JP5244061B2 - Bit exchanging device for shield excavator - Google Patents

Description

  The present invention relates to an apparatus for exchanging a bit provided in a cutter head of a shield excavator for cutting a natural ground.

  The shield excavator generally includes a cutter head that is driven to rotate about an axis parallel to the excavation direction, and a bit for cutting a natural ground is attached to the cutter head. Since such a bit is worn by cutting a natural ground, it is necessary to take measures such as bit replacement in long-distance construction.

  2. Description of the Related Art Conventionally, a method is generally employed in which an operator moves to the face side and replaces a bit after the front face is hardened by chemical injection or the like. When a worker goes out to the face side and replaces a bit, there are various problems such as an increase in construction cost and a prolonged work period due to chemical injection or the like.

  In view of this, many bit exchange devices have been proposed that allow bits to be exchanged without workers coming to the face side (see Patent Documents 1 to 3).

JP 2001-27097 A JP 2002-357084 A JP 2008-63780 A

  However, many of the proposed bit changers have a complicated structure, and many of them have low reliability in operation under high water pressure and earth and sand atmosphere.

  Accordingly, an object of the present invention is to provide a bit exchanging device for a shield excavator having a simple structure and high reliability in operation under high water pressure and earth and sand atmosphere.

  In order to achieve the above object, the present invention provides an apparatus for exchanging a bit provided in a cutter head of a shield excavator for cutting a natural ground, wherein a bit is inserted from the cutter head provided in the cutter head. A housing having a through hole for accommodating the tip of the bit so as to protrude toward the face, and a bit that has been worn on a new bit when the bit detachably provided on the housing and worn toward the face is worn. An extruding device that pushes a worn bit by pushing a new bit in the forward direction of the through hole by taking a reaction force from the housing in a state of being pressed against the rear part, and detachable from the housing A first reaction force member that transmits a reaction force of the extrusion device to the housing when a new bit is pushed into the through hole by the extrusion device; In which a new bit is pushed into the through hole at removably provided the extrusion apparatus Managing has a second reaction force member for supporting the rear part of the new bit to not retract.

  According to the present invention, there is an excellent effect that it is possible to provide a bit exchanging device for a shield excavator having a simple structure and high reliability in operation under high water pressure and earth and sand atmosphere.

FIG. 1 is a side sectional view of a shield excavator provided with a bit exchange device according to an embodiment of the present invention. 2A is a side sectional view of the bit exchange device, and FIG. 2B is a view taken along the line AA in FIG. 2A and a view taken along the line BB in FIG. 2A. is there. FIG. 3 is a perspective view of the bit exchange device. FIG. 4A to FIG. 4D are diagrams showing a bit exchange procedure. FIGS. 5E to 5H are diagrams showing a bit exchange procedure.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the shield excavator 1 is rotatable about a cylindrical shield frame 2, a partition 3 that divides the shield frame 2 into front and rear in the digging direction, and an axis parallel to the digging direction. The shield frame 4 is supported by the supported cutter head 4, the erector (not shown) for assembling the segments in the shield frame 2 in a ring shape, and the reaction force applied to the segments assembled in the ring shape on the inner surface of the shield frame 2. 2 and a shield jack (not shown) for advancing 2.

  The cutter head 4 has a central portion 5 rotatably supported by the partition wall 3 and a plurality of cutter spokes 6 radially attached to the central portion 5 at intervals in the circumferential direction. And the like, and the like are rotated around an axis parallel to the excavation direction. A fishtail bit 7 is attached to the central portion 5, and a plurality of bits 8 are arranged on the cutter pork 6 at intervals in the radial direction of the cutter head 4.

  The fishtail bit 7 and the bit 8 are pressed against the natural ground by extending the shield jack, and the ground is cut by rotating the cutter head 4 in this state.

  The cutter head 4 is a spoke type in this embodiment, but may be a face plate type.

  As shown in FIG. 1, a plurality of bit exchange devices 10 are provided in alignment with the cutter pork 6.

  As shown in FIGS. 2 and 3, the bit exchange device 10 is provided in the cutter head 4 (the cutter spoke 6 in this embodiment) so as to open to the front surface F thereof, and inserts the bit 8 from within the cutter head 4. A housing 12 having a through-hole 11 for accommodating the tip of the lever so as to protrude toward the face, and a removable bit 8 provided when the bit 8 protruding toward the face is worn. Extruding device 13 for pushing out the worn bit 8 by pushing the new bit 8 in the forward direction of the through hole 11 by taking a reaction force from the housing 12 while pressed against the rear portion of the bit 8. And a first reaction force member that is detachably provided in the housing 12 and transmits the reaction force of the extrusion device 13 to the housing 12 when the new bit 8 is pushed into the through hole 11 by the extrusion device 13. 4 and a second reaction member 15 that is detachably provided on the housing 12 and supports the rear portion of the new bit 8 so that the new bit 8 pushed into the through hole 11 by the extrusion device 13 does not move backward. Yes.

  The through hole 11 of the housing 12 is formed in an oval shape (or an oval shape) (see FIG. 2B). A stud bolt 16 is provided at the front end of the housing 12 so as to extend rearward from the front end. A plurality of ears 17 are provided at the rear end of the housing 12 so as to protrude from the rear end outward in the radial direction of the through hole 11.

  The bit 8 is inserted into the through hole 11 so as to be movable along the front-rear direction of the through hole 11, and extends from the base 18 to the front of the through hole 11, and has a smaller diameter than the base 18. A small-diameter portion 19, and a main body portion 20 provided to extend from the small-diameter portion 19 in the forward direction of the through hole 11 and to which a cemented carbide chip (not shown) is attached. A ring-shaped seal 21 that seals the gap between the inner periphery of the through hole 11 and the outer periphery of the pedestal 18 is provided on the outer periphery of the pedestal 18. The pedestal 18 is formed in an elliptical cross section (or an oval cross section) (see FIG. 2B), and the bit 8 is formed in the through hole by the outer peripheral surface of the pedestal 18 contacting the inner peripheral surface of the through hole 11. 11 is prevented from rotating around the longitudinal axis. The pedestal 18 is provided with a concave portion 22 for accommodating the main body portion 20 of the bit 8 disposed behind the bit 8, and the main body portion 20 of the rear bit 8 is accommodated in the concave portion 22 of the front bit 8. In this state, by pushing the rear bit 8 in the forward direction of the through hole 11, the front bit 8 is moved in the forward direction of the through hole 11 by the rear bit 8. Further, the base 18, the small diameter portion 19, and the main body portion 20 are provided with a rod insertion hole 24 through which a rod 23 described later can be inserted, and the female insertion screw 24 is provided at the tip of the rod insertion hole 24. A portion 25 is provided.

  In this embodiment, two bits 8 are accommodated in series in the through holes 11 of each housing 12.

  The extrusion device 13 has a rod 23 inserted into the rod insertion hole 24 of the bit 8 and a center hole jack 26 (see FIG. 4D, etc.) for moving the bit 8 along the through hole 11. ing. A distal-end-side male screw portion 27 is provided at the distal end portion of the rod 23, and the distal-end-side male screw portion 27 is screwed into a female screw portion 25 provided in the main body portion 20 of the bit 8 protruding to the face side. ing. Further, a rear end side male screw portion 28 is provided at the rear end portion of the rod 23. The center hole jack 26 has an outer cylinder part 29 formed in a cylindrical shape, and an inner cylinder part 30 inserted through the outer cylinder part 29 so as to be movable along the longitudinal direction of the outer cylinder part 29 and engageable with the rod 23. (See FIG. 4D and the like).

  The first reaction force member 14 is a rectangular plate-shaped lid portion 31 (see FIG. 2A) that closes the intermediate portion in the width direction of the through hole 11, and extends from the lid portion 31 in the forward direction of the through hole 11. A pair of extending portions 32 that sandwich the housing 12 from the radially outer side of the through hole 11, and an ear portion 33 that extends from each extending portion 32 to the radially outer side of the through hole 11. And have. A bolt insertion hole 34 is formed in the lid portion 31, and the rod 23 is inserted through the bolt insertion hole 34. By tightening the lock nut 35 from the rear to the rear end side male thread portion 28 of the rod 23, the rod 23 and the lock nut 35 are used to restrict the bit 8 protruding to the face side from moving in the forward direction of the through hole 11. ing. Further, a bolt insertion hole 36 is formed in the ear portion 33, and the stud bolt 16 is inserted into the bolt insertion hole 36. By tightening the nut 37 to the stud bolt 16 from the rear, the first reaction force member 14 is restricted by the nut 37 from moving in the rearward direction of the through hole 11.

  The second reaction material 15 includes a pair of semicircular plate-shaped lid portions 38 (see FIG. 2B) that respectively close the end portions in the width direction of the through holes 11, and the diameter of the through holes 11 from the respective lid portions 38. And a plurality of ears 39 formed so as to protrude outward in the direction. The second reaction force member 15 is attached to the housing 12 by fastening the ear portion 17 of the housing 12 and the ear portion 39 of the second reaction force member 15 with a bolt 40.

  Next, the bit exchange procedure will be described with reference to FIGS.

  When the bit 8 is replaced, after the cutter head 4 is stopped, an operator enters the work space S (see FIGS. 1 and 4A) in the cutter pork 6 and each of the cutter pork 6 is provided. Bit 8 of the bit exchange device 10 is exchanged. In the present embodiment, the center portion 5 of the cutter head 6 is formed hollow and a manhole is provided in the center portion 5, and an operator enters the work space S in the cutter pork 6 through the manhole. Yes. In the state shown in FIG. 4A, the bit 8 is supported by the first reaction force material 14 and the second reaction force material 15 so as not to retreat.

  First, as shown in FIG. 4B, the lock nut 35 is removed from the rod 23 and the first reaction material 14 is removed from the housing 12. By removing the first reaction force member 14, the bit 8 is supported by the second reaction force member 15 so as not to retreat.

  Next, as shown in FIG. 4C, the rod 23 is pulled out from the bit 8 protruding to the face side and engaged with the bit 8 disposed behind the bit 8 protruding to the face side. Then, another bit 8 is arranged behind the bit 8 that is previously accommodated in the through hole 11. Thereafter, the first reaction force member 14 is attached to the housing 12 again.

  Next, as shown in FIG. 4 (d), the addition portion 41 is added to the rod 23, and the center hole jack 26 is attached to the first reaction force member 14. Thereafter, the nut 37 is fastened to the stud bolt 16 in a state where the front surface of the lid portion 31 of the first reaction force member 14 is in contact with the rear end of the bit 8 arranged at the rearmost position.

  Next, as shown in FIG. 5 (e), the center hole jack 26 is extended and fixed to the rod 23. Thereafter, the second reaction force material 15 is removed from the housing 12. By removing the second reaction force member 15, the bit 8 is supported by the center hole jack 26 and the first reaction force member 14 so as not to retreat.

  Next, as shown in FIG. 5 (f), the center hole jack 26 is contracted and the bit 8 is pushed in the forward direction of the through hole 11, so that the worn bit 8 protruding toward the face is moved forward of the through hole 11. Move to. Then, when the center hole jack 26 is contracted to the most retracted state or a state close thereto, in order to replace the center hole jack 26, the front surface of the lid portion 38 of the second reaction force member 15 is disposed at the rearmost position. The second reaction force member 15 is attached to the housing 12 using the bolt 40 in a state where the second reaction force member 15 is in contact with the rear portion. By attaching the second reaction force member 15, the bit 8 is supported by the second reaction force member 15 so as not to move backward.

  Next, as shown in FIG. 5 (g), the first reaction force member 14 is moved in the forward direction of the through hole 11 to the position of the second reaction force member 15, and the nut 37 is further tightened. 5 (e) to 5 (g) until the worn bit 8 protruding toward the face is pushed forward of the through hole 11 and the tip of the rear bit 8 protrudes toward the face. Repeat the procedure.

  Then, as shown in FIG. 5 (h), if the worn bit 8 protruding to the face side is pushed forward of the through hole 11 and the tip of the rear bit 8 protrudes to the face side, The hole jack 26 is removed from the first reaction force member 14 and the splicing portion 41 is removed from the rod 23. Then, the lock nut 35 is fastened to the rod 23, and the replacement work of the bit 8 is completed.

  As described above, according to the present embodiment, the bit 8 can be reliably replaced by a simple operation of pushing the worn bit 8 forward of the through hole 11, so that the operator can inject the chemical solution and the like Compared with the case where the bit 8 is replaced and the bit 8 is exchanged, it is possible to effectively suppress an increase in construction cost and a prolonged work period.

  Further, in the present embodiment, a method of supporting the bit 8 with the second reaction force material 15 so as not to move backward is adopted, and it is necessary to provide a bit 8 retracting prevention mechanism (see Patent Document 2) such as a ratchet, for example. The structure is very simple, and the operation reliability is high under high water pressure and earth and sand atmosphere.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various other embodiments can be adopted.

  For example, when the long stroke extrusion device 13 (center hole jack 26) is employed or when the height of the bit 8 may be low, replacement of the extrusion device 13 (center hole jack 26) becomes unnecessary.

  Further, although the bit exchange device 10 is provided in the cutter pork 6, it is not limited to this. The bit exchange device 10 may be provided at any position of the cutter head 4, for example, at the central portion 5.

  Further, although the through hole 11 is formed in an elliptical shape (or oval shape) and the base 18 of the bit 8 is formed in an elliptical cross section (or oval shape in cross section), this is not restrictive. The through hole 11 and the pedestal 18 of the bit 8 may have any shape as long as the rotation of the bit 8 can be prevented, and may have another shape as long as it is non-circular.

DESCRIPTION OF SYMBOLS 1 Shield excavator 4 Cutter head 8 Bit 10 Bit exchange apparatus 11 Through-hole 12 Housing 13 Extrusion apparatus 14 1st reaction force material 15 2nd reaction force material

Claims (1)

  In an apparatus for exchanging a bit for cutting a natural ground provided in a cutter head of a shield excavator, a bit is inserted from the cutter head provided in the cutter head, and a tip end portion of the bit protrudes to a face side. The housing has a through-hole to be accommodated, and a reaction force from the housing in a state where a new bit is pressed against the rear part of the worn bit when the bit detachably provided on the housing is worn away and worn. An extruding device for pushing the worn bit by pushing a new bit in the forward direction of the through hole to the front of the through hole, and a new bit detachably provided in the housing by the extruding device. A first reaction force member that transmits the reaction force of the extrusion device to the housing when being pushed into the through hole; Bit changer shield excavator, characterized in that the new bit is pushed into the through hole in the location has a second reaction force member for supporting the rear part of the new bit to not retract.

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