid pressure such as pressure water or compressed air, and the pin hole 38 of the latch release member 30 is passed. Introduce to. Upon reaching the pin hole 38, the release pin 39 rotates the coupling latch 34 in the anti-engagement direction. As a result, the coupling between the latch release member 30 and the latch case 4 is released. Therefore, as shown by the arrow E in FIG. 4A, the latch release member 30 can be retracted together with the packer pipe 20 and taken out from the excavation hole 2. can. FIG. 4B shows the subsequent state, and the latch case 4 having the bit 3 in the excavation hole 2 and the stopper rod 5 are left in the excavation hole 2 in a coupled state. As a result, the subsequent excavation by the boring rod 6 can be performed.

In such an embodiment, by inserting the packer tube 20 into the boring rod 6, the latch releasing member 30 releases the coupling of the latch claws 8, so that the bit 3 can be easily removed from the boring rod 6 (stopper rod 5). Can be separated. As a result, the bit 3 does not interfere with the insertion of the packer pipe 20, and the packer 22 can be smoothly inserted into the excavation hole 2.
Further, since the coupling latch 34 is in a state in which the latch case 4 and the latch release member 30 are coupled to each other, the latch case 4 (bit 3) can be smoothly connected to the stopper rod 5 (boring rod 6), and the bit can be smoothly connected. 3 can be easily attached. Therefore, it can be used repeatedly.

In the above embodiment, the application to the excavation hole 2 in the lateral direction is shown, but the application is not limited to this, and the application can be similarly applied to the excavation hole in the vertical direction and the oblique direction.

1 ... Bit attachment / detachment device, 2 ... Drilling hole, 3 ... Bit, 4 ... Latch case, 5 ... Stopper rod, 6 ... Boring rod, 8 ... Latch claw, 14 ... Receiving recess, 20 ... Packer pipe, 21 ... Water pipe, 22 ... Packer, 30 ... Latch release member, 34 ... Coupling latch, 39 ... Release pin

Claims (3)

A bit detachable device used for a device in which a bit provided on the tip side of a boring rod excavates an excavation hole, the excavation hole is blocked by a packer expanded in the excavation hole, spring water is taken out from the excavation hole, and water pressure is measured. And
A latch case in which the bit is attached to the tip and a rotatable latch claw is provided inside, and the bit is attached to the tip side of the boring rod by engaging the latch claw.
A packer pipe provided with the packer, attached to the tip of the water pipe in a state of communicating with the water pipe for taking out the spring water, and inserted into the boring rod together with the water pipe.
A latch release member attached to the tip of the packer tube and inserted into the latch case to rotate the latch claw in the anti-engagement direction.
A coupling latch that is attached to the latch release member and engages with the latch case by inserting the latch release member into the latch case to connect the latch case and the latch release member.
A bit attachment / detachment device including a release pin that is introduced into the latch release member through the packer tube and rotates the coupling latch in an anti-engagement direction. The latch claw is connected to the boring rod via a stopper rod attached to the tip of the boring rod, and the stopper rod is formed with a receiving recess in which the latch claw is engageable and disengaged. The bit attachment / detachment device according to claim 1. The bit attachment / detachment device according to claim 1 or 2, wherein the release pin is introduced into the latch release member by a fluid pressure.

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