JP2019044509A - Bit attaching/detaching device - Google Patents

Abstract

To enable smooth separation of a bit from a boring rod.SOLUTION: A bit attaching/detaching device comprises a latch case 4 having a bit 3 attached to its end and provided with a rotatable latch pawl 8, a packer tube 20 including a packer 22 and inserted into a boring rod 6 together with a water conduit in communication with the water conduit for taking out the spring water, a latch release member 30 attached to the packer tube 20 and inserted into the latch case 4 to rotate the latch pawl 8 in a disengaging direction, a coupling latch 34 for coupling the latch case 4 and the latch release member 30 by inserting the latch release member 30 into the latch case 4, and a release pin 39 for rotating the coupling latch 34 in the disengaging direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a bit detaching apparatus for removing a bit for excavation by being used in an apparatus for measuring spring pressure by taking out spring water in the ground from a drilling 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 groundwater characteristics, a test hole is excavated in the ground and the pressure of spring water in the test hole is measured.

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

Based on the above assumptions, conventional measurements of spring water are carried out according to the following procedure.
First, a bit for excavating the ground is attached to the tip of the boring rod, and an excavation hole is excavated while adding the boring rod. When there is spring water in the drilling hole, all of the drilling tools including the boring rod and bit are removed from the drilling hole and collected. After that, a casing for protecting the hole wall is inserted to the front of the spring point, and a packer is inserted into the casing. The packer is expanded at the position where the packer comes out of the casing in front of the spring point to block the excavation hole, and the spring water is taken from the deeper side than the packer and the pressure of the spring is measured.

Japanese Patent No. 5155661

The above-mentioned conventional procedure requires many work processes, including drilling holes, removing and collecting drilling tools, inserting casings into the drilling holes, and inserting packers. It becomes. For example, when the excavation hole becomes long, such as 100 m, the labor and time of the work greatly increase as the excavation length increases.
In order to improve work efficiency and to accurately measure the measured values when the drilling hole is long, the packer is inserted to the predetermined depth of the drilling hole (spring water generation point) with the drilling tools left in the drilling hole. A method has been developed in which the excavation hole is blocked by inflating, and in this state, the spring water is taken out from the back side of the excavation hole packer and the pressure is measured.

  However, in this case, since the bit for excavation is attached to the tip of the boring rod, the bit interferes with the insertion of the packer. For this reason, it is necessary to remove 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 a conventional problem, and when inserting the packer into the excavation hole, the bit can be smoothly separated from the boring rod, thereby reducing the work process. An object of the present invention is to provide a bit attaching / detaching device that can be simplified and can be used efficiently, and can be used repeatedly.

  In the bit attaching / detaching device of the present invention, a bit provided on the tip side of the boring rod excavates a drilling hole, the drilling hole is blocked by the packer expanded in the drilling hole, and the spring water is taken out from the drilling hole and the water pressure is increased. A bit attaching / detaching device used in a measuring device, wherein the bit is attached to a tip, and a latch claw capable of rotating is provided inside, and a latch case attached to a tip side of the boring rod by engagement of the latch claw And a packer tube that is attached to the tip of the water conduit and is inserted into the boring rod together with the water conduit in a state of communication with the water conduit that takes out the spring water, and is attached to the tip of the packer tube, 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. And a coupling latch for coupling the latch case and the latch release member by engaging the latch case by inserting the latch release member into the latch case, and being introduced into the latch release member through the packer tube and the coupling And a release pin that rotates the latch in the anti-engagement direction.

In the present invention, the latch pawl is connected to the boring rod via a stopper rod attached to the tip of the boring rod, and a receiving recess is formed on the stopper rod so that the latch pawl is detachably engaged. .
The release pin is introduced into the latch release member by fluid pressure.

According to the present invention, the latch release member rotates the latch pawl in the anti-engagement direction with the insertion of the packer tube, so that the bit of the latch case can be smoothly separated from the boring rod, and the bit removal work process Reduction, simplification, and work efficiency.
Further, since the coupling latch provided on the latch release member brings the latch case and the latch release member into a coupled state, the latch case provided with the bit can be smoothly connected to the boring rod, and the bit is connected to the boring rod. It can be easily mounted on the tip side. This enables repeated use.

(A) is sectional drawing which shows the excavation state by a bit, (b) is sectional drawing which shows the state before inserting a latch release member following (a). 1 shows a state following FIG. 1, in which (a) is a cross-sectional view of a state where a latch release member is inserted, and (b) is a cross-sectional view of a state where the connection between the bit and the boring rod is released. FIG. 3 shows a state following FIG. 2, in which (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. FIG. 3A is a cross-sectional view of a state where the latch release member is retracted, and FIG. 3B is a cross-sectional view of the subsequent state.

  1 to 4 are cross-sectional views showing the structure and operation of the bit attaching / detaching device 1 according to one embodiment of the present invention in the order of steps. The excavation tools are configured by connecting 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 the excavation hole 2 (in this embodiment, a horizontal hole) in the ground 7 and is connected to the tip 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 feed force and a rotational force are transmitted from the drill head to the boring rod 6. As a result, the bit 3 excavates the ground 7. At the time of excavation, drilling water is supplied to the water swivel. The drilling water is poured from the tip of the bit 3 toward the drilling hole 2 through the inside of the boring rod 6. The discharged drilling water passes between the boring rod 6 and the hole wall of the drilling hole 2 and is discharged to the ground.

  The bit 3 is provided with a plurality of tips (not shown) for crushing the ground 7 at the tip, and a plurality of water discharge holes (not shown) for pouring drill water from the water swivel. Inside the bit 3, a check valve 16 biased in the closing direction by a spring is arranged. The check valve 16 is opened by the supply pressure of the drilling water from the water swivel, and closes when the supply of the drilling water is stopped. This prevents backflow of drilling water and spring water to the boring rod 6.

  The latch case 4 is formed of a horizontally long cylinder, and the bit 3 is attached to the front end side in the length direction by screw connection, and the stopper rod 5 is attached to the rear end side by spline connection. Since the latch case 4 rotates together with the stopper rod 5 by 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 transmitting the rotational force, other than spline coupling, for example, a structure in which the latch case 4 and the stopper rod 5 are fitted in a non-circular cross section such as a hexagonal cross section may be used.

  A latch claw 8 is attached to the inside of the latch case 4 so as to protrude. The latch claw 8 is attached to a shaft body 11 crossing the latch case 4 so as to be rotatable 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 a corner portion on the stopper rod 5 side is a claw portion 8 a that is engaged with the stopper rod 5. When the claw portion 8a (latch claw 8) is engaged with the stopper rod 5, the latch case 4 and the stopper rod 5 are coupled to each other and 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. In order to engage the latch rod 8 with the stopper rod 5, a biasing member 12 made of a spring is disposed between the latch plate 8 and the latch case 4.

The stopper rod 5 is formed of a horizontally long cylinder and is provided between the latch case 4 and the boring rod 6. The stopper rod 5 is formed by coaxially extending a stopper main body portion 5a on the latch case 4 side and a connecting portion 5b on the boring rod 6 side. A spline for coupling the latch case 4 is formed in the stopper body 5a.
The connecting portion 5 b 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 screw connection or uneven fitting or non-circular cross-section fitting. Thereby, the stopper rod 5 is fed and rotated integrally with the boring rod 6.

  A recessed receiving recess 14 is formed at 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 detachable. Since the stopper rod 5 and the latch case 4 are coupled 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 coupled via the stopper rod 5.

  The bit detaching apparatus 1 includes a packer tube 20 and a latch release member 30 in addition to the above excavation tools.

The packer tube 20 has a water conduit 21 extending in the axial direction and a packer 22 disposed outside the water conduit 21. The rear end portion of the packer tube 20 is connected to a water conduit (not shown) made of a double tube rod. The water pipe 21 becomes a passage of spring water by communicating with the inner pipe of the water guide pipe. The packer 22 is formed in a tubular shape extending in the axial direction by a flexible rubber material. Both end portions in the length direction of the packer 22 are held on the outer surface of the water pipe 21, but between the both ends are the expansion portions 23 that face the water pipe 2 with a gap.
Such a packer tube 20 is used by being connected to the water conduit formed by the double tube rod described above. When a fluid such as compressed air or water is supplied to the outer tube of the water conduit, the water conduit 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 contact of the packer 20, the excavation hole 2 is divided at the packer 20 (see FIG. 2B).

  The latch release member 30 is a member that releases the connection 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 has a structure in which the release portion 31, the coupling portion 32, and the connection bracket portion 33 are successively connected from the latch case 4 side, and the whole can enter the stopper rod 5. It is possible.

  The release portion 31 is formed in 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 (disengagement direction) with the stopper rod 5. As a result, the engagement between the latch case 4 and the stopper rod is released.

  The coupling portion 32 is formed by a shaft that is somewhat larger in diameter than the release 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 biased so as to protrude 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 release member 30 and the latch case 4 are coupled by the coupling latch 34 engaging the coupling recess 37. Accordingly, when the latch release member 30 is retracted, the latch case 4 (see FIG. 2B) that has advanced forward from the stopper rod 5 is retracted. By this retreat, the latch case 4 enters the stopper rod 5 (see FIG. 3A).

  A pin hole 38 is formed in the coupling 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 passage 21 of the packer tube 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 by this rotation, the latch release member 30 and the latch case 4 are coupled. Is released.

  The connection bracket portion 33 is a member that is connected to the packer tube 20 when the tip of the water flow tube 21 of the packer tube 20 is inserted. A plurality of water guide holes 40 are formed radially in the connection bracket portion 33. The spring water is led from the water guide hole 40 to the water pipe 21 of the packer pipe 20. The spring water passes through the inner pipe of the water guide pipe from the packer pipe 20 and is taken out of the system and used for pressure measurement.

Next, the operation of this embodiment will be described in the order of work steps.
FIG. 1A shows a state where the excavation tool 2 excavates the excavation hole 2 in the lateral direction with respect to the ground 7. 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. In this state, the boring rod 6 is advanced and rotated while the boring rod 6 is added, whereby excavation force is transmitted to the bit 3 through the stopper rod 5 and the latch case 4 to perform excavation.

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

As shown in FIG. 2A, the insertion of the packer tube 20 causes the latch release member 30 to enter the stopper rod 5, and the release portion 31 rotates the latch claw 8 in the anti-engagement direction. The engagement with the receiving recess 14 is released. As a result, the connection between the latch case 4 and the stopper rod 5 is released.
At this time, since 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, the latch case 4 and the latch release member 30 are coupled.

Thereafter, by further advancing the packer tube 20, as shown in FIG. 2B, the latch case 4 and the packer tube 20 are moved from the stopper rod 5 into the excavation hole 2 with the stopper rod 5 remaining at the position T. It comes out. In this state, the expansion part 23 of the packer 22 is expanded like a chain line with a fluid such as water or compressed air. Since the expansion portion 23 of the packer 22 is pressed 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 connection bracket portion 33 of the latch release member 30 and 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 used for water pressure measurement.

  FIG. 3A shows a step after the water pressure measurement. The water guide pipe and the packer pipe 20 made of a double pipe rod are moved backward as indicated by an 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 moves backward 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 made of double pipe rod and the packer pipe 20 by fluid pressure such as pressurized water or compressed air, and the pin hole 38 of the latch release member 30 is passed. To introduce. By reaching the pin hole 38, the release pin 39 rotates the coupling latch 34 in the anti-engagement direction. As a result, the connection between the latch release member 30 and the latch case 4 is released, so that the latch release member 30 can be retracted together with the packer tube 20 and taken out from the excavation hole 2 as indicated by an arrow E in FIG. it can. FIG. 4B shows the subsequent state, in which the latch case 4 provided with the bit 3 in the excavation hole 2 and the stopper rod 5 remain in the excavation hole 2 in a coupled state. Thereby, the subsequent excavation by the boring rod 6 can be performed.

In such an embodiment, the latch release member 30 releases the coupling of the latch pawl 8 by inserting the packer tube 20 into the bore rod 6, so that the bit 3 can be easily removed from the bore rod 6 (stopper rod 5). Can be separated. Thus, the bit 3 can be smoothly inserted into the excavation hole 2 without obstructing the insertion of the packer tube 20.
Further, since the coupling latch 34 brings the latch case 4 and the latch release member 30 into a coupled state, the latch case 4 (bit 3) can be smoothly connected to the stopper rod 5 (boring rod 6). 3 can be easily mounted. For this reason, it can be used repeatedly.

  In the above embodiment, the application to the horizontal excavation hole 2 has been shown, but the present invention is not limited to this, and the same can be applied to the vertical excavation hole and the oblique excavation hole.

DESCRIPTION OF SYMBOLS 1 ... Bit removal | desorption apparatus, 2 ... Drilling hole, 3 ... Bit, 4 ... Latch case, 5 ... Stopper rod, 6 ... Boring rod, 8 ... Latch claw, 14 ... Receiving recessed part, 20 ... Packer pipe, 21 ... Water flow pipe, 22 ... packer, 30 ... latch release member, 34 ... latching latch, 39 ... release pin

Claims (3)

A bit detaching device used in a device for measuring a water pressure by excavating a drilling hole by a bit provided on the tip side of the boring rod, blocking the drilling hole by a packer expanded in the drilling hole, and taking out spring water from the drilling hole Because
A latch case attached to the tip end side of the boring rod by the latch claw that is provided inside the bit and the bit is attached to the tip;
A packer tube provided with the packer and attached to the tip of the water guide tube in communication with a water guide tube for taking out the spring water and inserted into the boring rod together with the water guide tube;
A latch releasing member that is attached to the tip of the packer tube and rotates the latching claw in the anti-engagement direction by being inserted into the latch case;
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 couple the latch case and the latch release member;
A bit attaching / detaching device comprising: a releasing pin that is introduced into the latch releasing member through the packer tube and rotates the coupling latch in the anti-engagement direction.   The latch pawl is connected to the boring rod via a stopper rod attached to the tip of the boring rod, and a receiving recess is formed on the stopper rod so that the latch pawl is detachably engaged. The bit attaching / detaching device according to claim 1.   3. The bit attachment / detachment device according to claim 1, wherein the release pin is introduced into the latch release member by fluid pressure.

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