JP4150830B2 - Steel pipe pile cutting machine and cutting method - Google Patents

Description

  The present invention relates to a cutting machine and a cutting method for cutting a steel pipe pile penetrating into the ground from the inside.

  As is well known, as a method for preventing uneven settlement when constructing a building or the like on soft ground or embankment, a method of penetrating a plurality of steel pipe piles to the support layer of the ground is representative. In this method, long steel pipe piles are used in consideration of the unevenness of the support layer. Therefore, the steel pipe pile after intrusion protrudes upward from the ground, and the protrusion length differs depending on the intrusion location. It is common to cut and remove unnecessary portions of such steel pipe piles at a cutting level set underground. In this cutting operation, the ground around the steel pipe pile is excavated to a predetermined depth to form a working hole, and the steel pipe pile is often gas-cut from the outside at an underground cutting level. However, in this case, it takes time and effort to form the working hole, and it is necessary for the worker on the ground to perform the cutting work with the head lowered and reaching to the underground cutting level. There was a problem of being bad. Moreover, since the cut surface of the steel pipe pile by gas cutting is poor in smoothness, there is also a problem that grinding work of the cut surface by a grinder or the like is necessary.

Then, in order to solve such a problem, the cutting machine which cuts the steel pipe pile penetrated into the ground from the inside is proposed (for example, refer to patent documents 1).
JP2003-136328A (FIGS. 4, 9, etc.)

However, the conventional cutting machine as described above has the following problems (1) and (2).
(1) Since the cutting machine is placed on the head of the steel pipe pile, the length of the steel pipe pile projecting upward from the ground by performing gas cutting of the steel pipe pile and grinding of the cut surface in advance. It is necessary to adjust it accurately so that it becomes the set length.
(2) The cutter arm is provided with a cam groove and a cutting blade, and the cutting blade is moved outward when the cam portion of the feed cam is inserted into the cam groove and the cutter arm rotates in a horizontal plane. Therefore, the moving mechanism of the cutting blade is complicated and expensive.

  The present invention has been made in view of the above circumstances and problems, and it is not necessary to accurately adjust the protruding length of the steel pipe pile upward from the ground, and it is possible to reduce the cost. An object is to provide a pile cutting machine and a cutting method.

  A steel pipe pile cutting machine according to claim 1 for achieving the above object is a cutting machine for cutting a steel pipe pile penetrating into the ground from the inside, wherein the steel pipe pile cutting machine is formed in a substantially cylindrical shape and has a head portion of the steel pipe pile. A fixed cylinder that is fixed to the outer peripheral surface of the steel pipe pile concentrically with the steel pipe pile so that a predetermined length is inserted from below into the inside, and a substantially cylindrical shape formed around the axis of the fixed cylinder. A rotating cylinder supported so as to protrude downward by a predetermined length from the lower edge of the fixed cylinder, and to be rotatable about the axis of the fixed cylinder in the rotating cylinder. A feed shaft that is supported so as to protrude downward from the lower edge portion of the fixed cylindrical body, and a truncated cone shape that is screwed concentrically with the feed shaft at the distal end portion of the feed shaft. A feed cone provided with a plurality of guide grooves extending in the generatrix direction on the surface, and a tip of the rotating cylinder A cutting blade receiver that is provided so as to be movable in the radial direction and provided with an inclined portion that fits in the guide groove of the feed cone on the inner end side, and provided on the outer end side of the cutting blade receiver so as to be rotatable in a horizontal plane. And a rotary driving means for driving the rotary cylinder and the feed shaft in the same direction so that the rotational speed of the feed shaft is larger than the rotational speed of the rotary cylinder. Is.

  In the steel pipe pile cutting machine according to claim 2, the guide groove of the feed cone and the inclined portion of the cutting blade receiver are connected by a dovetail joint.

  The steel pipe pile cutting machine according to claim 3 is provided with a biasing means for biasing the feed cone downward.

  The steel pipe pile cutting machine according to claim 4 is provided with a ring-shaped guide collar interposed between the inner peripheral surface of the fixed cylinder and the outer peripheral surface of the steel pipe pile.

  Moreover, the cutting method of the steel pipe pile of Claim 5 is a method of cut | disconnecting the steel pipe pile penetrated in the ground from the inside with the cutting machine of the steel pipe pile of any one of Claim 1 to 4, Comprising: The said rotation cylinder The body is inserted into the steel pipe pile from above, the head of the steel pipe pile is inserted into the fixed cylinder from the lower side for a predetermined length, and the fixed cylinder is fixed to the outer peripheral surface of the steel pipe pile. Then, the rotary cylinder and the feed shaft are rotationally driven by the rotary drive means in the same direction and the rotational speed of the feed shaft is larger than the rotational speed of the rotary cylinder.

  According to a sixth aspect of the present invention, the cutting machine is mounted on a positioning ring that is externally fitted to the steel pipe pile and fixed to the outer peripheral surface of the steel pipe pile at a predetermined height on the ground.

  According to the invention of claim 1, since the moving mechanism of the cutting blade that moves by the feed cone and the cutting blade receiver is relatively simple, the cost can be reduced. Moreover, since the fixed cylinder can be fixed at an appropriate height on the ground, it is not necessary to accurately adjust the protruding length of the steel pipe pile upward from the ground.

  According to the invention of claim 2, since the guide groove of the feed cone and the inclined portion of the cutting blade receiver are connected by a dovetail joint, the cutting blade can be accommodated in the steel pipe pile by a simple operation.

  According to the invention of claim 3, since the biasing means for biasing the feed cone downward is provided, even when the screw engagement between the female screw of the feed cone and the male screw of the feed shaft is released, the feed cone If the operation of returning the screw is performed downward, the screwing can be immediately returned.

  According to the invention of claim 4, since the fixed cylinder can be fixed to the outer peripheral surface of the steel pipe pile via the guide collar, the guide collar can be exchanged according to the outer diameter of the steel pipe pile. Therefore, if guide collars with various inner diameters are prepared, it is possible to cope with steel pipe piles with various outer diameters.

  According to the invention of claim 5, the steel pipe pile can be cut from the inside using a relatively inexpensive cutting machine, and it is not necessary to accurately adjust the protruding length of the steel pipe pile from the ground. The construction cost of piles can be reduced.

  According to the sixth aspect of the present invention, since it is not necessary to perform positioning while supporting a cutting machine that is larger and heavier than the positioning ring, the cutting machine can be positioned easily.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The cutting machine 1 which concerns on this embodiment cuts the steel pipe pile 3 penetrated in the ground 2, as shown in FIGS. 1-5, Comprising: As a main structural member, the fixed cylinder 4, A rotary cylinder 5, a feed shaft 6, a feed cone 7, a cutting blade receiver 8, a cutting blade 9, and a rotation driving means 10 are provided.

  The steel pipe pile 3 is formed in a circular tube shape as shown in FIG. On the outer peripheral surface 3c of the tip portion 3b of the steel pipe pile 3, a spiral blade 31 is projected. The opening 32 of the tip 3b of the steel pipe pile 3 is closed with a disc-shaped lid 33.

  The steel pipe pile 3 configured in this manner is rotated and penetrated into the ground 2 by a rotary penetration machine or the like (not shown) so that the steel pipe pile 3 protrudes upward from the ground 2a by a predetermined length and the tip 3b reaches the support layer 2b. As shown in FIG. 5, unnecessary portions of the steel pipe pile 3 after penetration are cut and removed by a gas cutting machine or the like at an appropriate height above the ground. In addition, the unnecessary part of the steel pipe pile 3 may be cut by rough cutting performed at an appropriate height on the ground, and the grinding work of the cut surface 34 is also unnecessary. Moreover, the structure and penetration method of the steel pipe pile 3 are not specifically limited, Conventionally well-known various techniques can be utilized.

  The fixed cylinder 4 is formed in a substantially cylindrical shape as shown in FIG. A support plate 41 is provided in the fixed cylinder 4 in a direction perpendicular to the axial direction. The opening 42 of the upper edge 4a of the fixed cylinder 4 is detachably closed with a disc-shaped lid 43. A ring-shaped guide collar 45 is fixed to the opening 44 of the lower edge 4b of the fixed cylinder 4 so as to be detachable in a direction perpendicular to the axial direction. The guide collar 45 is provided with a fixing bolt 47 (1 in FIG. 1) that is inserted from the outside to the inside, for example, through three insertion holes 46 formed in the fixed cylinder 4 at predetermined intervals in the circumferential direction. Only one insertion hole 46 and one fixing bolt 47 are shown in the drawing) and are screwed so that the distal end abuts against the outer peripheral surface 3 c of the steel pipe pile 3. The numbers of the insertion holes 46 and the fixing bolts 47 are not particularly limited, and one or more insertion holes 46 and fixing bolts 47 can be provided.

  The fixed cylinder 4 configured as described above is configured so that the head 3 a of the steel pipe pile 3 is in a state where the guide collar 45 is interposed between the inner peripheral surface 4 d of the fixed cylinder 4 and the outer peripheral surface 3 c of the steel pipe pile 3. The steel pipe pile 3 is concentrically fixed to the outer peripheral surface 3c of the steel pipe pile 3 so as to be inserted into the inside from the lower side by a predetermined length. Thus, if the fixed cylinder 4 can be fixed to the outer peripheral surface 3 c of the steel pipe pile 3 via the guide collar 45, the guide collar 45 can be exchanged according to the outer diameter of the steel pipe pile 3. Therefore, if the guide collars 45 having various inner diameters are prepared, there is an advantage that the steel pipe piles 3 having various outer diameters can be handled. When the guide collar 45 is not used, the fixed cylinder 4 is configured so as to be externally fitted to the steel pipe pile 3, and at least one fixing bolt 47 is arranged in the radial direction and the distal end portion is on the outer peripheral surface 3 c of the steel pipe pile 3. What is necessary is just to screw to the fixed cylinder 4 so that it may contact | abut. In addition, when the steel pipe pile 3 has a short projecting length upward from the ground surface 2a and the head level of the steel pipe pile 3 is within the vertical adjustment allowance of the fixed cylinder 4, the steel pipe It is not necessary to cut the head 3a of the pile 3 in advance.

  The rotating cylinder 5 is formed in a substantially cylindrical shape, and is rotatable on a support plate 41 in the fixed cylinder 4 around the axis of the fixed cylinder 4 and downward from the lower edge portion 4b of the fixed cylinder 4 by a predetermined length. It is supported to protrude. The rotating cylinder 5 includes a driving cylinder 51, a connecting cylinder 52, a roller holder 53, a cutting blade holder 54, and a ring body 55 as main structural members. As shown in FIG. 6, the drive cylinder 51 is formed in a substantially cylindrical shape, and is rotatable on the support plate 41 in the fixed cylinder 4 so as to be rotatable around the axis of the fixed cylinder 4 and from the support plate 41. It is supported so as to protrude downward by a predetermined length. A drive gear 57 is bolted onto a flange portion 56 projecting from the head of the drive cylinder 51. As shown in FIG. 1, the connecting cylinder 52 is formed in a cylindrical shape. As shown in FIG. 6, the head of the connecting cylinder 52 is externally fitted to the tip of the drive cylinder 51 and bolted. As shown in FIG. 7, the roller holder 53 is formed in a substantially disc shape. On the upper surface side of the roller holder 53, a columnar protruding portion 58 protruding upward is provided. The distal end portion of the connecting cylinder 52 is externally fitted to the protruding portion 58 of the roller holder 53 and is bolted. The cutting blade holder 54 is formed in a substantially cylindrical shape and is disposed below the roller holder 53. The ring body 55 is formed in a ring shape and disposed below the cutting blade holder 54, and is bolted to the roller holder 53 via the cutting blade holder 54. As shown in FIGS. 1 and 8, the rotating cylinder 5 configured as described above is inserted into the steel pipe pile 3 from above.

  As shown in FIG. 1, the feed shaft 6 is rotatable about the axis of the fixed cylinder 4 and protrudes downward from the lower edge 4 b of the fixed cylinder 4 by a predetermined length in the rotary cylinder 5. It is supported. As shown in FIGS. 6 and 7, the feed shaft 6 is also supported so as to protrude upward by a predetermined length from the lid body 43, and to the lid body 43, the drive gear 57, and the roller holder 53. And is supported rotatably. As shown in FIGS. 1 and 6, the feed shaft 6 includes, as main structural members, a drive shaft 61 on the head 6a side, an extension shaft 62 on the tip 6b side, and the drive shaft 61 and the extension shaft 62. And a coupling 63 for connecting the two. As shown in FIG. 6, a feed gear 64 positioned between the lid 43 and the drive gear 57 is fixed to the drive shaft 61 via a parallel key 65. The coupling 63 is bolted to the drive shaft 61 and the extension shaft 62 via parallel keys 66 and 67, respectively.

  As shown in FIGS. 7 and 9, the feed cone 7 is formed in a truncated cone shape, and is screwed concentrically with the feed shaft 6 to the tip end portion 6 b of the feed shaft 6. On the conical surface 7c of the feed cone 7, for example, three guide grooves 71 extending in the generatrix direction and formed as dovetail grooves are provided at predetermined intervals in the circumferential direction. An insertion hole 73 for inserting a compression spring (biasing means) 72 is formed on the upper surface of the feed cone 7. The compression spring 72 biases the feed cone 7 downward, and is externally fitted to the feed shaft 6 between the feed cone 7 and the roller holder 53. The number of guide grooves 71 is not particularly limited, and may be two or more. Further, the insertion hole 73 is not essential. Further, the urging means is not limited to the compression spring 72, and various conventionally known techniques can be used.

  As shown in FIGS. 7 and 10, for example, three cutting blade receivers 8 are provided between the cutting blade holder 54 and the ring body 55 disposed at the distal end portion 5 b of the rotary cylinder 5 so as to be movable in the radial direction. It moves slidably on the ring body 55 along the guide groove 59 formed in the radial direction on the lower surface of the cutting blade holder 54. As shown in FIG. 11, the cutting blade receiver 8 is formed in a T shape in plan view. As shown in FIG. 12, a notch 81 is formed on the outer end surface of the cutting blade receiver 8. As shown in FIGS. 7 and 12, an inclined portion 82 that fits into the guide groove 71 of the feed cone 7 is provided on the inner end side of the cutting blade receiver 8. As shown in FIG. 11 and FIG. 12, the inclined portion 82 has a dovetail pattern that has a dovetail-shaped width extending from the outer end side toward the inner end side. Thus, the guide groove 71 of the feed cone 7 and the inclined portion 82 of the cutting blade receiver 8 are connected by a dovetail. The number of cutting blade receivers 8 is not particularly limited, and may be provided according to the number of guide grooves 71 of the feed cone 7.

  As shown in FIG. 7, the cutting blade 9 is provided on the outer end side of the cutting blade receiver 8 so as to be rotatable in a horizontal plane. As shown in FIGS. 11 and 12, the cutting blade 9 protrudes from the outer peripheral surface of a cylindrical cutting blade main body 91. The cutting blade body 91 is inserted into the notch 81 of the cutting blade receiver 8 and is pivotally supported by a rotary shaft 92 provided in the vertical direction on the outer end side of the cutting blade receiver 8.

  As shown in FIG. 10, the rotational drive means 10 rotationally drives the rotary cylinder 5 and the feed shaft 6 in the same direction and the rotational speed of the feed shaft 6 is larger than the rotational speed of the rotary cylinder 5. It is. As shown in FIG. 6, the rotation driving means 10 includes a motor 101, an integrated pinion gear 102, the drive gear 57 and the feed gear 64 described above as main structural members. The motor 101 rotates the integrated pinion gear 102 and is detachably fixed on the lid 43. The integrated pinion gear 102 is rotatably supported with respect to the lid 43 and the support plate 41 of the fixed cylinder 4 so as to protrude upward from the lid 43 by a predetermined length. The integrated pinion gear 102 is integrally provided with a drive pinion gear 103 and a feed pinion gear 104 at predetermined intervals in the vertical direction. The lower drive pinion gear 103 meshes with a drive gear 57 fixed to the rotating cylinder 5. The upper feed pinion gear 104 is meshed with a feed gear 64 fixed to the feed shaft 6. The diameter of the feed pinion gear 104 is larger than the diameter of the drive pinion gear 103, and the number of teeth of the feed pinion gear 104 is larger than the number of teeth of the drive pinion gear 103. The diameter of the feed gear 64 is smaller than the diameter of the drive gear 57, and the number of teeth of the feed gear 64 is smaller than the number of teeth of the drive gear 57. Therefore, if the integrated pinion gear 102 is rotationally driven by the motor 101, the rotary cylinder 5 and the feed shaft 6 are in the same direction and the rotational speed of the feed shaft 6 is the same as that of the rotary cylinder 5 via the drive gear 57 and the feed gear 64. It is rotationally driven so as to be larger than the rotational speed.

  At this time, as shown in FIG. 7, if the male screw 68 formed at the tip 6b of the feed shaft 6 for screwing the feed cone 7 is a right-hand screw, the rotating cylinder 5 and the feed shaft 6 are moved clockwise. To rotate. On the other hand, if the male screw 68 is a left-hand screw, the rotary cylinder 5 and the feed shaft 6 are driven to rotate counterclockwise. In any case, the feed cone 7 rotates at the same rotational speed as that of the rotating cylinder 5 because the inclined portion 82 of the cutting blade receiver 8 is fitted in the guide groove 71, so that the rotational speed of the feed shaft 6 is If the rotary cylinder 5 is rotationally driven so as to be larger than the rotational speed of the rotating cylinder 5, that is, the rotational speed of the feed cone 7, the feed cone 7 moves upward as shown in FIG. As shown in FIG. 2 and FIG. 3, when the cutting blade receiver 8 is pushed and moved outward by this, the cutting blade 9 is pressed against the steel pipe pile 3 from the inside. The cutting blade 9 revolves around the axis of the rotary shaft 92 due to the frictional force with the steel pipe pile 3 while revolving due to the rotation of the rotary cylinder 5. The steel pipe pile 3 is cut from the inside by pressing the cutting blade 9.

  In the cutting machine 1 configured as described above, since the moving mechanism of the cutting blade 9 moved by the feed cone 7 and the cutting blade receiver 8 is relatively simple, there is an advantage that the cost can be reduced.

  When cutting the steel pipe pile 3, as shown in FIGS. 1 and 8, first, the rotating cylinder 5 of the cutting machine 1 is inserted into the steel pipe pile 3 from above so that the head 3 a of the steel pipe pile 3 is inserted. A predetermined length is inserted into the inside of the fixed cylinder 4 from below, and the fixed cylinder 4 is fixed to the outer peripheral surface 3 c of the steel pipe pile 3. At this time, since the fixed cylinder 4 can be fixed to an appropriate height on the ground, there is an advantage that it is not necessary to accurately adjust the protruding length of the steel pipe pile 3 from the ground 2a.

  Here, if the cutting machine 1 is placed on the positioning ring 48 that is externally fitted to the steel pipe pile 3 and fixed to the outer peripheral surface 3c of the steel pipe pile 3 at a predetermined height on the ground, it is larger and heavier than the positioning ring 48. Since it is not necessary to position the cutting machine 1 while supporting it, there is an advantage that the cutting machine 1 can be easily positioned.

  As shown in FIG. 13 and FIG. 14, for example, three fixing bolts 49 are screwed to the positioning ring 48 so as to be in the radial direction and the tip end abuts against the outer peripheral surface 3 c of the steel pipe pile 3. In order to fix the positioning ring 48 to the outer peripheral surface 3c of the steel pipe pile 3, the three fixing bolts 49 are tightened in a state of being externally fitted to the steel pipe pile 3 and supported at a predetermined height on the ground. The number of fixing bolts 49 is not particularly limited, and one or more fixing bolts 49 can be screwed to the positioning ring 48.

  Next, as shown in FIG. 10, the integrated pinion gear 102 is rotationally driven by the motor 101, the rotary cylinder 5 and the feed shaft 6 are in the same direction, and the rotational speed of the feed shaft 6 is higher than the rotational speed of the rotary cylinder 5. Rotate to increase. As shown in FIGS. 2 and 3, the cutting blade 9 is thereby pressed against the steel pipe pile 3 from the inside as described above, so that the steel pipe pile 3 is cut from the inside by the pressing of the cutting blade 9. According to such a method, the steel pipe pile 3 can be cut from the inside using the relatively inexpensive cutting machine 1, and it is not necessary to accurately adjust the protruding length of the steel pipe pile 3 from the ground 2a. Therefore, there exists an advantage that the construction cost of the steel pipe pile 3 can be reduced.

  After the steel pipe pile 3 is cut, the motor 101 is rotated in the reverse direction, the rotating cylinder 5 and the feed shaft 6 are rotated in the counterclockwise direction opposite to the above, and the rotation speed of the feed shaft 6 is higher than the rotation speed of the rotating cylinder 5. If the rotational drive is performed so that it becomes larger, the feed cone 7 returns downward. At this time, since the guide groove 71 of the feed cone 7 and the inclined portion 82 of the cutting blade receiver 8 are connected by a dovetail joint, the cutting blade receiver 8 returns inward by the downward movement of the feed cone 7 and is cut. The blade 9 is accommodated in the steel pipe pile 3. Thus, if the guide groove 71 of the feed cone 7 and the inclined portion 82 of the cutting blade receiver 8 are connected by a dovetail joint, the cutting blade 9 can be accommodated inside the steel pipe pile 3 by the simple operation as described above. There is an advantage that you can.

  If the feed shaft 6 is manually rotated counterclockwise by a wrench or the like instead of rotating the motor 101 in the reverse direction, the rotating cylinder 5 is also connected via the feed gear 64, the integrated pinion gear 102, and the drive gear 57. Rotates counterclockwise. Also in this case, the rotary cylinder 5 and the feed shaft 6 rotate so that the rotation speed of the feed shaft 6 is larger than the rotation speed of the rotary cylinder 5 and the feed cone 7 returns downward. It can be accommodated inside the pile 3. Here, as shown in FIG. 6, if a wrench projection 69 for rotating the feed shaft 6 with a wrench is provided on the end face of the head 6a of the feed shaft 6, the feed shaft 6 can be easily rotated. There is an advantage that can be. The same applies when a wrench hole (not shown) for inserting a hexagon wrench or the like is provided on the end face of the head 6a of the feed shaft 6.

  Next, as shown in FIG. 15, if the steel pipe 35 after cutting is removed after removing the cutting machine 1 and the positioning ring 48, the cutting operation is completed. The opening 36 of the head 3a of the steel pipe pile 3 after cutting may be closed with an appropriate temporary cap (not shown). The steel pipe 35 after cutting may be removed with the cutting machine 1 and the positioning ring 48 attached. In this case, since the protruding length of the cutting blade 9 outward from the outer peripheral surface 3c of the steel pipe pile 3 is small, the steel pipe 35 after cutting may be removed without returning the cutting blade 9 inward.

  In the cutting machine 1, as shown in FIG. 2, when the feed cone 7 moves upward by a predetermined distance, the threaded engagement between the female screw 74 of the feed cone 7 and the male screw 68 of the feed shaft 6 is released. 7 does not move upward any further. Therefore, if a compression spring 72 for biasing the feed cone 7 downward is provided, even if the screwing is released, the operation of returning the feed cone 7 downward by the motor 101 or manually as described above is performed. There is an advantage that the screwing can be immediately restored.

  Here, if a guide roller 111 formed in a cylindrical shape so as to be inscribed in the steel pipe pile 3 is provided in the distal end portion 5b of the rotating cylinder 5 so as to be slidable in the circumferential direction, the guide inscribed in the steel pipe pile 3 is provided. Since the rotary cylinder 5 can be slidably rotated with respect to the roller 111, there is an advantage that the shake at the time of rotation of the rotary cylinder 5 can be prevented.

  The steel pipe pile cutting machine and cutting method according to the present invention are suitable for reducing the cost as well as not having to adjust the protruding length of the steel pipe pile upward from the ground.

The longitudinal cross-sectional view which shows the use condition of the cutting machine which concerns on embodiment. The principal part expansion longitudinal cross-sectional view which shows the state after cut | disconnecting a steel pipe pile from the inside. The principal part expanded cross-sectional view which shows the state after cut | disconnecting a steel pipe pile from the inside. The longitudinal cross-sectional view which shows the state which carried out the rotation penetration of the steel pipe pile in the ground. The longitudinal cross-sectional view which shows the state after cutting and removing the unnecessary part of a steel pipe pile. The principal part expansion longitudinal cross-sectional view which shows the use condition of a cutting machine. The principal part expansion longitudinal cross-sectional view which shows the use condition of a cutting machine. The longitudinal cross-sectional view which shows a mode that a cutting machine is installed. The top view of a feeding cone. The principal part expanded horizontal sectional view which shows the use condition of a cutting machine. The top view of the cutting blade receiver which provided the cutting blade. The front view of the cutting blade receiver which provided the cutting blade. The principal part expansion longitudinal cross-sectional view which shows the state which fixed the positioning ring externally fitted to the steel pipe pile to the outer peripheral surface of the steel pipe pile at predetermined height on the ground. AA line sectional view of Drawing 13. The principal part expansion longitudinal cross-sectional view which shows a mode that the steel pipe after a cutting | disconnection is removed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cutting machine 2 Ground 3 Steel pipe pile 3a Head 3c Outer peripheral surface 4 Fixed cylinder 4b Lower edge part 4d Inner peripheral surface 45 Guide collar 48 Positioning ring 5 Rotating cylindrical body 5b Tip 6 Feed shaft 6b Tip 7 Feed cone 7c Cone Surface 71 Guide groove 72 Compression spring (biasing means)
8 Cutting blade receiver 82 Inclined portion 9 Cutting blade 10 Rotation drive means

Claims (6)

A cutting machine for cutting a steel pipe pile penetrating into the ground from the inside,
A fixed cylindrical body that is formed in a substantially cylindrical shape and is fixed concentrically with the steel pipe pile on the outer peripheral surface of the steel pipe pile so as to insert the head of the steel pipe pile into the predetermined length from below.
A rotating cylinder formed in a substantially cylindrical shape and supported in the fixed cylinder so as to be rotatable about its axis and to protrude downward from a lower edge of the fixed cylinder;
A feed shaft supported in the rotating cylinder so as to be rotatable around the axis of the fixed cylinder and to protrude downward from a lower edge of the fixed cylinder by a predetermined length;
A feed cone formed in a truncated cone shape, screwed concentrically with the feed shaft at the tip of the feed shaft, and provided with a plurality of guide grooves extending in the generatrix direction on the conical surface;
A cutting blade receiver that is provided at the distal end portion of the rotating cylinder so as to be movable in the radial direction and provided with an inclined portion that fits into the guide groove of the feed cone on the inner end side;
A cutting blade provided rotatably on the outer end side of the cutting blade receiver in a horizontal plane;
Rotation drive means for rotating the rotation cylinder and the feed shaft in the same direction and rotating the feed shaft so that the rotation speed of the feed shaft is larger than the rotation speed of the rotation cylinder;
A steel pipe pile cutting machine characterized by comprising:   The steel pipe pile cutting machine according to claim 1, wherein a guide groove of the feed cone and an inclined portion of the cutting blade receiver are connected by a dovetail joint.   The steel pipe pile cutting machine according to claim 1 or 2, further comprising biasing means for biasing the feed cone downward.   The steel pipe pile cutting machine according to any one of claims 1 to 3, further comprising a ring-shaped guide collar interposed between an inner peripheral surface of the fixed cylindrical body and an outer peripheral surface of the steel pipe pile. The steel pipe pile cutting machine according to any one of claims 1 to 4, wherein the steel pipe pile penetrated into the ground is cut from the inside,
Insert the rotary cylinder body into the steel pipe pile from above and insert the steel pipe pile head from below into the fixed cylinder body for a predetermined length,
Fixing the fixed cylinder to the outer peripheral surface of the steel pipe pile;
Cutting a steel pipe pile, wherein the rotary driving unit drives the rotary cylinder and the feed shaft in the same direction so that the rotational speed of the feed shaft is larger than the rotational speed of the rotary cylinder. Method.   The cutting method of the steel pipe pile of Claim 5 which mounts the said cutting machine on the positioning ring externally fitted to the said steel pipe pile, and was fixed to the outer peripheral surface of the said steel pipe pile at predetermined height on the ground.

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