JP4001346B2 - Drilling device - Google Patents

Description

  The present invention relates to a drilling device used when, for example, a drilling hole is formed in a preceding ground where a tunnel is to be excavated in a ground reinforcement method such as a tunnel tip receiving method, and at the same time a reinforcing pipe is inserted into the hole. About. More specifically, it is a so-called double-pipe type drilling device in which drilling is performed in a state where an insertion tube is disposed around a hollow tubular drilling rod having a drilling bit at the tip, When a fiber-reinforced resin pipe such as a GFRP pipe is used and the insertion pipe is pulled into the drilling hole while drilling with the drilling bit, and then the insertion pipe is left in the ground as a ground reinforcement pipe. The present invention relates to a particularly effective drilling device.

  Conventionally, for example, when a hole is drilled in a preceding ground where a tunnel is to be excavated in a ground reinforcement method such as a tunnel tip receiving method, and at the same time a reinforcing pipe is inserted into the hole, a hole is drilled at the tip. So-called double-pipe drilling device (double-pipe drilling system) that drills holes in the state where an insertion tube for constituting the reinforcing tube is arranged around a hollow tubular drilling rod having a working bit Various proposals have been made.

The following Patent Documents 1 and 2 show an example of the above-described drilling device. Patent Document 1 describes that only the inner pipe, the inner bit, and the ring bit are rotated by the rotary hitting device of the excavator through the adapter. The insertion tube ( outer tube) does not rotate, and the striking force is transmitted from the inner tube to the inner bit and from the striking surface to the inner step of the ring bit via the adapter. Thus, the insertion tube can be drilled without applying rotational force or striking force.

  Patent Document 2 discloses a large-diameter portion (corresponding to the ring bit) whose outer peripheral portion is circular as a drill bit, and a small-diameter portion (corresponding to the inner bit) protruding forward from the center of the large-diameter portion. A cylindrical guide member attached to the tip of the drilling rod and the tip bit are fitted to each other so that the tip bit has a striking force and a rotational force. The thrust is transmitted so that the insertion tube can be drilled without applying rotation or striking force.

  However, in the drilling device of Patent Document 1, the striking force transmitted to the inner pipe should only act on the inner bit and the ring bit and not on the insertion pipe. When the bedrock is changed from hard to soft, the so-called so-called blanking state occurs, and the striking force does not act much on the ring bit part and is originally provided for pushing the insertion tube. It acts on the step portion of the insertion tube from the insertion tube pulling surface of the joint portion, and as a result, a strong striking force is transmitted to the insertion tube.

  Further, in the drilling device of Patent Document 2, the pipe pressing convex portion of the guide member pushes the inward protruding portion of the pipe leader attached to the distal end of the insertion tube, and the pipe (insertion tube) is drawn into the drilling hole. Therefore, similarly to the above-mentioned Patent Document 1, the guide member strikes the pipe leader when it is idle, and the striking force is transmitted to the insertion tube.

  Therefore, in any of Patent Documents 1 and 2, an impact force is applied to the insertion tube due to blanking during drilling, and as a result, a large tensile force acts on the threaded portion of the insertion tube. In such a double-pipe type drilling device, the threaded part of the insertion pipe drills the rock mass even if sufficient strength is ensured to “draw” or “push” into the location where the drilling has already been performed. Therefore, if the threaded part breaks without being able to withstand the striking force, further extension drilling cannot be performed.

JP-A-7-243295 JP 2001-32664 A

  The present invention has been proposed in view of the above-mentioned problems, and it is possible to perform a good drilling so that the impact force is not applied to the insertion tube as much as possible at the time of drilling, and at the same time to insert the insertion tube into the drilling hole. An object of the present invention is to provide a drilling device that can be used.

In order to achieve the above object, a drilling device according to the present invention has the following configuration. That is, a rotational impact force is applied to the drilling bit provided on the tip side of the drilling rod to drill the hole in the ground, and at the same time, the insertion tube is inserted into the drilling hole as the drilling bit advances. A hole drilling device that is sequentially pulled in, wherein a casing shoe is integrally connected to a distal end portion of the insertion tube, and a buffer cylinder is provided between the casing shoe and the hole drilling bit. The cylindrical body, the drill bit and the casing shoe are connected to each other via a ridge and a groove to which the groove is fitted, and the width of each groove is formed larger than the width of the ridge. Thus, the buffer cylinder, the drill bit and the casing shoe can be moved relative to each other in the axial direction within the range of the difference .

With the above configuration, during drilling operation, by moving relative to the axial direction with respect to each of the cushioning cylinder body a casing shoe provided at the tip portion of the insertion tube and drilling bit, drilling rod buffers the striking force transmitted from the striking force transmitted to the insertion tube Ru are as much as possible reduced. As a result, even when a fiber reinforced resin such as FRP or other resin pipe is used as the insertion pipe, and when the resin pipe is connected by a plurality of couplers or the like and the strength of the screw portion is low, The applied load is reduced and it is durable. In addition, the impact force during drilling mainly acts on the drilling bit or the buffer cylinder, and only acts indirectly on the insertion pipe via the buffer cylinder and the casing shoe. It is possible to reduce the number, and the durability and reliability of the insertion tube can be further increased.

  Hereinafter, the present invention will be specifically described based on the embodiments shown in the drawings. FIG. 1A is a partially enlarged longitudinal sectional view showing an embodiment of a drilling device according to the present invention, and FIG. 1B is a longitudinal sectional view further enlarging a drill bit portion.

  In the figure, B is a drill bit, and the drill bit B of this embodiment is composed of an inner bit 1 and a ring bit 2, and the ring bit 2 is detachably provided on the outer periphery of the inner bit 1. ing. Between the inner bit 1 and the ring bit 2, a concave and convex engaging portion (which is engaged with each other when the inner bit 1 is rotated with respect to the ring bit 2 in a predetermined direction (rotating direction during drilling)) ( (Not shown) is provided, and when the inner bit 1 is rotated in the direction opposite to the above, the engagement state of the concavo-convex engaging portion is released, and when the inner bit 1 is moved to the right in FIG. The ring bit 2 can be pulled out.

  The inner bit 1 is formed in a substantially cylindrical shape, and is formed by connecting a hollow tubular drilling rod 3 to the inner bit 1. In the case of the figure, the outer bit 1 b of the inner hole 1 a of the inner bit 1 has an outer periphery. It is the structure which screwed the drilling rod 3 which has a spiral groove in the surface. A flushing water discharge hole 1c is provided at the front end of the inner hole 1a, and the inner bit 1 extends from the discharge hole 1c through the drilling rod 3 and the inner hole 1a from a water supply source omitted in the drawing when drilling. The flushing water is discharged diagonally forward.

  Around the inner bit 1, there are a plurality of slime discharge passages 1d for discharging slime generated during drilling together with the flushing water, substantially parallel to the axial direction of the inner bit 1 and in the circumferential direction of the inner bit 1. Three cases are provided. In the figure, 1e is a drainage hole provided obliquely and rearwardly from the inner hole 1a toward the slime discharge passage 1d, and 1f and 2f are cutting projections provided on the inner bit 1 and the ring bit 2.

  An insertion tube 4 is provided around the drill rod 3, and a casing shoe 5 is integrally connected to an end of the insertion tube 4 by screw connection or the like. Between the casing shoe 5 and the ring bit 2, there is provided a buffer cylinder 6 for connecting the two, and at both ends and the central part on the inner peripheral surface side of the buffer cylinder 6, there is a radial direction. Inwardly projecting ridges 6a, 6b, 6c are provided. The ridges 6a and 6b at both ends are fitted into the recessed grooves 2a and 5a formed on the outer peripheral surfaces of the ring bit 2 and the casing shoe 5, and the ridge 6c at the center is always connected to the ring bit 2 and the casing shoe 5. It is comprised so that it may be located between.

  In the above configuration, when drilling a rock or the like and embedding the insertion tube in the drilling hole, for example, the following procedure may be performed. That is, the ring bit 2 is connected in advance to the casing shoe 5 attached to the tip of the insertion tube 4 via the buffer cylinder 6. And while connecting the drilling rod 3 to the said inner bit 1, the drilling rod 3 is inserted in an insertion pipe, and the ring bit 2 and the inner bit 1 are engaged.

In this state, as shown in FIG. 3 (a), the rear end portion of the drilling rod 3 is connected to a rotary impacting device 8 such as a drifter provided on the guide shell 7 of the drill jumbo via a shank sleeve 9 or the like. The rotation and striking force of the rotary striking device 8 are transmitted to the inner bit 1 and the ring bit 2 through the drilling rod 3. At the same time, water is supplied from the water supply source (not shown) into the drilling rod 3 through the shank sleeve 9 and the like, so that flushing water is ejected from the discharge hole 1c of the inner bit 1 to the front of the bit 1. Drill a hole in the wall surface W of the bedrock.

  At that time, the inner bit 1 and the ring bit 2 are lubricated and cooled simultaneously by the flushing water, and the rock mass and the like are cut by the rotation and striking force of both the bits 1 and 2. The slime generated by the cutting flows into the space between the drilling rod 3 and the insertion tube 4 from the slime discharge passage 1d formed in the inner bit 1 by fluidizing with the flushing water, and then opening the rear end thereof. Is discharged to the outside.

  While the hole is drilled as described above, the insertion tube 4 is inserted into the hole through the buffer cylinder 6 and the casing shoe 5 as the ring bit 2 moving together with the inner bit 1 moves forward. In this case, the ring bit 2 is free to rotate with respect to the insertion tube 4, so that the ring bit 2 is rotated, but the insertion tube 4 is almost rotated by frictional contact with the hole wall. It will be pulled in without.

  Further, the striking force of the rotary striking device 8 is transmitted to the inner bit 1 through the drilling rod 3, and the base portion of the inner bit 1 hits the end face of the ring bit 2 and is transmitted exclusively to the ring bit 1. However, the ring bit 1 is robustly formed for drilling the rock, and is not screwed with other members, so there is no problem even if it is hit.

  Further, at the time of drilling, the insertion tube 4 is pulled by the ring bit 2 to the front side in the drilling direction through the buffer cylinder 6 and the casing shoe 5 as described above. The ring bit 2 is constantly subjected to a force to vibrate in the axial direction by the impact of the rotary impacting device 8 and the reaction force received when the bit surface provided with the cutting projections 1f and 2f is struck against the rock. As shown in FIG. 1 (b), the ring bit 2, the buffer cylinder 6 and the casing shoe 5 are in the most extended state in the axial direction as shown in FIG. At this time, the insertion tube 4 is pulled forward via the buffer cylinder 6 and the casing shoe 5, but at the next moment, the bit surface receives a strong reaction force from the rock cutting surface. Therefore, at the moment when the force at the time of impact by the rotary impacting device 8 is released, as shown in FIG. 2A, the ring bit 2, the buffer cylinder 6, the casing shoe 5, and the insertion tube 4 connected thereto. Are in the state closest to the axial direction.

  Next, when there is a blow again, the ring bit 2 moves forward from the state shown in FIG. 2 (a) to the state shown in FIG. 2 (b). By pulling the buffer cylinder 6, the state shown in FIG. 1B (the state in which the insertion tube 4 is pulled) is obtained. In this repetitive operation, the ring bit 2 and the buffer cylinder 6 are relatively movable in this example by about 1 cm, and the buffer cylinder 6 and the casing shoe 5 or the insertion tube 4 are relatively movable in this example by about 1 cm. Therefore, in the meantime, that is, in this example, in the moving range of 2 cm in total, no axial force acts on the insertion tube 4. Therefore, the impact force and impact acting on the buffer cylinder 6 and the insertion tube 4 via the ring bit 2 can be gradually reduced or absorbed, so that the impact on the insertion tube 4 can be reduced as much as possible. Can do.

  In addition, when the pressing force from the rock surface suddenly hits a soft rock suddenly, the drilling rod 3 hits the inner bit 1 and the ring bit 2 unnecessarily strongly from the state shown in FIG. In this case, the impact force is once absorbed by the shock absorbing cylinder 6 without directly acting on the insertion tube 4 via the casing shoe 5, Transmission of the striking force to the insertion tube 4 is reduced as much as possible.

  In addition, it is good to provide the propulsion auxiliary means 20 as shown in FIG.3 (b) and (c) between the rear-end part of the said insertion pipe 4, and the shank sleeve 9, and in the case of a figure, the propulsion auxiliary means 20 is shown. As shown, a cylindrical propulsion body 21 provided with a slime discharge hole 21 a is provided so as to be movable forward with the forward movement of the rotary impacting device 8. That is, the rotary impacting device 8 is mounted on the bed 22 in such a manner that the drilling rod 3 can move forward relative to the guide shell 7 by the amount advanced by the drilling. In this example, A frame 24 having a disk body 23 for supporting the propulsion body 21 is fixed with bolts 25. The disc body 23 is formed with a ridge 23a that can be fitted to the inner diameter of the propulsion body 21, and the propulsion body 21 is fitted to the ridge 23a during the drilling operation.

  On the other hand, a cylindrical member 26 having the same diameter as that of the insertion tube 4 is connected to the rear end portion of the insertion tube 4 by the coupler 14 for connection of the insertion tube using the coupler connection screw at the rearmost end. The cylindrical member 26 is provided with a spring member 27. And both are connected so that the said propulsion body 21 can press the insertion tube 4 via the spring member 27. FIG. Then, the impact force of the rotary impacting device 8 is not transmitted to the insertion tube 4, and the insertion tube 4 is pushed forward through the propelling body 21 by the amount of advancement of the rotational impacting device 8 by the drilling hole. As a result, the propulsion operation of the insertion tube 4 becomes smoother. It should be noted that vibration due to the striking operation of the rotary striking device 8 is inevitably transmitted to the frame 24 via the bed 22, but in this example, the propulsion body 21 is inserted through the spring member 27 into the insertion tube. By pressing 4 forward, it is possible to prevent this striking force from being transmitted to the insertion tube 4.

  As described above, drilling is performed sequentially while reducing or buffering the impact force or impact acting on the insertion tube 4, and at that time, the drilling rod 3 and the insertion tube 4 are respectively set as necessary. Then add the couplers 13 and 14 etc. Then, when the hole is drilled to a predetermined depth, the drilling rod 3 and the inner bit 1 are pulled out from the hole. In this embodiment, the inner bit 1 is rotated together with the drilling rod 3 in the direction opposite to that at the time of drilling. After releasing the engagement of the concavo-convex engaging portion, the inner bit 1 may be pulled out to the opening side of the drilling hole together with the drilling rod 3. As a result, the inner bit 1 and the drill rod 3 can be withdrawn and collected from the drilling hole and reused while the ring bit 2, the casing shoe 5 and the insertion tube 4 remain in the drilling hole.

  After pulling out and removing the inner bit 1 and the drilling rod 3 as described above, for example, in a ground reinforcement method such as tunnel tip receiving, the insertion pipe 4 remaining in the drilling hole is used. As the insertion pipe, for example, a steel pipe, a vinyl chloride pipe or a fiber reinforced resin pipe having a plurality of discharge holes formed in the peripheral wall is used as the insertion pipe. Also, as described above, the insertion tube is sequentially connected (joint) at the time of drilling, and is placed in a natural ground at a predetermined elevation angle, and the plurality of connected insertion tubes are used as reinforcement tubes and are inserted into the reinforcement tube. An injection tube or an inner tube is accommodated to inject a consolidated material, and a fixed region or a consolidated region is formed in the reinforcing tube and the surrounding natural ground to reinforce the natural ground. The plurality of connected insertion pipes can be used as a drain pipe.

  In the above-described embodiment, the ring bit 2 and the casing shoe 5 are connected by the buffer cylinder 6, and the ring bit 2 is moved forward during the drilling operation via the buffer cylinder 6 and the casing shoe 5. Although the insertion tube 4 is drawn into the hole, the buffer cylinder 6 is connected to the inner bit 1 and the casing shoe 5 so that the buffer cylinder 6 is moved forward by the inner bit 1 when drilling. Alternatively, the insertion tube 4 may be drawn into the hole through the casing shoe 5.

  Moreover, although the said embodiment used what consists of the inner bit 1 and the ring bit 2 as the bit B for drilling, the thing of various structures is applicable not only to this but FIG. 4 shows the example It is. FIGS. 7A to 7C each use a tip bit in which the inner bit 1 and the ring bit 2 are integrated, and will be described below in order.

  In FIG. 4A, a bit adapter 11 is connected to the tip of the drilling rod 3 by screw connection or the like, and an inner and outer integrated tip bit 12 is provided at the front portion of the bit adapter 11. At the time of drilling, the bit adapter 11 engages with the tip bit 12 and rotates integrally. When the bit adapter 11 is drilled with the drill rod 3 after being drilled, it is easily separated from the tip bit 12 and collected. can do.

  In this example, the tip bit 12 and the casing shoe 5 attached to the insertion tube 4 are connected by a buffer cylinder 6, and the protrusions 6a and 6b provided at both ends of the buffer cylinder 6 are By engaging the groove grooves 12a and 5a formed in the tip bit 12 and the casing shoe 5, respectively, the groove grooves 12a and 5a are formed to have a width larger than the width of the protrusions 6a and 6b. Within the range of the difference, the tip bit 12, the casing shoe 5 and the buffer cylinder 6 are relatively movable in the axial direction.

  The bit adapter 11 is provided with a protrusion 11d, and the buffer cylinder 6 is provided with a step portion 6d with which the protrusion 11d is engaged. When the projection 11d is moved forward, the projection 11d abuts against the stepped portion 6d, the buffer cylinder 6 moves forward, and the insertion tube 4 is pulled into the drilling hole via the casing shoe 5 in conjunction therewith. . When drilling, the bit adapter 11 and the tip bit 12 are configured to be able to move slightly relative to each other in the axial direction. Other configurations are substantially the same as those in the above embodiment. In the figure, 11a is a central hole of the bit adapter 11, 11c is a slime discharge passage, 12c is a flushing water discharge hole, and 12f is a cutting projection.

  In the above configuration, at the time of drilling, the tip bit 12, the casing shoe 5 and the buffer cylinder 6 can be moved relative to each other in the axial direction within the range of the width difference, and the bit adapter 11 and the tip bit 12 When an impact force is applied, the striking force can be reduced or absorbed in substantially the same manner as in the above embodiment by moving relative to each other within the above range.

  Next, FIG. 4B is a view except that the front surface of the tip bit 12 is formed to be substantially flat and the direction of the protrusion 6b of the buffer cylinder 6 and the groove 5a of the casing shoe 5 are opposite to each other. 4 (a) is substantially the same as FIG. 4 (a), and FIG. 4 (c) shows a projection between the bit adapter 11 and the tip bit 12 instead of providing the projection 11d and step 6d on the bit adapter 11 and the buffer cylinder 6. A portion 11e and a recess 12e are provided, and at the time of drilling, when the bit adapter 11 moves forward along with the drilling rod 3, the tip bit 12 also advances in the same direction, and in conjunction therewith, the buffer cylinder 6 and the casing shoe In this configuration, an insertion pipe (not shown) connected thereto is drawn into the drilling hole. Structures other than those described above are the same as those in the above-described embodiment in both cases of FIGS.

  As described above, in the hole drilling device according to the present invention, the buffer cylinder is provided between the drill bit and the insertion pipe, and the buffer cylinder is predetermined in the axial direction with respect to each of the bit and the insertion pipe. It is possible to reduce as much as possible that the striking force during drilling is transmitted to the insertion tube by a very simple configuration that can be relatively moved by a distance. For example, a fiber reinforced resin such as a GFRP tube as the insertion tube. Even when using pipes, and especially when inserting a plurality of resin pipes by connecting them sequentially with a coupler, it is possible to securely insert even a relatively low-strength screw part without damaging it. A hole drilling device with good characteristics can be provided.

(A) is the longitudinal cross-sectional view which expanded one part which shows one Embodiment of the drilling apparatus by this invention, The same figure (b) is the longitudinal cross-sectional view which expanded the bit part for drilling further. (A) And (b) is an expanded longitudinal cross-sectional view which shows the operation state of the said drilling apparatus. (A)-(c) is explanatory drawing of a drilling state. (A)-(c) is an expanded longitudinal cross-sectional view of another drilling apparatus.

Explanation of symbols

B Drilling Bit 1 Inner Bit 2 Ring Bit 2a Concave Groove 3 Drilling Rod 4 Insertion Pipe 5 Casing Shoe 5a Concave Groove 6 Buffer Cylinder 6a-6c Projection 7 Guide Shell 8 Rotating Hammer 9 Shank Sleeve 11 Bit adapter 12 Tip bit 20 Propulsion auxiliary means 21 Propulsion body

Claims (6)

A rotary striking force is applied to the drilling bit provided on the tip side of the drilling rod to make a hole in the ground, and at the same time, the insertion tube is sequentially drawn into the drilling hole as the drilling bit advances. A drilling device configured as described above,
A casing shoe is integrally connected to the distal end portion of the insertion tube, and a buffer cylinder is provided between the casing shoe and the drill bit, and the buffer cylinder, the drill bit, and the casing shoe are provided. Are connected to each other through a ridge and a groove groove into which the ridge is fitted, and the width of each groove is larger than the width of the ridge, so that the above-mentioned buffer is within the range of the difference. A drilling device, wherein the cylindrical body, the drilling bit, and the casing shoe are configured to be relatively movable in the axial direction . The drilling bit is made from the inner bit and ring bit or tip-bit, and drilling time, the ring from the inner bit or bit adapter was attached to the distal end of the drilling rod bits or tips bits and the buffer accommodating cylinder The drilling device according to claim 1, wherein the insertion tube is drawn into the drilling hole through a casing shoe . The drill bit includes an inner bit and a ring bit or a tip bit, and when drilling, an inner bit or a bit adapter attached to a tip portion of the drill rod through the buffer cylinder and the casing shoe. The drilling device according to claim 1, wherein the insertion tube is drawn into the drilling hole.   A propulsion auxiliary means is provided between the rear end portion of the insertion tube and the rotary impacting device to which the drilling rod is connected, and is capable of pressing the insertion tube forward as the rotary impacting device moves forward. Item 4. The hole drilling device according to any one of Items 1 to 3.   The insertion pipe is made of a steel pipe or a fiber reinforced resin pipe having a plurality of discharge holes drilled in the peripheral wall, and the insertion pipe is sequentially connected to the natural ground at a predetermined elevation angle while being connected. A natural ground reinforcement in which a plurality of insertion pipes are used as reinforcement pipes, and an injection pipe or an inner pipe is inserted into the pipe to inject a consolidated material, thereby forming a fixing region or a consolidation region in the natural ground around the reinforcement pipe. The drilling device according to any one of claims 1 to 4, wherein the drilling device is used for a construction method.   The insertion pipe is composed of a vinyl chloride pipe or a fiber reinforced resin pipe having a plurality of discharge holes drilled in a peripheral wall, and the insertion pipe is sequentially connected to a natural mountain at a predetermined elevation angle and connected. The drilling device according to any one of claims 1 to 4, wherein the plurality of inserted tubes are used as drainage tubes.

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