JP2006152602A - Excavator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excavator capable of surely transmitting rotation, without requiring to arrange an installation hole for incorporating a rotation transmitting part. <P>SOLUTION: A connecting hole 12 in the longitudinal direction is formed on the tip of a device 6 for receiving impact force and torque. A connecting shaft 16 arranged on the base end in the longitudinal direction of a bit device 15, is rotatably inserted into and connected to this connecting hole 12. In the device 6, a bit stopper 13 is arranged on an inner peripheral surface of the connecting hole 12, and the rotation of the device 6 is transmitted to the bit device 15 by engaging this bit stopper 13 with an engaging groove 17. A storage recessed part 61 is arranged on the inner peripheral surface of the device 6, and the bit stopper 13 is installed in this storage recessed part 61. The rotation can be stably transmitted over a long period without requiring to arrange a hole for installing a pin being a conventional rotation transmitting part on an outside surface of the device 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a drilling apparatus used for excavation in which buried pipes are buried in the ground for water wells, anchor work, prevention of landslides, etc., and in particular, a connecting hole is formed at the tip of the device, and a bit device of the bit apparatus is formed in the connecting hole. The present invention relates to a drilling device that connects a connecting shaft provided at a base end in a freely rotatable manner, and rotates the bit device with respect to the device to expand a drilling diameter of the bit device.

  Conventionally, in a boring for embedding a buried pipe made of a steel pipe or the like, excavation is carried out while impacting and rotating a bit device provided at the tip of the buried pipe, and the buried pipe is added along with the excavation to advance. In order to facilitate the insertion of the buried pipe into the ground, a bit device having a bore diameter larger than that of the buried pipe is used.

  For example, a connecting hole in the length direction is formed at the tip of the device that receives the impact force and rotational force of the air hammer, and a connecting shaft provided at the base end in the length direction of the bit device is rotatably inserted into this connecting hole. Connecting, rotating the device to one side in the circumferential direction by a predetermined angle with respect to the bit device to enlarge the drilling diameter of the bit device, and drilling while rotating the bit device by one-side rotation of the device In this excavator, an excavator is proposed in which a plurality of enlarged wings that are rotatable in the radial direction are pivotally supported on the device. In this excavator, when the device is advanced with respect to the bit device, the holding portion of the bit device comes into contact with the enlarged blade and the enlarged blade expands. Thereby, the drilling diameter of the bit device is expanded. In addition, a plurality of discharge grooves for discharging the excavated earth and sand to the upper part of the buried pipe are provided vertically on the outer periphery of the device, and a connection hole is formed on the distal end side of the device, and rotates toward the inner surface of the connection hole. A transmission pin is provided horizontally, and this rotation transmission pin is detachably fixed to a mounting hole formed in the discharge groove of the device, and is prevented from being detached by a lock pin. I try to communicate to the device. (For example, patent document 1).

  Further, in order to pivotally support the expansion wing on the device, in the excavation apparatus for excavating the tip of the bit device and the expansion wing from the tip of the buried pipe, a pivoting shaft protruding from both sides of the expansion wing is provided, A pair of left and right engaging grooves for pivoting both ends of the pivot shaft are formed on the opposing side wall surfaces of the mounting groove, and the engaging grooves are opened on the inner surface of the device. The front end side of the receiving shaft is formed in a spherical shape, and the cross-sectional shape of the engaging groove that engages with the pivoting shaft is formed in a substantially semicircular shape. In this excavator, the pivot shaft and the engaging groove are smoothly fitted, and the movement of the enlarged wing is also smooth (for example, Patent Document 2).

In these excavators, a bit casing pipe is welded to the tip of a buried pipe made of a steel pipe or the like, and this bit casing pipe has a thick portion at the tip through an inner peripheral step. . An air hammer is inserted into the buried pipe, and a cylindrical portion of the device base end is connected to the air hammer. A spline groove is integrally formed on the outer periphery of the cylindrical portion, and the vertical groove of the air hammer is The spline groove is fitted so that the rotation of the air hammer is transmitted to the device, and the air hammer has a built-in hammer piston that uses compressed air as a power source. Strike the tube to transmit impact force. In the outer periphery of the device, three discharge grooves for discharging earth and sand excavated along the axial direction of the device to the upper side of the buried pipe are vertically arranged at equal intervals, and in the inner peripheral step portion of the bit casing pipe. An outer peripheral step portion to be engaged is provided around. And the outer peripheral step part of a device contact | abuts to the inner peripheral step part of a bit casing pipe, and the impact from an air hammer is transmitted also to a bit casing pipe (for example, patent documents 1 and 2).
Japanese Patent No. 2710192 JP 2002-285778 A

  First, in the conventional bit device, rotation of the device is transmitted to the bit device by the rotation transmission pin, and the rotation transmission pin is inserted into the connection hole from the mounting hole formed in the discharge groove of the device. Although it is inserted into the ring and is prevented from being pulled out by a lock pin, etc., it will rotate while being hit by an air hammer during excavation, so the lock pin may be damaged and the rotation transmission pin may be displaced or pulled out, making it impossible to excavate. There is. In addition, the mounting hole is formed in the discharge groove on the outer surface of the device, and since the earth and sand excavated along the discharge groove are discharged, the mounting hole becomes resistance to discharging the earth and sand, and the mounting hole is worn by the sand and locked. There is a possibility that a phenomenon such as pin disconnection may occur. Further, the connecting shaft of the bit device has a groove formed in the portion engaging with the rotation transmission pin, and the connecting shaft is thinned at the portion where the groove portion is formed, so that the groove portion is easily damaged by metal fatigue. It has become.

  Secondly, in the excavating apparatus, a bit casing pipe is provided at the tip of a buried pipe made of a steel pipe or the like, the outer peripheral step portion of the device abuts on the inner peripheral step portion of the bit casing pipe, and the impact from the air hammer. Has a structure for transmitting to the bit casing pipe. The steel pipe used for the buried pipe is used by selecting the wall thickness according to the use conditions, but this type of steel pipe is a general-purpose product with a different wall thickness based on the outer diameter. With a diameter of 150 mm, there are carbon steel pipes for piping with an outer diameter of 165.2 mm and a wall thickness of 5.0 mm, and carbon pipes for pressure piping with a thickness of 7.1 mm (schedule 40). When different steel pipes are used, the inner diameter changes. On the other hand, since the outer diameter of the outer peripheral step portion is formed in accordance with the inner diameter of the steel pipe in the device, a device having a size adapted to the carbon steel pipe for pressure piping having a smaller inner diameter is used for the carbon for piping. If it is used for a steel pipe, the gap between the outer peripheral step and the inner circumference of the steel pipe becomes too large, and an appropriate clearance cannot be obtained. For this reason, a device has to be prepared in accordance with the inner diameter of the steel pipe to be used.

  Thirdly, in the excavator, the tip end side of the pivot shaft is formed in a spherical shape, and the cross-sectional shape of the engagement groove that engages with the pivot shaft is formed in a substantially semicircular shape. The pivot shaft and the engaging groove fit smoothly, and the movement of the enlarged wing becomes smooth as compared with the prior art. However, since the pivoting shaft is inserted into the expansion wing, and the expansion wing rotates relative to the pivoting shaft, friction occurs between the pivoting shaft and the expansion wing. There are problems such as rattling on the wings.

  Therefore, the present invention firstly does not need to incorporate a rotation transmission part and provide a mounting hole, and can transmit the rotation of the device to the bit device well, and secondly, it is used for a buried pipe having a different thickness. Thirdly, an object of the present invention is to provide a drilling device that can reduce wear of a stirring blade.

  According to the first aspect of the present invention, a connecting hole in the length direction is formed at the tip of a device that receives impact force and rotational force, and a connecting shaft provided at the base end in the length direction of the bit device can be freely rotated in the connecting hole. The device is provided with a rotation transmission portion on the inner peripheral surface of the connection hole, and an engagement groove with which the rotation transmission portion is engaged is formed on the outer periphery of the connection shaft in the length direction of the connection shaft. Forming the bit device so that the device can move forward and backward with respect to the device by moving the rotation transmission portion along the engagement groove, and locking the rotation transmission portion to the proximal end of the engagement groove In the excavating apparatus that increases the drilling diameter by providing a retaining part to be retracted and retracting the bit device with respect to the device, the rotation transmitting part is attached from the inside of the connecting hole.

  According to a second aspect of the present invention, the bit device and the device are inserted into an embedded pipe, an inner peripheral step is formed on a tip side of the embedded pipe, and an outer peripheral step that engages with the inner peripheral step is provided. It is provided in the device, and the device is such that the outer peripheral step portion is replaceable.

  According to a third aspect of the present invention, there is provided a device tip portion obtained by dividing the tip portion of the device, and a storage recess for storing the rotation transmitting portion is provided in the device tip portion.

  According to a fourth aspect of the present invention, the device includes the device distal end portion, a device ring portion having the outer peripheral stepped portion, and a proximal end device proximal end portion.

  According to a fifth aspect of the present invention, an enlarged wing that is rotatable in the radial direction is pivotally supported at the tip of the device by a pivotal support portion, and the bit device is moved backward with respect to the device to enlarge the enlarged wing. A mounting groove for accommodating the enlarged wing on the device side by the advancement of the bit device with respect to the device is provided in the device, and the pivotal support portion is formed in a hemispherical recess formed in the enlarged wing, and the mounting groove. The spherical portion is formed and a sphere disposed between the hemispherical concave portion and the spherical portion.

  According to the configuration of claim 1, by adopting a configuration in which the rotation transmitting portion is attached from the inside of the device, there is no need to provide a hole for attaching a pin as in the conventional case on the outer surface of the device, for example, the discharge groove. There is no risk of damage to the member that transmits the rotation to the hole portion of the outer surface or the bit device, and the rotation can be stably transmitted over a long period of time. Moreover, since it is not necessary to provide a hole in the discharge hole and it can be formed in a flat shape, it can be discharged smoothly from the discharge groove to the ground.

  Moreover, according to the structure of Claim 2, the impact from a device to a bit casing pipe can be favorably transmitted by replacing | exchanging only the part of an outer peripheral step part according to the internal diameter of a buried pipe.

  According to the third aspect of the present invention, it is possible to assemble after removing the device tip and storing the rotation transmitting portion in the storage recess in the detached device tip.

  Moreover, according to the structure of Claim 4, a device can be comprised combining three members of a device front-end | tip part, a device ring part, and a device base end part, or three or more members, and it rotates by removing a device front-end | tip part. The device ring part can be exchanged according to the inner diameter dimension of the buried pipe by assembling the transmission part.

  According to the fifth aspect of the present invention, the expanding blade is pivotally supported in the mounting groove by the sphere disposed between the hemispherical concave portion of the expanding blade and the spherical portion of the mounting groove, Since the structure is a combination of the above, a part of the pivot is not worn, and a stable pivot structure can be obtained for a long time.

  Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below do not limit the contents of the present invention described in the claims. In addition, all of the configurations described below are not necessarily essential requirements of the present invention. In each embodiment, an unprecedented excavator is obtained by adopting a new excavator different from the conventional one, and the excavator will be described.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 10 show an embodiment of the present invention. As shown in the figure, a bit casing pipe 2 is welded to the tip of an embedded pipe 1 made of a steel pipe or the like. A thick portion 4 is provided at the tip via the inner peripheral step portion 3. An air hammer 5 is inserted into the buried pipe 1, and a cylindrical portion 7 at the base end of the device 6 is connected to the air hammer 5. A spline groove 8 is integrally formed on the outer periphery of the cylindrical portion 7, The spline groove 8 is fitted into the vertical groove 9 of the air hammer 5 so that the rotation of the air hammer 5 is transmitted to the device 6. Further, the air hammer 5 powers compressed air or the like. A hammer piston (not shown) serving as a source is incorporated, and the hammer piston strikes the cylindrical portion 7 to transmit an impact force. On the outer periphery of the device 6, three discharge grooves 10 for discharging earth and sand excavated along the axial direction of the device 6 to the upper side of the buried pipe 1 are vertically arranged at equal intervals, and the bit casing pipe 2 An outer peripheral step portion 11 that engages with the inner peripheral step portion 3 is provided around the outer peripheral step portion 11, and a large diameter portion 11A that is larger in diameter than the distal end side is formed on the proximal end side of the outer peripheral step portion 11.

  A connecting hole 12 in the length direction is formed on the distal end side of the device 6, and a bit stopper 13 serving as a rotation transmitting portion is provided on the inner periphery of the connecting hole 12 on the distal end side. A connecting shaft 16 at the base end of the bit device 15 is inserted into the connecting hole 12 so as to be rotatable and vertically slidable. The outer periphery of the connecting shaft 16 is engaged with the bit stopper 13 so that the bit device 15 has a predetermined angle. An engagement groove 17 is formed to be rotatable. As shown in FIG. 3 and the like, the engagement groove 17 is formed so that the bit stopper 13 can rotate approximately 90 degrees along the outer periphery of the connecting shaft 16. One side engagement surface 18 that is a transmission engagement portion that transmits the rotation of the device 6 in one side direction R to the bit device 15 via the 13 and the other side engagement that transmits the rotation in the other side direction to the bit device 15 The engaging groove 17 is formed to be slightly larger than the width of the bit stopper 13 (the width in the device length direction), and the other engaging groove 17 on the tip side is formed. Above the end-side engagement surface 19, as shown in FIG. 8 and the like, the bit device 15 is engaged with the bit stopper 13 in the longitudinal direction in a longitudinal direction and continuously with the other-side engagement surface 19. A slide groove portion 20 having a flat surface that can be retracted is formed.

  As shown in FIG. 1, three mounting grooves 21 are formed at the front end of the device 6 at equal circumferential intervals so as to open at the front end surface of the device 6. Is pivotally supported. On the base end side of the expansion wing 23, a pair of hemispherical recesses 24, 24 are formed on both side surfaces thereof, and the hemispherical recess 24 is formed in a smooth hemispherical shape and is made of steel serving as a connecting portion. Sphere 25 is engaged. Corresponding to these hemispherical recesses 24, 24, a pair of left and right engagement grooves 26, 26 into which the spherical body 25 is engaged are formed on opposite side wall surfaces of the mounting groove 21, and this engagement groove 26 The base end of the device 6 is open to the inner surface of the device 6, and the tip thereof is formed with a smooth hemispherical spherical surface portion 26A.

  Then, as shown in FIGS. 5 to 7 and the like, the sphere 25 is inserted along the engaging groove 24 from the inside of the device 6 with the sphere 25 engaged in the hemispherical recess 24. Thus, the sphere 25 is disposed between the hemispherical recess 24 and the hemispherical portion 26A, and the expanding wings 23 are rotatably provided in the mounting grooves 21 by the spheres 25, 25 on both sides. It is attached to a center axis of 15 so as to be rotatable in a radial direction. A flat shoulder surface 23A that abuts against the inclined inner end surface 21A of the mounting groove 21 in the expanded state of the expansion blade 23 is formed at the base end of the expansion blade 23, and is continuous with the shoulder surface 23A. Thus, a curved surface 27 with the hemispherical recess 24 as the center is formed. A pivotal support 28 is constituted by a hemispherical recess 24 formed in the enlarged wing 23, a spherical portion 26A formed in the mounting groove 21, and a sphere 25 arranged between the hemispherical recess 24 and the spherical portion 26A. is doing.

  Further, as shown in FIG. 2 and the like, the enlarged wings 23 can be inserted in the embedded pipe 1 and the bit casing pipe 2 in a contracted state on the distal end side of the connecting shaft 16 of the bit device 15. A tapered surface 31 and a circumferential surface 32 continuous with the tapered surface 31 are formed at the tip of the bit device 15, and the enlarged wing 23 is moved by contacting the tapered surface 31 with the inner side surface 23B of the enlarged wing 23. Hold in an expanded state. Further, a plurality of tips 33 made of cemented carbide are provided on the tip surfaces of the expanding blade 23 and the bit device 15, and the tip surface of the expanding blade 23 has a substantially square shape, and the outer center and inner side thereof The tip 33 is provided on the left and right, and a hard-facing portion 34 that is harder than the enlarged blade 23 is provided on the side surface on the tip side of the enlarged blade 23 by arc welding or the like.

  In the device 6, a passage 41 communicating with the air hammer 5 is formed, and a compressed air passage 42 communicating with the passage 41 is formed in the bit device 15, and three branch passages 42A, 42A and 42A are opened in the front end surface of the body peripheral surface 32 of the bit device 15.

  As shown in FIG. 1, the device 6 includes a device tip portion 51 on the tip side having the mounting groove 21, a device ring portion 52 having the outer peripheral step portion 11 and the large diameter portion 11 </ b> A, and the cylindrical portion 7. And a device base end portion 53 having three parts. The device tip portion 51 and the device ring portion 52 are divided on the tip side of the large diameter portion 11A, and a plurality of radial engaging grooves 54 are provided in the device tip portion 51 on the ring-shaped dividing surface. At the same time, a protrusion 55 that engages with the engagement groove 54 is provided in the device ring portion 52. At the distal end of the device base end portion 53, an insertion connecting portion 56 to be inserted into the base end side of the device ring portion 52 and the device distal end portion 51 is formed, and a male screw portion 56A is provided on the outer periphery of the distal end of the insertion connecting portion 56. A female screw hole 51A into which the male screw portion 56A is screwed is formed on the proximal end side of the device distal end portion 51. The female screw hole 51A is formed larger in diameter than the connecting hole 12, and The base end portion 53 is formed with a contact portion 57 that contacts the base end side surface of the device ring portion 52 in a state where the device ring portion 52 is sandwiched therebetween and the male screw portion 56A is screwed into the female screw hole 51A. Has been. Further, a distal end side of the device distal end 51 is formed with a distal end portion 12A of the coupling hole 12, which is the distal end side of the coupling hole 12, and the distal end of the insertion coupling portion 56 is the proximal end side of the coupling hole 12. A connecting hole base end portion 12B is formed. The male screw portion 56A and the female screw hole 51A are screws that are tightened by the same rotation as the rotation direction when the bid apparatus 1 is excavated.

  Then, with the protrusion 55 inserted into the engagement groove 54, the male screw portion 56A of the device base end portion 53 is inserted into the device ring portion 52 and the device front end portion 51 from the base end side, and the male screw When the portion 56A is screwed into the female screw hole 51A, the contact portion 57 comes into pressure contact with the proximal end side surface of the device ring portion 52, so that the device ring portion 52 is sandwiched between the device distal end portion 51 and the device proximal end portion 53. In this state, the device 6 is assembled. In this assembled state, the connecting hole distal end portion 12A and the connecting hole base end portion 12B communicate with each other to form the connecting hole 12.

  As shown in FIG. 1, the bit stopper 13 is substantially bowl-shaped and includes a transmission surface 13 </ b> A that is a flat inner surface facing the connection hole 12. On the other hand, the device base end portion 51 is formed with a storage recess 61 on the base end side of the connecting hole tip end portion 12A. The storage recess 61 is open on the base end side and has a retaining surface 62 on the tip end side. . The outer side of the bit stopper 13 is stored in the storage recess 61, and the transmission surface 13A side projects into the connecting hole 12 in the stored state. Further, in the state where the outer surface side of the bit stopper 13 is housed in the housing recess 61 and the device 6 is assembled, the bit stopper 13 is sandwiched between the distal end surface of the insertion coupling portion 56 and the retaining surface 62 and is connected to the coupling groove. Positioned and fixed in the length direction.

  On the base end face 13B of the bit stopper 13, a female screw hole 63 as a tool engaging portion is formed. As shown in FIGS. 1 and 9, reference numeral 64 denotes an insertion tool for assembling the bit stopper 13 in the device 6, which has a long bolt shape, and the tip is screwed into the female screw hole 63. Match.

  The slide groove portion 20 of the bit device 15 is continuously formed to the base end of the connecting shaft 16, and a ring-shaped groove portion 65 is provided around the base end side of the connecting shaft 16, and a stopper ring is provided on the ring-shaped groove portion 65. The split stopper rings 66 and 66 that are divided into two are externally fitted, and the split stopper rings 66 and 66 are formed with engaging grooves 68 for externally fitting the O-ring 67 as an assembly member. In the state where the rings 66 and 66 are externally fitted, the outer diameters of the divided stopper rings 66 and 66 are the same as the outer diameter of the connecting shaft 16. The split stopper rings 66 and 66 are retaining portions provided at the base end of the connecting shaft 16 and are locked to the base end surface 13B of the bit stopper 13.

  Next, a method for assembling the device 6 and the bit device 15 will be described. First, in order to set the expansion wing 23 on the device tip 51, the sphere 25 is inserted into the engagement groove 26 from the inside of the device 6 with the sphere 25 engaged in the hemispherical recess 24 of the expansion wing 23. Insert along. Then, before inserting the connecting shaft 16 into the connecting hole distal end portion 12A, as shown in FIG. 9, the expanding blade 23 is temporarily fixed at the expanding position. For this temporary fixing, an adhesive tape 101 or the like can be used. Then, the connecting shaft 16 of the bit device 15 is inserted into the connecting hole tip 51A of the device tip 51 and rotated to align the slide groove 20 of the connecting shaft 16 with the storage recess 61 for the bit stopper. Here, a tool 64 is screwed into the bit stopper 13, and the tool 64 is used to insert the bit stopper 13 between the slide groove portion 20 and the storage recess 61, and after storing in the storage recess 61, the screw is inserted. Unscrew the tool 64 in the direction to release the wear, and remove only the tool 64.

  While the tip end side of the connecting hole 12 is outside the device 6, the bit stopper 13 is inserted into the connecting hole 12 of the device 6 and assembled from the inside of the connecting hole 12 in this way.

  Next, the split stopper rings 66 and 66 are assembled to the ring-shaped groove portion 65 of the connecting shaft 16 using an O-ring 67. Accordingly, the split stopper rings 66 and 66 are positioned on the proximal end side of the slide groove portion 20. Then, the device ring portion 52 is aligned with the device tip portion 51. In this case, the device tip portion 51 and the device are connected by engagement of a plurality (three in this example) of engagement grooves 54 and the protrusions 55 provided radially. The axial center of the ring portion 52 is positioned, the insertion coupling portion 56 of the device base end portion 53 is inserted from the device ring portion 52 side, and the male screw portion 56A of the insertion coupling portion 56 is screwed into the female screw hole 51A. , Device 6 is assembled. Moreover, it can also disassemble | disassemble by the procedure reverse to this assembly. Then, when the device 6 side is lifted with the cylinder portion 7 facing up, the bit device 15 descends (advances) with respect to the device 6, and the split stopper ring 66 hits the bit stopper 13 and stops at the position. The inner surface 23B of the expansion wing 23 is disengaged from the body peripheral surface 32 and is in a state along the connecting shaft 16, and the expansion wing 23 is in a state of being contained in the outer periphery of the device tip 51, and can move in the buried pipe 1. Become.

  Next, the method of using the excavator will be described. As shown in FIG. 2, the bit device 15 is suspended in the device 6 and inserted into the buried pipe 1. Then, after the bit device 15 is grounded, the device 6 is pushed down while rotating in one side direction R, whereby the bit device 15 and the expanding wing 23 are pushed out from the tip of the bit casing pipe 2, and against the grounded bit device 15. When the device 6 advances, the bit stopper 13 advances to the front end of the slide groove portion 20. By this advancement, the connecting shaft 16 retreats in the connecting hole 13, and as shown in FIG. 4, the tapered surface 31 of the bit device 15 contacts the inner side surface 23B of the expanding blade 23, and the expanding blade 23 is held in the expanded state. In addition, the shoulder surface 23A of the expanding blade 23 is positioned in contact with the inner end surface 21A, and the drilling diameter P of the bit device 15 increases. At the same time, the rotation of the device 6 causes the bit stopper 13 to rotate in the one side direction R of the engagement groove 17 to engage the one side engagement surface 18, and the rotation in the one side direction R of the device 6 is transmitted to the bit device 15. The Further, in this state, the outer peripheral step portion 11 of the device 6 contacts the inner peripheral step portion 3 of the bit casing pipe 2, and the impact from the air hammer 5 is transmitted to the bit casing pipe 2. In this manner, for example, the bit device 15 is struck 1100 times per minute and rotated 20 times per minute while the expansion blade 23 is expanded, and the branch passages 42A, 42A, Excavation is performed by jetting compressed air from 42A. When excavation at a predetermined depth is completed, the device 6 is rotated in the other direction. By this rotation, the bit stopper 13 moves to the slide groove portion 20 side, and when the device 6 is pulled upward, the bit stopper 13 moves along the slide groove portion 20, and the expansion blade 23 is retracted and stored in the bit casing pipe 2. Thus, the bit device 15 can move in the buried pipe 1 and can be lifted to the ground.

  When excavation is performed using such a device for expanding the hole, the excavated earth and sand or clay is discharged upward along the discharge groove 10 of the device 6. In this apparatus, the bit stopper 13 is disposed inside the device 6. By adopting the mounting configuration, it is not necessary to provide a hole for mounting a pin as in the conventional case on the outer surface of the device, for example, the discharge groove 10, and the hole portion on the device outer surface and the member that transmits rotation to the bit device are damaged. There is nothing to do. Moreover, since it is not necessary to provide a hole in the discharge groove 10 and it can be formed in a flat shape, the discharge groove 10 can be smoothly discharged to the ground.

  Further, as described above, the outer peripheral step portion 11 of the device 6 comes into contact with the inner peripheral step portion 3 of the bit casing pipe 2, and the impact from the air hammer 5 is also transmitted to the bit casing pipe 2 so that the buried pipe 1 is grounded. Inserted inside. In such excavation, if the thickness of the buried pipe 1 is changed depending on conditions such as the ground and the excavation depth, the inner diameter of the buried pipe 1 changes. At this time, the diameter of the large diameter portion 11A of the device ring part 52 is changed. By making the size corresponding to each inner diameter dimension and exchanging only the device ring portion 52, the impact from the device 6 to the bit casing pipe 2 can be transmitted satisfactorily.

  Further, during excavation, the agitating blade 23 excavates the earth and sand while receiving the impact of the air hammer 5, and the force concentrates on the pivotally attached portion where the agitating blade 23 is attached to the device 6, and wear easily occurs. Since the pivoting portion is formed in a hemispherical shape and the sphere 25 is provided between the hemispherical concave portion 24 and the spherical portion 26A, the occurrence of wear is suppressed, and a stable mounting structure can be obtained over a long period of time. can get.

  Thus, in the present embodiment, corresponding to claim 1, the lengthwise connecting hole 12 is formed at the tip of the device 6 that receives impact force and rotational force, and the length of the bit device 15 is formed in the connecting hole 12. A connecting shaft 16 provided at the base end in the vertical direction is rotatably inserted and connected, and the device 6 is provided with a bit stopper 13 as a rotation transmitting portion on the inner peripheral surface of the connecting hole 12, and this bit stopper 13 is engaged. The engaging groove 17 is formed on the outer periphery of the connecting shaft 16 in the length direction of the connecting shaft 16, and the bit stopper 13 moves along the engaging groove 17 so that the bit device 15 moves forward and backward relative to the device 6. A split stopper ring 66, 66 is provided at the base end of the engagement groove 17 as a retaining portion for locking to the bit stopper 13, and the drilling diameter P is increased by retracting the bit device 15 relative to the device 6. The bit stopper 13 is attached from the inside of the connecting hole 12 Therefore, it is not necessary to provide a hole for attaching a pin as a conventional rotation transmission portion in the outer surface of the device 6, for example, the discharge groove 10, and the hole portion on the outer surface of the device 6 and the bit device 15 can be rotated. The transmitting member (bit stopper 13) is not damaged, and the rotation can be stably transmitted over a long period of time. Moreover, since it is not necessary to provide a hole in the discharge groove 10 and the discharge groove 10 can be formed in a flat shape, the soil can be discharged smoothly from the discharge groove 10 to the ground.

  In this way, in this embodiment, corresponding to claim 2, the bit device 15 and the device 6 are inserted into the buried pipe 1, and the inner peripheral step portion 3 is formed on the tip side of the buried pipe 1, An outer peripheral step portion 11 that engages with the inner peripheral step portion 3 is provided in the device 6, and since the outer peripheral step portion 11 is replaceable, the device 6 has a portion of the outer peripheral step portion 11 that matches the inner diameter of the buried pipe 1. By exchanging only, the impact from the device 6 to the bit casing pipe 2 can be transmitted well.

  In this way, in this embodiment, corresponding to claim 3, the device tip 51 is formed by dividing the tip of the device 6, and the bit stopper 13 serving as the rotation transmitting portion is accommodated in the device tip 51. Since the storage recess 61 is provided, the device tip 51 can be detached from the device 6 and the bit stopper 13 can be stored in the storage recess 61 in the detached device tip 51 and then assembled.

  In this way, in this embodiment, corresponding to claim 4, the device 6 includes a device distal end portion 51, a device ring portion 52 having an outer peripheral step portion 11, and a device proximal end portion 53 on the proximal end side. Therefore, the device 6 can be configured by combining three members or three or more members of the device distal end portion 51, the device ring portion 52, and the device proximal end portion 53, and the device stopper 51 is removed to remove the bit stopper 13. And the device ring portion 52 can be exchanged in accordance with the inner diameter of the buried pipe 1.

  Thus, in this embodiment, corresponding to claim 5, the expanding wing 23 that can be rotated in the radial direction is pivotally supported by the pivotal support portion 28 at the tip of the device 6, and the bit device 15 is mounted on the device 6. On the other hand, the expansion wing 23 is expanded by retreating, and a mounting groove 21 for accommodating the expansion wing 23 on the device 6 side is provided in the device 6 by advancement of the bit device 15 with respect to the device 6. Since the hemispherical concave portion 24 formed, the spherical portion 26A formed in the mounting groove 21, and the sphere 25 arranged between the hemispherical concave portion 24 and the spherical portion 26A, the expanding blade 23 is provided in the mounting groove 21. Since it is pivotally supported and has a structure in which the spherical surface and the sphere 25 are combined, the pivotal support portion 28 does not partially wear, and a stable pivotal support structure can be obtained over a long period of time.

  Further, as an effect of the embodiment, since the device front end portion 51 and the device base end portion 53 are screwed together and the device ring portion 52 is sandwiched therebetween, assembly work is easy, and further, these male screw portions. Since the 56A and the female screw hole 51A are made to be screws that are tightened in the same rotation direction as that during the excavation of the bid apparatus 1, they do not loosen during excavation. Further, since the transmission surface 13A on the inner surface is engaged with the engagement groove 17 in a surface contact state, the bit stopper 13 can reliably transmit the rotation. In addition, the device tip portion 51 and the device ring portion 52 are surely integrated by engaging the engaging groove 54 and the protrusion 55 with each other. Further, a female screw hole 63 as a tool engaging portion is formed in the base end side surface of the bit stopper 13, and the bit stopper 13 can be easily assembled to the storage recess 61 in the device 6 using the insertion tool 64. it can. Further, by using the split stopper rings 66 and 66 as the retaining portions, the connecting shaft 16 can be assembled and connected from the tip of the device 6.

  FIGS. 11 to 15 show a second embodiment of the present invention. The same reference numerals are given to the same parts as those of the first embodiment, and detailed description thereof is omitted. Wide portions 76, 76 are provided on the left and right sides on the distal end side, and inclined surfaces 77, 77 are provided on the left and right proximal ends of the wide portions 76, 76, respectively. On the distal end side of the mounting groove 21, a wide groove portion 78 is formed which is wider than the proximal end side and can be accommodated in the proximal end side of the wide portion 76. In the wide groove portion 78, the expanded blade 23 is in an enlarged state. A receiving surface 79 against which the inclined surface 77 abuts is provided.

  In addition, this invention is not limited to the said Example, A various deformation | transformation implementation is possible. For example, the size, shape, and number of enlarged blades can be selected as appropriate. The apparatus of the present invention can also be used for lateral excavation, and various types of air hammers can be used, and various means for rotating the air hammer can be used. it can.

It is a disassembled perspective view of the device and bit apparatus which show Example 1 of this invention. It is sectional drawing same as the above. It is sectional drawing of the principal part same as the above. It is sectional drawing of the state which expanded the expansion blade same as the above. It is a partially cutaway top view of the principal part which shows the attachment state of an expansion blade same as the above. FIG. 3 is a cross-sectional view around the enlarged wing. FIG. 4 is a cross-sectional view around the enlarged wing, showing a state where the enlarged wing is enlarged. It is sectional drawing explaining the assembly process of a device and a bit apparatus same as the above. It is sectional drawing explaining the attachment process of the rotation transmission part to a device same as the above. It is a front view of a division | segmentation stopper ring same as the above. It is a disassembled perspective view of the bit front-end | tip part and expansion blade which shows Example 2 of this invention. It is a top view of an enlarged wing | blade same as the above. It is a front view of an expansion wing same as the above. FIG. 3 is a cross-sectional view around the enlarged wing. FIG. 4 is a cross-sectional view around the enlarged wing, showing a state where the enlarged wing is enlarged.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Embedded pipe 2 Bit casing pipe 3 Inner peripheral step part 5 Air hammer 6 Device
10 Discharge groove
11 Outer peripheral step
11A diameter large part
12 Connecting hole
13 Bit stopper (rotation transmission part)
15-bit device
16 Connecting shaft
17 Engaging groove
18 One side engagement surface (transmission engagement part)
19 Other side engagement surface (other side engagement surface)
20 Slide groove
21 Mounting groove
23 Expanded wing
24 Hemispherical recess
25 sphere
26 Engaging groove
28 Pivot
51 Device tip
52 Device ring section
53 Device base
61 Storage recess P Drilling diameter

Claims (5)

A connecting hole in the length direction is formed at the tip of a device that receives impact force and rotational force, and a connecting shaft provided at the base end in the length direction of the bit device is rotatably inserted into and connected to the device. A rotation transmission portion is provided on an inner peripheral surface of the connection hole, and an engagement groove that engages with the rotation transmission portion is formed in the length direction of the connection shaft on the outer periphery of the connection shaft, and the rotation transmission portion Is moved along the engagement groove so that the bit device can be moved forward and backward with respect to the device, and a retaining portion for locking the rotation transmitting portion is provided at the base end of the engagement groove, An excavator that enlarges a drilling diameter by retracting the bit device with respect to the device, wherein the rotation transmitting portion is attached from the inside of the connecting hole. The bit device and the device are inserted into an embedded pipe, an inner peripheral step is formed on the distal end side of the embedded pipe, and an outer peripheral step that engages with the inner peripheral step is provided in the device. The excavator according to claim 1, wherein the outer peripheral step is replaceable. The excavation apparatus according to claim 1 or 2, wherein a device tip portion obtained by dividing the tip portion of the device is formed, and a storage recess for storing the rotation transmitting portion is provided in the device tip portion. 4. The excavator according to claim 3, wherein the device includes the device distal end portion, a device ring portion having the outer peripheral stepped portion, and a proximal device end portion. A magnifying wing that is rotatable in a radial direction is pivotally supported at the tip of the device by a pivot, and the magnifying wing is enlarged by retracting the bit device with respect to the device. A mounting groove for accommodating the enlarged wing on the device side by advancement is provided in the device, and the pivot portion includes a hemispherical concave portion formed in the enlarged wing, a spherical portion formed in the mounting groove, and the hemisphere. The excavator according to any one of claims 1 to 4, wherein the excavator is formed of a spherical body disposed between the concave portion and the spherical portion.

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