JP2007284972A - Drilling apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drilling apparatus which carries out excavation of sediment by arranging bits on a front end of a hollow cylindrical casing, and rotating the bits together with the casing, and facilitates assembly thereof. <P>SOLUTION: The drilling apparatus is formed of: the cylindrical casing 2; an outer bit 3 which is connected to one end of the casing 2, formed like a cylinder, functions to excavate the sediment via the tip thereof, and has a diameter-contracted portion 15 on the rear thereof; an inner bit 4 loosely fitted in the outer bit 3 and formed like a closed end cylinder; through holes 16, 17 radially penetrated into the diameter-contacted portion 15 and the inner bit 4; a connection block 10 inserted into the through holes 16, 17 to fix the bits to each other; a block retaining member 12 arranged in the inner bit 4 in a manner longitudinally slidable in a predetermined range, for inhibiting inward movement of the connection block 10 when located on the front and canceling the inhibition of the movement when located on the rear; a spring 18 arranged on the connection block 10 in a manner protruding in a radially outward direction; a block retaining collar 19 arranged on the periphery of the diameter-contracted portion 15, for pressing the spring 18 in a contracting direction; and a recovering member 6 for pulling the block retaining member 12 rearward to cancel fixture between the bits, and recovering the inner bit 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a drilling device in which a bit is provided at the tip of a hollow cylindrical casing and the bit is rotated together with the casing to excavate earth and sand, and more particularly to a drilling device capable of collecting a part of the bit. .

  As a hole drilling device, one disclosed in Patent Document 1 is known. As shown in FIG. 16, in this drilling device 40, the bit 42 provided at the tip of the casing 41 is divided into a hollow cylindrical outer bit 43 and an inner bit 44 loosely fitted in the outer bit 43. The outer bit 43 and the inner bit 44 are fixed and used by the lock mechanism 45 when drilling, and the lock mechanism 45 is released after drilling, and the inner bit 44 can be removed from the outer bit 43 and collected. ing. According to this, even if an expensive carbide tip 46 is used for the inner bit 44, the cost can be kept relatively low, and a hard ground can be drilled at low cost.

JP 2006-28767 A Japanese Patent No. 2759437

  By the way, the locking mechanism 45 of the hole drilling device 40 includes a recess 47 provided on the inner peripheral surface of the outer bit 43, a through hole 48 formed through the inner bit 44 in the radial direction, and a through hole 48. A connecting block 49 that penetrates and fits into the recess 47, a compression spring 50 that elastically urges the connecting block 49 radially inward, and a connection block 49 that is provided in the inner bit 44 resists the compression spring 50. Since the block holding member 51 is provided so as to protrude outward in the radial direction, when the inner bit 44 is fixed to the outer bit 43, the positions of the through hole 48 and the concave portion 47 are aligned, and the connecting block 49 needs to be pushed out and inserted into the recess 47 from the through hole 48 side, and the recess 47 is a machine that transmits the rotational driving force to the inner bit 44 via the connecting block 49. Therefore, it is formed in a dimension that hardly generates a gap between the connecting block 49 and the through holes 48 and the recesses 47 cannot be visually confirmed. There was a problem that it took. Specifically, the positions of the through holes 48 and the recesses 47 are aligned in advance, and the inner bit 44 is inserted into the outer bit 43 for alignment. In such a case, a complicated operation is required in which the inner bit 44 is slightly swung while the block holding member 51 is pushed in such a manner that the connecting block 49 protrudes toward the outer bit 43 side, and the concave portion 47 is searched and connected. Further, when drilling a hard ground by applying a striking force to the casing 41, the block presser member 51 is caused to move up and down in the drilling direction by the inertial force due to the striking force, thereby allowing the connecting block 49 to move in the radial direction. As a result, the contact surface with the concave portion 47 is not constant, and there is a problem that the wear becomes intense.

  Accordingly, an object of the present invention is to solve the above-described problems, and to provide a drilling device that can easily fix an inner bit to an outer bit and is easy to assemble.

  In order to solve the above-described problems, the present invention provides a hollow cylindrical casing, a hollow cylindrical shape connected to one end of the casing, excavating earth and sand at the tip, and a reduced diameter portion at the rear in the drilling direction. An outer bit, a bottomed cylindrical inner bit that is loosely fitted into the outer bit and excavates the earth and sand on the inner peripheral side of the outer bit, and the reduced diameter portion and the inner bit penetrate in the radial direction. The formed through-holes, a connecting block that is inserted through the through-holes and fixes the inner bit to the outer bit, and is provided in the inner bit so as to be slidable within a predetermined range in the front-rear direction and at the front position. A block presser member that abuts the connecting block and restricts its movement inward in the radial direction, and releases it from the connecting block when it is moved to the rear position. A spring that protrudes radially outward from the connecting block and expands and contracts in the radial direction; a block presser collar that covers the outer periphery of the reduced diameter portion and compresses the spring radially inward; and the block A recovery member is provided that is mounted on the presser member and pulls the block presser member backward to release the outer bit and the inner bit from being fixed by the connecting block and recover the inner bit.

  Further, by providing the inner bit with a spring for preventing malfunction, which elastically biases the block pressing member forward, the movement of the block pressing member is suppressed, and the contact surface between the connecting block and the outer bit concave portion Can be made constant, and the degree of wear can be reduced.

  The block presser collar may have an inclined surface for guiding the spring radially inward at the front end in the drilling direction.

  The casing is screwed onto the rear end portion of the reduced diameter portion so as to cover the outer peripheral surface thereof, and is fixed with the block presser collar sandwiched between the stepped portion that is enlarged in front of the reduced diameter portion. Configure.

  According to the present invention, the inner bit can be easily fixed to the outer bit and can be easily assembled.

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  As shown in FIGS. 1, 2, and 12, a hole drilling device 1 includes a casing 2 formed in a hollow cylindrical shape, and a hollow cylindrical outer bit 3 connected to one end of the casing 2 for excavating earth and sand. A bottomed cylindrical inner bit 4 that is loosely fitted in the outer bit 3 for excavating the earth and sand on the inner peripheral side of the outer bit 3, and an inner bit 4 for removably fixing the inner bit 4 to the outer bit 3 The lock mechanism 5 includes a recovery member 6 for releasing the lock of the inner bit 4 and the outer bit 3 by the lock mechanism 5 and recovering the inner bit 4 after drilling a desired depth. .

  The casing 2 has a base end portion (rear side) via a swivel (not shown) for supplying high-pressure slime-treated water to a drifter (not shown) which is a rotary percussion type drilling machine, for example, a rotary percussion drill machine. For example, the casing 2 is pushed vertically while being rotated around the axis while standing vertically to the ground. The casing 2 is used by being screwed and connected in series as appropriate according to the depth (length) of the drilling holes.

  As shown in FIGS. 1 and 3, the outer bit 3 has a digging surface 7 at the tip, and is configured to excavate the ground by receiving a rotary impact driving force and an axial pressing force from the casing 2. Yes. The excavation surface 7 of the outer bit 3 is formed to have a diameter larger than that of the casing 2, and a flow path (not shown) for circulating excavated earth and sand between the ground and the casing 2 when the ground is excavated. Z)).

  As shown in FIGS. 1, 4 and 5, the inner bit 4 is coaxially connected to a cutting block 9 which is formed in a substantially cylindrical shape and has a carbide tip 8 at the tip, and a rear end in the excavation direction of the cutting block 9. A cylindrical base 11 fixed to the outer bit 3 via a connecting block 10 which will be described later, and a block pressing member 12 which is detachably provided at the rear end of the base 11 are slidably guided in the axial direction. And a retaining member 13 for restricting the backward movement of the block pressing member 12. The cutting block 9 is formed with a water supply hole 14 for supplying water (slime-treated water) guided through the casing 2 toward the excavated ground, and the excavated earth and sand are formed as slime from the excavated ground to the casing. 2 is carried out to the ground along the outer peripheral surface. As shown in FIG. 8B, the retaining member 13 is formed in a substantially C-shape when viewed from the back, and is attached to the rear end of the inner bit 4 so as to be detachable as a pair. ing.

  As shown in FIGS. 1, 2, and 3, the lock mechanism 5 includes a reduced diameter portion 15 formed by reducing the outer diameter at the rear portion in the drilling direction of the outer bit 3, a reduced diameter portion 15, and an inner bit. Through-holes 16 and 17 formed through the base 11 in the radial direction, a connection block 10 inserted through the through-holes 16 and 17 to fix the inner bit 4 to the outer bit 3, and the inner bit 4 When it is slidable within a predetermined range in the front-rear direction (axial direction) and abuts against the connecting block 10 at the front position to restrict its inward radial movement, and when it is moved to the rear position A block pressing member 12 that is released from the connecting block 10 and releases its movement restriction, a spring 18 that protrudes radially outward from the connecting block 10 and expands and contracts in the radial direction, and covers the outer periphery of the reduced diameter portion 15. Provided It is constituted by a block retaining collar 19 to shrink down the ring 18 radially inward.

  As shown in FIGS. 1 and 3, the reduced diameter portion 15 is formed so that its outer diameter is larger than the inner diameter of the casing 2 and smaller than the outer diameter of the casing 2, and the casing 2 is formed at the rear end portion. And a male threaded portion 20 to be screwed together. Further, O-rings 21 are provided on the inner peripheral surface and the outer peripheral surface of the reduced diameter portion 15 so as to be located in front of and behind the through hole 16, respectively. To prevent it from entering. At the front end of the reduced diameter portion 15, a step portion 22 is formed which is expanded in diameter and connected to the outer peripheral surface of the outer bit 3. The front end of the block presser collar 19 is brought into contact with the step portion 22 to block the block presser. The front end position of the collar 19 is determined.

  As shown in FIGS. 3, 4, and 5, each of the through holes 16 and 17 has a rectangular opening cross section and the same size, and the connecting block 10 formed in a rectangular cross section is extremely small. It comes to be accommodated by play. In addition, a plurality of through holes 16 and 17 are formed in the circumferential direction, specifically, two sets are opposed to each other in the diameter direction, and the outer bit 3 and the inner bit 4 are connected to each other via the connecting block 10 at each position. It can be fixed. The through-holes 16 and 17 may be one set as long as the outer bit 3 and the inner bit 4 can be fixed sufficiently firmly to the extent that they are not supported by the drilling hole. If the strength of the outer bit 3 and the inner bit 4 can be secured sufficiently, There may be a plurality of three or more sets. Further, the through holes 16 and 17 do not have to face the other through holes 16 and 17 in the diameter direction.

  As shown in FIGS. 1 and 2, the connecting block 10 is formed by forming a spring mounting recess 23 in a rectangular parallelepiped metal block, and the through hole 16, 17 with the opening of the recess 23 facing radially outward. It is supposed to be inserted through. The spring 18 is formed of a coil spring, and is formed so that one end side is accommodated in the recess 23 and the other end side protrudes from the connection block 10.

  As shown in FIGS. 1 and 6, the block pressing member 12 is formed in a substantially cylindrical shape, and allows water supplied from the casing 2 side to pass through the water supply hole 14 of the inner bit 4. Further, the block pressing member 12 is formed at the front part and is formed at the center part in the front-rear direction with a substantially conical guide part 24 that gradually allows the connecting block 10 to move inward in the radial direction. A holding part 25 for restricting the movement of the block 10 inward in the radial direction, a slide part 26 formed on the rear part and slidably in contact with the retaining member 13 of the inner bit 4, and a recovery member formed on the inner peripheral surface, which will be described later And a locking portion 27 for locking 6. The presser portion 25 is formed to have an outer diameter that is substantially equal to the inner diameter of the inner bit 4, and abuts against the connecting block 10 when the block presser member 12 is in the front end position within a range in which the block presser member 12 can slide within the inner bit 4. It has become so. The slide part 26 is formed with a smaller diameter than the presser part 25, and a space 28 is formed between the inner part 4 and the inner peripheral surface of the inner bit 4. In this space 28, a malfunction preventing spring 29 that elastically biases the block pressing member 12 forward is accommodated. Specifically, the malfunction preventing spring 29 is formed of a coil spring, and is interposed between the retaining member 13 and the presser part 25 in a state of being compressed in the axial direction, thereby moving the presser part 25 forward in the excavation direction. It is designed to suppress the movement of the block pressing member 12 due to impact or the like. The locking portion 27 is formed by forming an annular protrusion protruding radially inward on the inner periphery of the block pressing member 12.

  The block presser collar 19 is formed of a cylindrical body and has the same outer diameter as the outer bit 3 and the casing 2. The block retainer collar 19 has an inclined surface 30 directed radially inward to guide the spring 18 radially inward at the front end in the drilling direction, and from the rear to the front on the outer periphery of the reduced diameter portion 15 of the outer bit 3. It is configured to push the tip of the spring 18 radially inward along the inclined surface 30 when it is moved and covered. The block retainer collar 19 includes a stepped portion 22 and a casing 2 that are expanded in diameter in front of the reduced diameter portion 15 by screwing the casing 2 into the male thread portion 20 of the reduced diameter portion 15 of the outer bit 3. It is sandwiched between and fixed.

  As shown in FIGS. 12 and 13, the recovery member 6 includes a long material 31 that is inserted into the casing 2 from the ground after completion of drilling, and a block presser member 12 that is provided at the tip of the long material 31. The claw member 32 is fixed to the portion 27. The claw member 32 is fixed to the elongate member 31 and extends in the axial direction, and a plurality of hooking claws 34 provided by being elastically urged by the tip member 33 so as to protrude radially outward. After being inserted into the block pressing member 12, it is pushed inward in the radial direction by coming into contact with the locking portion 27, and moved to the front of the locking portion 27 beyond the locking portion 27. It protrudes outward in the direction, and thereafter, the long material 31 is pulled backward to be hooked on the locking portion 27 and fixed.

  Next, the operation of this embodiment will be described.

  When assembling the hole drilling device 1, first, as shown in FIGS. 7 and 8, the malfunction prevention spring 29 is put on the outer periphery of the slide portion 26 of the block retainer member 12, and the block retainer member 12 and the malfunction prevention spring 29 are provided. Is inserted into the base 11 of the inner bit 4 and a retaining member 13 is attached to the rear end of the base 11. At this time, the retaining member 13 pushes the rear end of the malfunction-preventing spring 29 into the base 11, thereby imparting elastic force to the malfunction-preventing spring 29. As a result, the block pressing member 12 is pressed against the bottom surface of the front inner bit 4 and does not move until it is hit. Further, since the retaining member 13 is formed not in an annular one piece but in a C-shaped two piece, it is not necessary to pass from the rear end side of the block pressing member 12 and can be easily attached to the base 11.

  Next, as shown in FIG. 9, the inner bit 4 to which the block pressing member 12 is attached is inserted into the outer bit 3 and the positions of the through hole 17 of the inner bit 4 and the through hole 16 of the outer bit 3 are aligned. Two through holes 16 and 17 are formed in the outer bit 3 and the inner bit 4 so as to face each other in the diameter direction, and either one of the outer holes 3 is formed in the through hole 17 of the inner bit 4. By overlapping, the other through hole 16 also overlaps the through hole 17 of the inner bit 4. When the through holes 16 and 17 are overlapped in the radial direction in this way, the connecting block 10 is inserted into the through hole 16 of the outer bit 3 from the radially outer side with the spring 18 positioned radially outward. To do. The connecting block 10 passes through the outer bit 3, is then inserted into the through hole 17 of the inner bit 4, passes through the inner bit 4, and comes into contact with the block pressing member 12 to stop the insertion depth. This operation can be performed very easily because it is only an operation of inserting the connecting block 10 into the exposed through hole 16.

  Thereafter, as shown in FIG. 10, while pushing the spring 18 into the connecting block 10, the outer periphery of the reduced diameter portion 15 of the outer bit 3 is covered with a block presser collar 19, and the outer periphery of the through hole 16 is covered in a liquid-tight manner. A radial elastic force is applied to the spring 18. At this time, since an inclined surface 30 facing radially inward is formed at the front end of the block presser collar 19, the radially outward protruding end of the spring 18 is guided radially inward along the inclined surface 30. And can be easily pushed into the connecting block 10. The connecting block 10 receives the elastic force of the spring 18 and is pressed against the block pressing member 12.

  And as shown in FIG. 11, the hole drilling apparatus 1 is completed by screwing and connecting the front-end | tip of the casing 2 with the rear end of the outer bit 3. As shown in FIG.

  In the drilling operation, the casing 2 is set up vertically with respect to the ground, the outer bit 3 and the inner bit 4 are put on the ground, water is pumped into the casing 2 and the rear end of the casing 2 is lowered with a rotary percussion drill machine. Rotate while pushing. At this time, the block presser member 12 is restrained from moving upward (rearward) by its own weight and is urged forward by the malfunction preventing spring 29, so that it does not move rearward due to impact or the like. 3 and the inner bit 4 are not unlocked by mistake.

  When the hole formed by the drilling device 1 reaches a desired depth, the driving of the drilling device 1 is stopped and the inner bit 4 is recovered.

  As shown in FIG. 12, the collection work of the inner bit 4 is performed by attaching the collection member 6 to the block pressing member 12 and pulling the collection member 6 backward. Specifically, as shown in FIG. 13, first, the recovery member 6 is inserted into the casing 2 from the ground with the claw member 32 as a tip, and the claw member 32 is inserted into the block presser member 12. When the claw member 32 is inserted into the block pressing member 12, the hooking claw 34 of the claw member 32 hits the locking portion 27 of the inner bit 4 and is moved radially inward so as to escape from the locking portion 27. . As shown in FIG. 14, when the hooking claw 34 passes over the locking portion 27, the hooking claw 34 projects again outward in the radial direction and is hooked on the locking portion 27. Thereafter, the block pressing member 12 can be pulled up by pulling the collection member 6 from the ground. As shown in FIG. 15, when the collecting member 6 is pulled backward, the block pressing member 12 moves toward the rear position in the inner bit 4 while pressing and contracting the malfunction preventing spring 29. Since the conical guide part 24 is formed in the front part of the block pressing member 12, the connecting block 10 is gradually moved radially inward along the inclination of the guide part 24, and the entire block pressing member 12 is When the connection block 10 is moved to the rear of the through-hole 17, the restriction of movement inward in the radial direction is completely released and jumps into the inner bit 4. Thereby, each connection block 10 detaches | leaves from the through-holes 16 and 17, and the lock | rock of the outer bit 3 and the inner bit 4 is cancelled | released. Then, when the block pressing member 12 is further pulled rearward, the inner bit 4 is pulled rearward through the malfunction preventing spring 29 and is pulled backward together with the block pressing member 12 and the malfunction preventing spring 29 to be recovered. Is done. Further, the connecting block 10 that has entered the inner bit 4 is also collected.

  Thus, the hollow cylindrical casing 2 and the outer bit 3 connected to one end of the casing 2 and formed into a hollow cylindrical shape, excavating earth and sand at the tip, and having the reduced diameter portion 15 at the rear portion in the drilling direction. And a bottomed cylindrical inner bit 4 that is loosely fitted in the outer bit 3 and excavates the earth and sand on the inner peripheral side of the outer bit 3, and a reduced diameter portion 15 and the inner bit 4 are formed to penetrate in the radial direction. Through-holes 16 and 17, a connecting block 10 that is inserted through the through-holes 16 and 17 to fix the inner bit 4 to the outer bit 3, and is provided in the inner bit 4 so as to be slidable within a predetermined range in the front-rear direction. This is a block that abuts against the connecting block 10 at the front position and restricts the radially inward movement thereof, and separates from the connecting block 10 and releases the movement restriction when moved to the rear position. The hook holding member 12, a spring 18 that protrudes radially outward from the connecting block 10, and expands and contracts in the radial direction, and is provided on the outer periphery of the reduced diameter portion 15 to press and contract the spring 18 radially inward. A block presser collar 19 and a recovery member 6 mounted on the block presser member 12 and pulling the block presser member 12 backward to release the outer bit 3 and the inner bit 4 from being fixed by the connecting block 10 and recover the inner bit 4. Therefore, the inner bit 4 can be easily fixed to the outer bit 3 and the drilling device 1 can be easily assembled.

  In addition, since the malfunction prevention spring 29 is provided on the inner bit 4 to urge and urge the block pressing member 12 forward, the block pressing member 12 moves rearward by striking or the like, and the inner bit 4 and the outer bit 3 are moved. Can be easily prevented with a simple structure.

  Since the block retainer collar 19 has an inclined surface 30 for guiding the spring 18 radially inward at the front end in the drilling direction, the spring 18 is placed when the block retainer collar 19 is put on the reduced diameter portion 15 of the outer bit 3. Can be easily pushed into the connecting block 10, and the assembly of the drilling device 1 can be further facilitated.

  The casing 2 is screwed to the rear end portion of the reduced diameter portion 15 so as to cover the outer peripheral surface thereof, and is fixed with a block presser collar 19 between the stepped portion 22 that is enlarged in front of the reduced diameter portion 15. Therefore, the block presser collar 19 can be easily fixed with a simple structure.

  The present invention is not limited to the above-described embodiment, and various design changes and the like can be made without departing from the gist of the present invention. For example, in the present embodiment, the hole is drilled perpendicularly to the ground, but it is needless to say that the present invention may be used for drilling horizontally on a slope, vertical surface, or the like where the earth and sand are exposed.

  It is also possible to replace the inner bit 4 with a down-the-hole hammer or the like.

It is a sectional side view of the drilling apparatus which shows suitable embodiment of this invention. It is AA arrow sectional drawing of FIG. It is a sectional side view of an outer bit. It is the sectional side view which decomposed | disassembled the inner bit into the front cutting block and the rear base. It is a BB line arrow directional view of FIG. It is a sectional side view of a block pressing member. It is assembly explanatory drawing which shows the procedure which assembles a block pressing member to an inner bit. (A) is a sectional side view of the state in which the block pressing member is assembled to the inner bit, and (b) is a rear view of (a). It is assembly explanatory drawing which shows the 1st procedure of attaching an inner bit to an outer bit. It is an assembly explanatory view showing a second procedure for assembling the inner bit to the outer bit. It is assembly explanatory drawing which shows the procedure of attaching a casing to an outer bit. It is a schematic explanatory drawing of the collection | recovery operation | work of an inner bit. It is explanatory drawing which shows the 1st collection | recovery procedure of an inner bit. It is explanatory drawing which shows the 2nd collection | recovery procedure of an inner bit. It is explanatory drawing which shows the 3rd collection | recovery procedure of an inner bit. It is a sectional side view of the conventional drilling apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drilling device 2 Casing 3 Outer bit 4 Inner bit 6 Collecting member 10 Connection block 12 Block pressing member 15 Reduced diameter part 16 Through hole 17 Through hole 18 Spring 19 Block pressing collar 22 Step part 29 Malfunction prevention spring 30 Inclined surface

Claims (4)

A hollow cylindrical casing, an outer bit connected to one end of the casing and formed into a hollow cylindrical shape, excavating earth and sand at the tip, and having a reduced diameter portion at the rear in the drilling direction, and the outer bit A bottomed cylindrical inner bit for excavating earth and sand on the inner peripheral side of the outer bit, a through hole formed through the reduced diameter portion and the inner bit in the radial direction, and a through hole A connecting block for inserting the inner bit to the outer bit, and a radially inward contact with the connecting block at the front position provided in the inner bit so as to be slidable within a predetermined range in the front-rear direction. And a block presser member that releases from the connection block when it is moved to the rear position and releases the movement restriction to the connection block radially outward. A spring that is extended and radially expands and contracts, a block presser collar that is provided over the outer periphery of the reduced diameter portion and that compresses the spring inward in the radial direction, and a block presser member that is mounted on the block presser member A drilling device comprising: a pulling member to release the outer bit and the inner bit fixed by the connecting block, and a collecting member for collecting the inner bit. 2. The hole drilling device according to claim 1, wherein a spring for preventing malfunction is provided on the inner bit to elastically bias the block pressing member forward. 3. The drilling device according to claim 1, wherein the block presser collar has an inclined surface for guiding the spring radially inward at a front end in the drilling direction. The casing is screwed onto the rear end portion of the reduced diameter portion so as to cover the outer peripheral surface thereof, and is fixed with the block presser collar sandwiched between the stepped portion that is enlarged in front of the reduced diameter portion. The drilling device according to any one of claims 1 to 3, wherein the drilling device is configured.

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