JP2010031523A - Vertical shaft excavator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft excavator capable of reliably transmitting a torque and a pressing force from a rotating press-fitting device to a Kelly bar when a shaft is constructed in a ground by an earth drill work method. <P>SOLUTION: This vertical shaft excavator includes: the Kelly bar 5; a holding member 80 capable of rotating a cylindrical casing 11 while holding from the outer peripheral side; the rotating press-fitting device 7 having a vertical movement drive means 74 for vertically moving the holding member 80; a rotating transmission device 9 which comprises a boss part 91 into which the Kelly bar 5 is inserted slidably in the axial direction and a connection part 93 connected to the holding member 80 detachably from the upper side and which is rotatable integrally with the Kelly bar 5; and a fixing means having a fixing pin 53 capable of fixing the axial slide of the Kelly bar 5 relative to the rotating transmission device 9. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a shaft excavator used for excavating the ground to provide a shaft, and more particularly to a shaft excavator used in an earth drill method.

  Conventionally, an earth drill method is known as a method for providing a cast-in-place pile in the ground. In this earth drill method, first, the cylindrical casing for preventing collapse of the shaft wall of the shaft is rotated or swung by the rotary press-fitting device, and the cylindrical casing is moved up and down by a jack or the like provided on the rotary press-fitting device. And move it to a certain depth in the ground. After that, the drill bucket attached to the tip of the drill bucket is inserted into the cylindrical casing in a state suspended from the boom of the mobile crane, and the drill bucket is rotated while the kelly bar is rotated by the kelly bar drive provided on the boom or the like. While excavating by the method, the earth and sand are discharged out of the cylindrical casing to form a shaft. After this, after reinforced rods were built into the shaft, the treme tube was inserted into the shaft, and the concrete was poured into the shaft, and then the cylindrical casing was pulled out. As a result, cast-in-place piles are provided.

Here, conventionally, a plurality of shaft excavators configured so as to be able to transmit the rotational torque transmitted to the cylindrical casing by the rotary press-fitting device to the kelly bar have been proposed (for example, Patent Documents 1 to 3). reference.). As a result, it is not necessary to separately provide a device such as a kelly bar drive or a heavy machine for rotating the kelly bar, and the operation can be simplified.
JP 58-20892 A Japanese Unexamined Patent Publication No. 63-19328 JP 2004-52294 A

  By the way, the shaft excavator disclosed in Patent Documents 1 to 3 proposed in the prior art is specialized in a configuration that can transmit the rotational torque from the rotary press-fitting device to the Keriba to the last, such as a jack of the rotary press-fitting device, etc. However, sufficient studies have not been made on a configuration that can reliably transmit the pushing force due to the vertical movement of the knives to the Keriva.

  For example, Patent Document 1 discloses a configuration in which the rotational torque from the rotary press-fitting device can be transmitted to the kelly bar via the yoke, and the yoke and the kelly bar are simply in the through hole formed in the yoke. It is set as the structure which only inserts.

  For this reason, the pushing force obtained from the rotary press-fitting device is somewhat transmitted by the frictional force between the through hole of the yoke and the kelly bar, but when excavating a hard ground such as a support layer with a drill bucket, There is a problem in that the kelly bar moves with respect to the yoke so as to slide in the axial direction, and the pushing force from the rotary press-fitting device is not sufficiently transmitted.

  In addition, when the pushing force from the rotary press-fitting device is transmitted by the frictional force between the yoke through-hole and the kelly bar, a gap may be formed between the yoke through-hole and the kelly bar due to manufacturing errors, etc. In this case, water may accumulate between the through-hole of the yoke and the kelly bar, and there is a possibility that the pushing force from the rotary press-fitting device cannot be reliably transmitted.

  Neither Patent Document 2 nor Patent Document 3 specifically discloses a configuration in which the kelly bar and the yoke are coupled so as to fix the movement of the kelly bar in the axial direction, and the rotational torque from the rotary press-fitting device does not penetrate the yoke. It is thought that it is transmitted by the frictional force between the hole and the Keriba, and it is considered that these disclosed techniques have the same problems as described above.

  Accordingly, the present invention has been devised in view of the above-described problems, and the object of the present invention is to make a shaft excavation capable of reliably transmitting the rotational torque and the pushing force from the rotary press-fitting device to the kelly bar. Is to provide a machine.

  In order to solve the above-described problems, the present inventor has invented the following resisting excavator after intensive studies.

  A resisting excavator according to claim 1 of the present invention is inserted into a crane provided with a boom and a cylindrical casing embedded in the ground in a state of being suspended from the boom, with a drill bucket at the lower end. Is attached along the circumferential direction around the axis of the kelly bar, and is configured to rotate the cylindrical casing while gripping the cylindrical casing from the outer peripheral side. A rotary press-fitting device having an up-and-down movement drive means, a boss portion through which the kelly bar is slidably inserted in the axial direction, and a plurality of boss portions around the axis of the boss portion. A rotation transmission device having a coupling portion to be coupled and configured to be rotatable integrally with the kelly bar, and fixing the slide in the axial direction of the kelly bar with respect to the rotation transmission device Characterized in that it comprises a potential fixing means.

  In the resist excavator according to claim 2 of the present invention, in the invention according to claim 1 of the present application, the boss portion of the rotation transmission device is formed of a cylindrical body, and the fixing means includes the cylindrical body and the kelly bar. It is composed of a fixed pin that penetrates.

  According to a third aspect of the present invention, in the invention according to the first or second aspect of the present invention, the rotary press-fitting device projects from the upper part of the gripping member and is movable at the upper end and can be rotated around the projecting direction. The rotation transmitting device is attached to and detached from the gripping member by rotating a movable portion of the twist lock pin inserted in a pin hole formed in the connecting portion. It is connected so that it is possible.

  In the invention according to claim 4 of the present invention, in the invention according to any one of claims 1 to 3, the crane is configured to be capable of self-propelling, and the rotary press-fitting device is By being connected by a pin structure with a horizontal pin, it is configured to be rotatable about the connecting portion.

  The shaft excavator according to claim 5 of the present invention is characterized in that, in the invention according to claim 4 of the present application, the boom of the crane is configured to be extendable and contractable in the axial direction.

  According to the first aspect of the present invention, the mode in which only the rotational torque of the rotary press-fitting device 7 is transmitted to the kelly bar 5 and the excavation work can be performed quickly, and the rotary torque and the pushing force of the rotary press-fitting device 7 are determined. Thus, it is possible to perform excavation work by properly using the configuration in which the excavation performance is improved by reliably transmitting to 5 with a simple configuration, and the work efficiency during excavation work is excellent.

  According to the third aspect of the present invention, the rotational torque generated by the swinging motion of the gripping member 80 can be reliably transmitted to the kelly bar 5 via the rotation transmission device 9.

  According to the invention of claim 4 of the present application, the rotary press-fitting device 7 can be easily transported to the site and removed from the site. This eliminates the need for a special heavy machine or the like for installing the rotary press-fitting device 7 and improves the working efficiency.

  According to the invention according to claim 5 of the present application, when the rotary press-fitting device 7 is transported to the site, the tip of the boom 35 is less likely to be caught with respect to an overhead wire such as an electric wire installed between a utility pole or a steel tower, It becomes possible to carry the rotary press-fitting device 7 to and from the site by the mobile crane 3 more easily.

  Hereinafter, as a best mode for carrying out the present invention, a shaft excavator used for excavating the ground to provide a shaft will be described in detail with reference to the drawings.

  FIG. 1 is a side view showing the overall configuration of the shaft excavator 1. FIG. 1A shows a state before the kelly bar 5 constituting the resisting excavator 1 is inserted into the cylindrical casing 11 buried in the ground, and FIG. 1B shows the inside of the cylindrical casing 11. Shows the state after the Keriba 5 is inserted. The cylindrical casing 11 is used in the cast-in-place pile method or the like, and prevents the collapsed hole wall from collapsing when buried in the ground, and is made of a steel pipe.

  The shaft excavator 1 includes a mobile crane 3, a Kelly bar 5, a rotary press-fitting device 7, and a rotation transmission device 9.

  The mobile crane 3 includes a self-propelled lower traveling body 31 and an upper revolving body 33 that is connected to the lower traveling body 31 and is provided so as to be capable of turning around a vertical axis.

  FIG. 2 is a schematic plan view showing the configuration of the lower traveling body 31 of the mobile crane 3. In the lower traveling body 31, side frames 31b are fixed to the left and right of the main frame 31a, and a caterpillar 31c that operates using a hydraulic motor or the like as a drive source is wound around the outer periphery of the side frame 31b. It is configured.

  As shown in FIG. 1, the upper swing body 33 is attached with a boom 35 pivotally supported so as to be tiltable about a shaft 35 b at the upper portion thereof. The boom 35 is configured to be extendable in the axial direction in multiple stages based on various drive sources. A wire rope 37 is suspended from the tip of the boom 35 via a plurality of sheaves 35a that function as a fixed pulley. One end side of the wire rope 37 is fixed in a state where it can be wound and fed out by a winch 39 mounted on the upper swing body 33. The other end side of the wire rope 37 is stretched over a sheave block 43 that functions as a moving pulley, and is fixed to a fastener 41 provided at the tip of the boom 35. The kelly bar 5 is suspended from the tip of the boom 35 via a wire rope 37 and a sheave block 43.

  FIG. 3 is a side view showing the configuration of the kelly bar 5 and the rotation transmission device 9, and FIG. 4 is a cross-sectional view taken along line AA of FIG. A drill bucket 51 as a drilling tool for performing a drilling operation is detachably attached to the lower end portion of the kelly bar 5. As shown in FIG. 4, the kelly bar 5 is formed in a prismatic shape having a square cross section in the present embodiment, and a plurality of pin holes 55 are spaced apart in the axial direction as shown in FIG. Is formed.

  The kelly bar 5 is suspended so as to be movable up and down by winding and unwinding the wire rope 37 by the winch 39 and extending and retracting the boom 35, and is buried in the ground as shown in FIGS. 1 (a) and 1 (b). The cylindrical casing 11 is inserted into the cylindrical casing 11 while being suspended from the boom 35.

  FIG. 5 is a side view showing the configuration of the rotary press-fitting device 7, and FIG. 6 is a plan view thereof. The rotary press-fitting device 7 includes a base frame 71, a lifting frame 73 provided on the base frame 71, and a rotating frame 75 provided on the lifting frame 73. An opening 77 penetrating in the vertical direction is formed at substantially the center of the base frame 71, the lifting frame 73, and the rotating frame 75. The cylindrical casing 11 can be inserted into the opening 77.

  The base frame 71 is provided with a plurality of leg portions 72 on the side thereof, and is placed on the ground surface via the plurality of leg portions 72. The base frame 71 is provided with a vertically moving cylinder 74 such as a hydraulic cylinder as a vertically moving driving means for vertically moving the lifting frame 73 around the opening 77. As shown in FIG. 7, the elevating frame 73 and the rotating frame 75 are raised or lowered according to the extension or contraction of the vertical movement cylinder 74.

  The rotating frame 75 is provided with a grip member 80 for gripping the cylindrical casing 11 inserted through the opening 77 at the upper portion thereof. The holding member 80 is disposed along the circumferential direction of the cylindrical casing 11, that is, along the circumferential direction around the axis of the kelly bar 5 inserted into the cylindrical casing 11 and spaced from the kelly bar 5. become.

  The gripping member 80 includes an arcuate fixed segment 81 fixed to the elevating frame 73 and a moving segment 83 having one end connected to both ends of the fixed segment 81 by pin coupling. ing. Each moving segment 83 is configured to be rotatable about a vertical axis around a connecting portion with the fixed segment 81. Each moving segment 83 is connected to the main body side and the rod side of an open / close cylinder 85 such as a hydraulic cylinder by pin coupling at the other end side. Each moving segment 83 is configured to be rotatable around a vertical axis around a connecting portion between the main body side and the rod side of the open / close cylinder 85.

  The gripping member 80 having such a configuration can be opened radially outward by the extension of the opening / closing cylinder 85 and can be closed radially inward by the contraction of the opening / closing cylinder 85. When the cylindrical casing 11 is placed in the ground, the cylindrical casing 11 can be gripped from the outer peripheral side by closing the gripping member 80, and the cylindrical casing 11 is opened by opening the gripping member 80. Can be released.

  The elevating frame 73 is provided with a rotation motor 76 as a rotation driving means for rotating the rotation frame 75 at the upper part thereof. The rotary frame 75 is configured to be rotatable or swingable around the vertical axis with the rotary motor 76 as a drive source. Thereby, the holding member 80 is configured to be rotatable or swingable in a state where the cylindrical casing 11 is held from the outer peripheral side.

  When the cylindrical casing 11 is embedded in the ground by the rotary press-fitting device 7, the rotary table 75 is rotated and swung while the cylindrical casing 11 is gripped by the gripping member 80, and the vertical movement is performed by the vertical movement cylinder 74. As a result, the cylindrical casing 11 is buried in the ground. The rotary press-fitting device 7 can resist a reaction force from the ground loaded on the rotary press-fitting device 7 itself when the cylindrical casing 11 and the kelly bar 5 are lowered by the vertical movement cylinder 74. A counterweight (not shown) is provided.

  The rotary press-fitting device 7 includes a twist lock pin 87 for enabling the gripping member 80 provided on the rotary press-fitting device 7 to be detachably connected to the rotation transmission device 9. In the present embodiment, the twist lock pins 87 are provided at four positions at a pitch of 90 ° at intervals in the circumferential direction of the gripping member 80.

  The twist lock pin 87 is provided so as to protrude upward from the pin base 89 provided on the fixed segment 81 and the moving segment 83 constituting the gripping member 80, and can be rotated around the protrusion direction at the upper end thereof. A movable portion 87b is provided. The twist lock pin 87 includes a fixed portion 87 a provided on the pin base 89 and a movable portion 87 b provided on the fixed portion 87 a, and an operation lever 87 c provided on the pin base 89. By this operation, the movable portion 87b can be rotated around its protruding direction, that is, around the vertical axis while the fixed portion 87a remains fixed.

  As shown in FIG. 6, the fixed portion 87 a and the movable portion 87 b of the twist lock pin 87 are adjusted so as to have substantially the same shape in plan view when not connected to the rotation transmission device 9. . A tapered surface that is sharpened toward the upper end is formed on the upper surface of the movable portion 87b.

  As shown in FIGS. 3 and 4, the rotation transmission device 9 includes a boss portion 91 into which the kelly bar 5 is slidably inserted in the axial direction thereof, and a plurality of rotation transmission devices 9 provided at intervals around the vertical axis of the boss portion 91. Part 93.

  The boss portion 91 is constituted by a cylindrical body in which a fitting hole 91 a having substantially the same shape as the outer shape of the Kelly bar 5 is formed. The rotation transmission device 9 is fixed to a lower portion of a boss portion 91 configured as a cylindrical body in a state where a disc 97 in which a hole into which the kelly bar 5 can be inserted is formed is inserted around the boss portion 91. Further, a reinforcing plate 95 having a T-shaped cross section is fixed on the circular plate 97 so as to extend radially outward with the boss portion 91 as a center, and at the tip of the reinforcing plate 95 radially outside of the circular plate 97, A box-like box body 99 whose lower side is opened is fixedly configured.

  The rotation transmission device 9 is configured to be integrally rotatable around the axis of the kelly bar 5 by fitting the fitting hole 91 a of the boss portion 91 with the kelly bar 5.

  The cylindrical body constituting the boss portion 91 is formed with two pin holes 91b penetrating therethrough so as to be aligned on the horizontal axis. The pin hole 91b provided in the cylindrical body constituting the boss portion 91 and the pin hole 55 of the kelly bar 5 are fixed as fixing means capable of fixing the slide in the axial direction of the kelly bar 5 with respect to the rotation transmitting device 9. The pin 53 is penetrated.

  A male screw is formed on one end side of the fixing pin 53, and an end plate 53a for preventing the fixing pin 53 from coming out of the pin holes 55 and 91b is provided on the other end side of the fixing pin 53. The fixing pin 53 configured as described above is passed through the pin hole 55 and the pin hole 91b, and then a female screw member such as a nut is screwed into the male screw of the fixing pin 53, so that the fixing pin 53 is fixed. In other words, the fixing pin 53 is detachably attached to the rotation transmission device 9 and the kelly bar 5.

  Accordingly, when the fixing pin 53 is not used for fixing, the kelly bar 5 is slidable in the axial direction with respect to the boss portion 91. When the fixing pin 53 is used for fixing, the kelly bar 5 is used for the boss portion 91. The kelly bar 5 and the boss 91, that is, the kelly bar 5 and the rotation transmission device 5 are fixed in a state in which they can move integrally in the axial direction of the kelly bar 5.

  The connecting portion 93 is composed of a pin hole 93b formed through the disk 97, and the box body 99 is fixed on the disk 97 so as to cover the pin hole 93b from above. The connecting portion 93 is provided for detachably connecting the rotation transmitting device 9 to the gripping member 80 of the rotary press-fitting device 7. In this embodiment, the twist lock pin 87 and the connecting portion 93 are mutually connected. These are connected by being related to each other. The connecting portions 93 are provided over the number corresponding to the twist lock pins 87. In the present embodiment, the connecting portions 93 are provided at four locations with a space around the vertical axis of the boss portion 91.

  FIG. 8 is a side view showing a state where the gripping member 80 of the rotary press-fitting device 7 and the rotation transmission device 9 are connected, and FIG. 9 is a cross-sectional view taken along the line BB of FIG. 10 is a view showing a state before and after the twist lock pin 87 on the gripping member 80 of the rotary press-fitting device 7 and the connecting portion 93 of the rotation transmission device 9 are connected, and FIG. 10 (b) is a view of FIG. This corresponds to a cross-sectional view taken along the line CC. 11A is a cross-sectional view taken along the line DD in FIG. 10A, and FIG. 11B is a cross-sectional view taken along the line EE in FIG.

  Before the connection between the gripping member 80 of the rotary press-fitting device 7 and the rotation transmission device 9, as shown in FIGS. 10 (a) and 11 (a), the fixed portion 87a and the movable portion 87b of the twist lock pin 87 are Alignment is performed by rotation of the movable portion 87b so as to have substantially the same shape in plan view. The fixed portion 87a and the movable portion 87b of the aligned twist lock pin 87 are inserted into the pin hole 93b constituting the connecting portion 93 of the rotation transmitting device 9. In addition, the pin hole 93a of the connection part 93 of the rotation transmission device 9 is guided by a tapered surface formed on the upper surface of the movable part 87b of the twist lock pin 87, whereby the connection work can be easily performed.

  In this case, the pin hole 93b of the connecting portion 93 and the fixing portion 87a of the twist lock pin 87 are adjusted in advance to shapes that can be fitted to each other, as shown in FIGS. The gripping member 80 and the rotation transmission device 9 are connected in a state where the relative movement to both sides in the circumferential direction is restricted.

  Thereafter, the movable portion 87b is rotated by the operation of the operation lever 87c of the twist lock pin 87. Accordingly, as shown in FIGS. 10B and 11B, the lower surface of the movable portion 87 b is placed on the upper surface of the member around the pin hole 93 a of the coupling portion 93 of the rotation transmission device 9, that is, the upper surface of the disk 97. The twist lock pin 87 is engaged with the pin hole 93a of the connecting portion 93 and is prevented from coming off. Further, the member around the pin hole 93 b of the connecting portion 93, that is, the disk 97 is sandwiched between the lower surface of the movable portion 87 b of the twist lock pin 87 and the pin base 89. As a result, the gripping member 80 and the rotation transmission device 9 are coupled in a state in which the relative movement in both the circumferential directions is restricted and the relative movement in the vertical direction is further restricted. Will be.

  As described above, when the gripping member 80 and the rotation transmission device 9 are connected in a state in which the relative movement to both sides in the circumferential direction is constrained, the rotational torque from the gripping member 80 is transmitted. When it is connected to the apparatus 9 in a state where the relative movement in the vertical direction is restricted in addition to the restriction of the relative movement in the circumferential direction, the rotation from the gripping member 80 is performed. In addition to the torque, a force due to the vertical movement of the vertical movement cylinder 74, that is, a pushing force is transmitted to the rotation transmission device 9.

  In this state, when the connection between the gripping member 80 and the rotation transmission device 9 is released, the operation lever 87c of the twist lock pin 87 is operated again, and then the rotation transmission device 9 is moved upward to turn the twist lock. The fixed portion 87a and the movable portion 87b of the pin 87 may be removed from the pin hole 93a of the connecting portion 93.

  The mobile crane 3 and the rotary press-fitting device 7 are connected to each other as follows.

  As shown in FIG. 2, the mobile crane 3 has a pair of left and right brackets 45 fixed in two sets at an interval in the left-right direction on the front side of the main frame 31a. As shown in FIGS. 5 and 6, the rotary press-fitting device 7 is provided with a connecting frame 79 so as to extend from the base frame 71 to the rear side. Two are fixed at intervals in the direction.

  As shown in FIG. 2, the bracket 78 of the rotary press-fitting device 7 is disposed between a pair of brackets 45 of the mobile crane 3, and these are fixed pins 47 whose axial direction is substantially parallel to the horizontal direction. Is inserted, and the rotary press-fitting device 7 and the mobile crane 3 are connected by a pin structure using a horizontal pin. An end plate 47 is brought into contact with one end of the fixing pin 47, and these are joined by bolts.

  FIG. 12 is an exploded perspective view in which the connection state between the mobile crane 3 and the rotary press-fitting device 7 is released. The pair of brackets 45 of the mobile crane 3 are formed with pin holes 45a having a shape through which the fixing pins 47 can be inserted, and the bracket 78 on the connection frame 79 side has a long hole 78a having a shape extending in the vertical direction. Is formed.

  As shown in FIG. 13, the rotary press-fitting device 7 is configured to be rotatable about the connecting portion by being connected to the mobile crane 3 with the pin structure as described above. Become.

  For this reason, when excavation work by the kelly bar 5 is not performed, as shown in FIG. 13, the kelly bar 5 is detached from the boom 35 of the mobile crane 3 and one end side of the wire rope 48 is fixed to the fastener 41 of the boom 35. Further, the other end side of the wire rope 48 is fixed to the bracket 74a of the vertical movement cylinder 74 of the rotary press-fitting device 7, and then the boom 35 is lifted to connect the rotary press-fitting device 7 and the mobile crane 3 to each other. It is possible to lift the rotary press-fitting device 7 around the center by rotating it upward. The bracket 74a is fixed to the upper part of each vertical movement cylinder 74, and has an insertion hole through which a wire rope or the like can be inserted.

  Here, since the mobile crane 3 is configured to be capable of self-propelling, the rotary press-fitting device 7 can be transported to the site and removed from the site while maintaining this state. This eliminates the need for a special heavy machine or the like for installing the rotary press-fitting device 7 and improves the working efficiency.

  In particular, since the boom 35 of the mobile crane 3 is configured to be extendable and retractable, when the rotary press-fitting device 7 is transported to the site while maintaining the above-described state, it is like an electric wire laid between a power pole or a steel tower. It becomes difficult for the tip of the boom 35 to be caught with respect to a simple overhead wire, and it becomes possible to more easily carry the rotary press-fitting device 7 to the site by the mobile crane 3.

  In addition, since the bracket 78 on the connection frame 79 side is formed from a long hole 78a extending in the vertical direction, the rotary press-fitting device 7 and the mobile crane 3 can be used in an environment where the ground condition is poor. Even when alignment in the vertical direction is difficult, it can be easily handled.

  Next, an example of a construction procedure for excavating the ground with the rotary excavator 1 as described above to provide a vertical shaft and the operation and effect of the present invention will be described.

  The construction procedure follows the earth drill method. First, the gripping member 80 of the rotary press-fitting device 7 is rotated or swung, and the vertical casing 74 is moved up and down while moving the cylindrical casing 11 in the ground. Press fit to a predetermined depth.

  After that, the kelly bar 5 is inserted into the cylindrical casing 11 while being suspended from the boom 35 of the mobile crane 3, and the rotation transmitting device 9 in which the kelly bar 5 is inserted into the boss portion 91 is inserted into the rotary press-fitting device. 7 to the gripping member 80.

  Here, as will be described later, if necessary, the rotation transmission device 9 can be moved relative to the kelly bar 5 via a connecting means such as a fixing pin 53 so that the rotation transmitting device 9 can be moved integrally in the axial direction of the kelly bar 5. The kelly bar 5 is rotated while appropriately connected, the drill bucket 51 is used to excavate the inside of the cylindrical casing 11 and the ground below it, and a shaft is formed while appropriately discharging the earth and sand stored in the drill bucket 51 to the ground. Let In this case, a stabilizing liquid such as bentonite is appropriately used for the hole wall of the shaft to prevent the hole wall from collapsing.

  After the excavation work by the drill bucket 51 is finished, a reinforcing rod is built in the formed shaft, a tremy pipe is inserted into the shaft, and concrete is poured by pouring ready concrete into the shaft. The cast-in-place pile is provided by pulling out the cylindrical casing, and the work is completed.

  Here, in the rotary excavator 1 according to the present invention, the rotation transmission device 9 is connected to the gripping member 80 of the rotary press-fitting device 7 in addition to the connection portion 93 of the rotation transmission device 9 being connected to the shaft of the kelly bar 5. Rotational torque from the gripping member 80 of the rotary press-fitting device 7 because it is detachably connected to the kelly bar 5 via a connecting means such as a fixing pin 53 so that it can move integrally in the direction. In addition, the pushing force is reliably transmitted to the kelly bar 5 via the rotation transmission device 9.

  For this reason, when excavating a ground such as an intermediate layer having a relatively low N value with the drill bucket 51 of the kelly bar 5, the connection by the fixing pin 53 is removed, and only the rotational torque is transmitted to the kelly bar 5. It is possible to perform excavation work while gradually lowering the drill bucket 51 by its own weight. In this case, it is not necessary to perform the connecting operation with the fixing pin 53 until the depth at which the excavation is impossible due to the dead weight of the kelly bar 5 and the drill bucket 51, so that the operation can be performed quickly.

  Further, when excavating a ground such as a support layer having a relatively high N value by the drill bucket 51 of the kelly bar 5, the kelly bar 5 and the rotation transmission device 9 are connected by the fixing pin 53, and the rotation torque is applied to the kelly bar 5. In addition, it is possible to reliably transmit the pushing force and perform excavation work while lowering the drill bucket 51 by the pushing force of the vertically moving drive means such as the vertically moving cylinder 74 of the rotary press-fitting device 7. In this case, each time the rotary press-fitting device 7 is moved up and down, it is necessary to perform a connecting operation using a fixing pin. Performance will be improved.

  The excavation performance varies depending on the weight of the kelly bar 5 and the like and the performance of the vertical movement cylinder 74. To give specific examples of these numerical values, the combined weight of the kelly bar 5 and the drill bucket 51 is about 1 t. On the other hand, since the compressive force obtained by the vertical movement cylinder 74 per one is about 30 t, the effectiveness of being able to reliably transmit the pushing force by the vertical movement cylinder 74 to the kelly bar 5 is very high. It is considered large.

  Thus, according to the present invention, as needed, only the rotational torque of the rotary press-fitting device 7 can be transmitted to the kelly bar 5 so that excavation work can be performed quickly, and the rotational torque of the rotary press-fitting device 7 and The mode in which the pushing force is reliably transmitted to the Keriba 5 to improve the excavation performance can be excavated using a simple configuration, and the work efficiency is excellent.

  Further, in the present invention, the twist lock pin 87 is used to connect the gripping member 80 and the rotation transmission device 9, so that the relative movement to both sides in the circumferential direction of these connected members is restricted. It is in a state. For this reason, even when the gripping member 80 rotates in either the forward direction or the reverse direction, this rotational torque is reliably transmitted to the rotation transmitting device 9, and thereby, the swinging motion of the gripping member 80. Thus, the rotational torque can be reliably transmitted to the Keriba 5 via the rotation transmission device 9.

  In addition, as a mechanical element for connecting the kelly bar 5 and the rotation transmission device 9 so as to be integrally rotatable, in the above-described embodiment, connection by fitting the boss portion 91 of the kelly bar 5 and the rotation transmission device 9 is given. However, in this case, the cross-sectional shape of the boss portion 91 and the kelly bar 5 is not limited to a square cross section, and may be formed in a polygonal cross-sectional prism shape, or the fitting hole 91a of the boss portion 91 or the kelly bar 5 Splines may be formed on the outer periphery. Further, a key groove may be provided on the inner surface of the fitting hole 91a of the boss portion 91 and the outer surface of the kelly bar 5, and the key may be inserted into these so as to be integrally rotatable.

  Further, the configuration for connecting the gripping member 80 of the rotary press-fitting device 7 and the connecting portion 93 of the rotation transmission device 9 is not limited to the twist lock pin 87 as in the present embodiment, and at least the gripping member 80 is used. It is only necessary that the rotation and the vertical movement can be coupled so as to be transmitted to the rotation transmission device 9. For this reason, for example, an L-shaped groove is provided in the gripping member 80 of the rotary press-fitting device 7, and a bar that can be fitted in the L-shaped groove is provided as the connecting portion 93 of the rotation transmission device 9. You may make it implement | achieve by making the connection part 93 of the rotation transmission device 9 which consists of a rod enter in the front end side of a shape-like groove | channel.

  In addition, the gripping member 80 is particularly configured as in the present embodiment as long as the gripping member 80 is configured to be rotatable in a state where the cylindrical casing 11 is gripped from the outer peripheral side in the known rotation transmission device 7. It is not limited to.

  Moreover, the connection part 93 which comprises the rotation transmission apparatus 9 should just be provided at least 2 around the vertical axis | shaft of the boss | hub part 91, and the aspect of arrangement | positioning with respect to the boss | hub part 91 is not specifically limited. Further, the reinforcing plate 95, the circular plate 97, and the box body 99 constituting the rotation transmission device 9 are not essential components, and can transmit rotational torque between the boss portion 91 and the connection portion 93 of the rotation transmission device 9. As long as it is provided, the shape, position, etc. are not particularly limited.

It is a side view which shows the whole structure of a resisting excavator, (a) is a figure which shows the state before inserting a kelly bar in a cylindrical casing, (b) is inserting a kelly bar in a cylindrical casing. FIG. It is a schematic plan view which shows the structure of the lower traveling body of a mobile crane. It is a side view which shows the structure of a kelly bar and a rotation transmission apparatus. FIG. 4 is a sectional view taken along line AA in FIG. 3. It is a side view which shows the structure of a rotary press-fitting apparatus. It is a top view which shows the structure of a rotary press-fit apparatus. It is a side view for demonstrating operation | movement by the up-and-down moving cylinder of a rotary press-fit apparatus. It is a side view which shows the state which connected the holding member and rotation transmission apparatus of the rotary press-fit apparatus. It is the BB sectional drawing of FIG. It is a figure which shows the state before and behind which connects a twist lock pin and the connection part of a rotation transmission apparatus. (A) is the DD sectional view taken on the line of Fig.10 (a), (b) is the EE sectional view taken on the line of FIG.10 (b). It is a schematic perspective view which shows the state of the connection part of a mobile crane and a rotary press-fitting apparatus. It is a side view for demonstrating the effect by connecting a mobile crane and a rotary press-fit apparatus with a pin structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shaft excavator 3 Mobile crane 5 Kelly bar 7 Rotation press-fitting device 9 Rotation transmission device 11 Cylindrical casing 31 Lower traveling body 31a Main frame 31b Side frame 31c Caterpillar 33 Upper turning body 35 Boom 35a Sheave 37 Wire rope 39 Winch 41 Fastening 43 Sheave block 45 Bracket 45a Pin hole 47 Fixing pin 48 Wire rope 49 End plate 51 Drill bucket 53 Fixing pin 55 Pin hole 71 Base frame 72 Leg 73 Lifting frame 74 Vertical motion cylinder 74a Bracket 75 Rotating frame 76 Rotating motor 77 Opening 78 Bracket 78a Long hole 79 Connecting frame 80 Holding member 81 Fixed segment 83 Moving segment 85 Opening and closing cylinder 87 Twist lock pin 87a Fixed portion 87b Movable portion 87c Work lever 89 pin seat 91 boss 91a fitting hole 91b pin hole 93 connecting portion 93a pin holes 95 reinforcement plate 97 side plate 99 box body

Claims (5)

A crane with a boom,
A kelly bar that is inserted in a state suspended from the boom into a cylindrical casing embedded in the ground, and a drill bucket is attached to the lower end portion;
A gripping member that is arranged along a circumferential direction around the axis of the Kellyba and configured to be rotatable in a state where the cylindrical casing is gripped from the outer peripheral side; and a vertical movement drive means that moves the gripping member up and down A rotary press-fitting device having
A boss portion through which the kelly bar is slidably inserted in the axial direction; a plurality of boss portions provided around the axis of the boss portion; and a connecting portion detachably connected to the gripping member from above; A rotation transmission device configured to be integrally rotatable;
A shaft excavator comprising: fixing means capable of fixing a slide of the kelly bar in the axial direction with respect to the rotation transmission device. The boss portion of the rotation transmission device is composed of a cylindrical body,
The shaft excavator according to claim 1, wherein the fixing means includes a fixing pin that penetrates the cylindrical body and the kelly bar. The rotary press-fitting device further includes a twist lock pin provided with a movable portion that protrudes from the upper portion of the gripping member and is rotatable around the protruding direction at the upper end.
The rotation transmission device is connected to the gripping member by rotating a movable portion of the twist lock pin inserted in a pin hole formed in the connection portion. The shaft excavator according to 2. The crane is configured to be self-propelled,
The rotary press-fitting device is configured to be rotatable about the connecting portion by being connected to the crane with a pin structure using a horizontal pin. The shaft excavator according to claim 1. The shaft excavator according to claim 4, wherein the boom of the crane is configured to be extendable and contractible in an axial direction thereof.

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