JP5479943B2 - Hammer grab - Google Patents

Description

  The present invention relates to a hammer grab for excavating a hole for placing a pile or pipe in the ground.

  In foundation pile construction work at a construction site, excavation work is performed using an excavator that combines a gantry and a swivel boring machine. Specifically, the boring machine is turned and pushed into the ground while rotating the casing tube, and the earth and sand in the casing is excavated by a hammer grab suspended from a gantry. This excavation is performed by lowering the hammer grab suspended from the gantry into the casing tube and then dropping the winch from a certain height. Due to this fall, the shell opened at the tip of the hammer grab pierces into the ground, and when the winch is rolled up from this state, the shell closes and is pulled up with earth and sand inside.

  The hammer grab is composed of a cylindrical frame formed in accordance with the inner diameter of the casing tube and a pair of shells attached to the lower end of the frame so as to be opened and closed. The shell is connected to an arm, and an open / close operation is performed by moving the arm up and down with a wire extending from the upper end of the frame. As the open / close drive mechanism of the shell, a braking portion comprising a plurality of pulleys is provided in the frame, and a wire is connected to the arm via the brake portion, thereby facilitating the opening / closing operation of the shell. The force at the time of digging up and holding excavated material such as earth and sand is reduced (Patent Document 1).

  Further, as the opening / closing drive mechanism, there is a hammer grab in which a cylinder is provided on an arm connected to a shell without using a pulley, and the shell can be opened / closed by expansion / contraction of the cylinder (Patent Document 2). ).

JP 2004-76301 A JP-A-9-158658

  In the hammer grab having a drive mechanism with a plurality of pulleys as disclosed in Patent Document 1, the opening and closing operation of the shell can be made smooth, but the pulley is arranged inside the frame body. Since a space has to be provided, there is a problem that the entire length of the frame body is increased. Therefore, during excavation work, it is difficult to hang from the gantry or secure a sufficient fall space for the shell to pierce the ground when the work space in the sky is narrow or limited Was not easy. Further, since the wires are passed through the plurality of pulleys, assembly and adjustment are not easy, and the wires may be disconnected during excavation work.

  On the other hand, the hammer grab having a cylinder opening / closing drive mechanism disclosed in Patent Document 2 does not require a mechanical part such as a pulley, so that the inside of the frame body can be simplified. In addition, since a hydraulic device, a power supply device, and the like are required for operating the cylinder, there is a problem in that the external device configuration is increased and the cost for driving is increased.

  Accordingly, an object of the present invention is to facilitate excavation work in a low altitude by shortening the overall length of the frame by arranging a part of the opening / closing mechanism for opening and closing the shell to the outside of the frame, and shortening the overall length. By providing a weight member on the side surface of the frame, a hammer grab that can increase the excavation force is provided.

In order to solve the above problems, a hammer grab according to the present invention is arranged at least a pair of shells having a digging blade at a tip, a cylindrical frame to which the shell is attached so as to be openable and closable, and an inside of the frame. A pulley section spanned between the shell and the frame, a lifting plate that moves up and down in the frame by the pulley portion, and one end fixed to the lifting plate and the other end fixed to the frame. And a plurality of spring members for biasing the shell in an open state, and weight members provided along the outer side surface of the frame and projecting from the outer side surface.

  According to the hammer grab of the present invention, a pulley portion that opens and closes the shell is provided inside the frame to which the shell can be opened and closed, and a spring member that biases the shell in an open state is provided outside the frame. Since it is provided and configured, the internal configuration of the frame can be simplified and the overall length of the frame can be shortened. Further, by attaching a plurality of weight members so as to protrude from the outer surface of the frame, a constant weight can be added to the frame whose overall length is shortened. As a result, the hammer grab can be suspended and disposed in a place where the work space in the sky is narrow, and the excavation ability can be enhanced.

  In addition, by providing a plurality of openings on the side surface of the frame, it is possible to easily drain water when the earth and sand are scraped out by the shell.

It is sectional drawing at the time of the excavation attitude | position of the hammer grab which concerns on this invention. It is sectional drawing at the time of the obstruction | occlusion attitude | position of the said hammer grab. It is a side view of the released state of the hammer grab. It is a side view of the closed state of the hammer grab. It is a top view of the said hammer grab. 1 is an overall configuration diagram of a low-headed excavator equipped with a hammer grab. It is a front view of the excavator. It is a front view when suspending and supporting a hammer grab. It is explanatory drawing which shows the conveyance and excavation method of a hammer grab.

  Hereinafter, embodiments of a hammer grab according to the present invention will be described in detail with reference to the accompanying drawings. 1 to 4 show the internal structure of the hammer grab 50. The hammer grab 50 is used for deep hole excavation and root cutting of a building foundation, and includes a frame 51 and a pair of shells 52 that can be opened and closed with the lower end of the frame 51 as a rotation fulcrum. Yes.

  As shown in FIG. 1, the frame 51 has a circular opening surface 55 that fits the inner diameter of a casing tube 33 that is previously placed at an excavation site, and an internal space 59 that extends above the opening surface 55. A cylindrical body portion 57 having a cylindrical shape and a disk-shaped top plate portion 56 disposed at the upper end portion of the body portion 57 are configured. A pair of shells 52 are attached to the lower end of the body portion 57 via a hinge 58 so as to be able to rotate. In addition, a disc-shaped lifting plate 60 that is slidable in the vertical direction along the inner peripheral surface of the body portion 57 is disposed in the internal space 59. In the normal state, the lifting plate 60 is urged and arranged by the spring member 62 so as to be substantially the same height as the lower end surface of the body portion 57.

  The body portion 57 is formed of a heavy steel material, and a weight member 63 for further adding weight is provided along the outer surface. As shown in FIGS. 3 to 5, the weight member 63 is formed of a vertically long plate-like body that radially projects the outer surface of the body portion 57 along the longitudinal direction. The weight member 63 is made of the same steel material as that of the body portion 57, and is arranged at a plurality of equal intervals with good balance along the outer surface of the body portion 57.

  In addition, the weight member 63 can be adapted to the inner diameter of the casing 33 by projecting radially from the outer surface of the body portion 57 with a constant width, so that the weight member 63 does not tilt when inserted into the casing 33. It has a role as a guide member that guides to. Thus, in order to guide the hammer grab 50 through the casing 33 in a well-balanced manner, the weight members 63 are preferably arranged on the outer periphery of the body portion 57 at equal intervals with the same shape and weight.

  In addition, a plurality of openings 65 are formed on the surface of the body portion 57 where the weight plate 63 is not provided in order to discharge moisture contained in the earth and sand scooped up by the shell 52 to the outside. The opening 65 is formed by punching the side surface of the body portion 57 formed in a cylindrical shape into a vertically long shape. Moreover, the trunk | drum 57 which has the said opening part 65 can also be formed by forming a vertically long steel material panel combining a cylindrical shape with a predetermined gap.

  Each shell 52 includes a drilling blade 64 having a spoon-like scooping recess 68 that pierces the drilled material (ground) in the casing tube 33, and a link portion 67 that connects one end of the drilling blade 64 and the hinge 58. Is provided.

  Arms 69 extend from the lower surface of the lift plate 60 toward the pair of shells 52, and the lower ends of the arms 69 and the link portion 67 are connected. The arm 69 has a fixed length, and as shown in FIG. 1, when the wire 30 a is not pulled up, the elevating plate 60 is urged to the lower end side of the frame 51 by the spring member 62, The front end surface of the shell 52 is pushed down so that each excavation blade 64 opens. As shown in FIG. 2, when the elevating plate 60 slides upward in the internal space 59 against the spring member 62, The shell 52 is closed. The range of the opening / closing operation of the shell 52 is restricted by the vertical width of the internal space 59 of the frame 51.

  In the internal space 59 of the frame 51, a pulley portion for moving the elevating plate 60 up and down is provided. The pulley section is attached to the lower vicinity of the top plate section 56, the fixed pulley section 75 is attached to the upper surface of the lift plate 60, and the movable pulley section 76 moves up and down together with the lift plate 60, and the fixed pulley section 75. And a wire 30a bridged between the movable pulley unit 76 and the movable pulley unit 76.

  The fixed pulley portion 75 includes an upper rotary shaft 77 that is attached and fixed above the internal space 59 of the frame 51, and one upper pulley 78 that is rotatably supported at a substantially central portion of the upper rotary shaft 77. The movable pulley portion 76 is in contact with the inner peripheral surface of the frame 51 and surrounds a circular guide wall 79 surrounding the outer peripheral portion of the elevating plate 60, and a lower rotary shaft 80 attached to the inside of the guide wall 79, Two lower pulleys 81a and 81b that are rotatably supported at a substantially central portion of the lower rotating shaft 80 are provided. The upper pulley 78 and the lower pulleys 81a and 81b have substantially the same shape and diameter.

  The wire 30 a is inserted into the internal space 59 of the frame 51 through the suspension support portion 70. The wire 30a is lowered straight down in the internal space 59, first hung on one lower pulley 81a, and then folded upward and hung on the upper pulley 78. Then, the tip end portion of the wire 30a hung on the upper pulley 78 is folded down as it is and hung on the other lower pulley 81b, and then fixed to the lower surface of the top plate portion 56.

  The spring member 62 is disposed at two positions facing the outside of the frame 51. The spring member 62 is formed by a coil spring, and has one end fixed to the outer peripheral surface of the top plate portion 56 and the other end biasing the hinge 58 of each shell 52 attached to the lower end portion of the frame 51 downward. To be fixed.

  As shown in FIGS. 1 and 3, in a state where the wire 30a is not pulled by the winch, the shell 52 is opened by the elastic force of the spring member 62. However, as shown in FIGS. As described above, when the wire 30a is pulled, the two lower pulleys 81a and 81b are drawn toward the upper pulley 78 while rotating. As a result, the elevating plate 60 gradually rises against the bias of the spring member 62. In this way, by pulling the wire 30a over the upper pulley 78 and the lower pulleys 81a and 81b, the opening / closing speed of the shell 52 can be adjusted, and the excavated earth and sand can be reliably grasped.

  In the hammer grab 50 of the present embodiment, a pair of spring members 62 are disposed outside the frame 51, and the internal space 59 has enough space for the fixed pulley portion 75 and the movable pulley portion 76. Good. For this reason, the entire length of the entire frame 51 including the shell 52 can be suppressed to approximately 2 m or less. The minimum vertical space of the internal space 59 is defined by the open / close width of each shell 52, and is a separation distance that allows the upper pulley 78 and the lower pulleys 81a and 81b to be close to each other without contact. Thus, by shortening the overall length of the hammer grab 50, it can be sufficiently installed even in a low work space described later.

  Further, by providing the weight member 63 projecting from the outer side surface of the body portion 57, it is possible to cover the shortage of the entire weight of the hammer grab 50 due to the shortening of the overall length of the frame 51 and to enhance the excavation ability. Further, since a plurality of vertically long openings 65 are formed in the body portion 57, unnecessary moisture can be discharged to the outside when the hammer grab 50 is pulled up from the casing 33. As a result, disposal work such as excavated earth and sand can be performed efficiently.

  Next, based on FIG.6 and FIG.8, the Example in the case of excavating in the low sky using the said hammer grab 50 is described. The hammer grab 50 is provided with a suspension support 70 at the center of the top surface of the top plate portion 56. As shown in FIGS. 6 and 8, the suspension support portion 70 is attached to a suspension fixing portion 71 suspended from the horizontal base 14 of the excavator 10 via a wire 30 b, and the entire frame 51 is predetermined. An insertion hole 72 for inserting the wire 30a into the frame 51 is formed from the upper surface to the lower surface. In addition, a plurality of engagement protrusions 73 are provided on the outer peripheral portion for mounting on the suspension fixing portion 71. One suspension fixing portion 71 is formed in a ring shape having a hole 74 for inserting the suspension support portion 70 in the center portion, and is engaged with the engagement protrusion 73 on the inner side surface. An engaging groove (not shown) is provided.

  When the suspension fixing portion 71 is mounted, the entire frame 51 is lifted by winding the wire 30a connected to the lifting plate 60 with the winch 37 shown in FIG. The engagement protrusion 73 is attached to the suspension fixing portion 71 by inserting the suspension support portion 70 into the hole 74 of the suspension fixing portion 71 waiting upward. In this state, the hammer grab 50 can be moved to a predetermined excavation place by the wire 30b that suspends and fixes the suspension fixing portion 71. When the excavation site is moved and excavated, the wire 30 a directly connected to the lifting plate 60 is wound up so that the engagement protrusion 73 is detached from the suspension fixing portion 71, and the wire 30 a is removed from the winch 37. By opening, the shell 52 is held in the excavation posture by the biasing force of the spring member 62. And it is made to fall as it stabs into the ground exposed in the casing tube 33 in the state hold | maintained in this excavation attitude | position.

  Next, an embodiment of a low-headed excavator using the hammer grab 50 will be described. As shown in FIG. 6, the excavator 10 includes a horizontal frame 14 installed via a frame 13 on an excavation base 12 provided in a movable base machine 11, and a rail 15 provided on the horizontal frame 14. The carriage 16 is movably disposed along the carriage 16 and the hammer grab 50 is supported by the carriage 16 so as to be lifted and lowered. The rail 15 is composed of a fixed rail 18 fixed to the frame 13 and a movable rail 19 disposed so as to protrude from the fixed rail. Since the excavator 10 can be used in a building such as a warehouse or a garage where the work space in the sky is limited or in a tunnel, the horizontal platform 14 mounted on the base machine 11 is used. The height H from the ground surface is set within a maximum of 5 m.

  The base machine 11 is a heavy machinery vehicle for construction work, an excavation base 12 on which the frame 13 is placed, an actuator 21 for moving and raising / lowering the carriage 16 and the hammer grab 50, and the actuator 21 And a drive source 22 for driving the motor. A tubing portion 34 for pushing in a casing tube 33 described later is installed in advance at the excavation place, and the base machine 11 is moved so that the excavation base portion 12 is placed directly above the tubing portion 34.

  The frame 13 is disposed on the excavation pedestal 12, and is erected on the four main support legs 23 that horizontally support the fixed rail 18 and on the operation unit 11 a side of the base machine 11. The actuator 21 has a pair of left and right rear support legs 24a to which one end of the actuator 21 is fixed. In addition, a pair of left and right front support legs 24b that support the distal end F side of the movable rail 19 are provided as necessary. The front support leg 24b is supported so as to follow the slide of the movable rail 19 in the horizontal direction.

  As shown in FIG. 7, the fixed rails 18 are arranged in a pair of left and right parallels on the frame 13, and movable rails 19 are slidably supported by the fixed rails 18. Further, guide grooves 20 for mounting the carriage 16 so as to be movable in the horizontal direction are formed on the opposing inner side surfaces of the pair of movable rails 19, respectively.

  The pulley section 26 includes a first pulley 26a at the center and a pair of second pulleys 26b on the left and right sides of the first pulley 26a. As shown in FIG. 7, a wire 30a for operating an opening / closing mechanism provided in the hammer grab 50 is hung on the first pulley 26a. In addition, a pair of wires 30b for hanging a suspension fixing portion 71 that can be attached to and detached from the suspension support portion 70 provided on the hammer grab 50 is hung on the second pulley 26b.

  As shown in FIG. 8, a hammer grab 50 is directly suspended from the first pulley 26a. The wires 30a and 30b hung on the first pulley 26a and the second pulley 26b are driven up and down via winches 37 provided in the base machine 11, respectively. As shown in FIG. 1, the wire 30 a is connected to the lifting plate 60 through the upper frames 54 and 84. Then, when the wire 30a spanned between the fixed pulley portion and the movable pulley portion in the frame 51 is driven up by a winch 37, the elevating plate 60 moves upward against the spring member 62. Accordingly, each arm 69 is pulled up, and one end of each shell 52 connected to the link portion 67 is lifted. The hammer grab 50 is lifted above the excavation work position by the wire 30b in a state where the suspension support part 70 is attached to the suspension fixing part 71, and is separated from the suspension support part 70 at a predetermined height position. To drop. The shell 52 is in an open state when dropped, and is pierced into the ground as it is. In this state, the wire 30a is wound up by the winch 37, so that the shell 52 is closed while holding an excavated material such as soil or rock, and the wire body 30a is further lifted to support the frame main bodies 51 and 81 in a suspended state. It is attached to the suspension fixing part 71 via the part 70. At this time, excavation work can be performed while discharging unnecessary moisture contained in the earth and sand from the opening provided in the frame 51 to the outside.

  As shown in FIG. 9, the hammer grab 50 suspended from the pulley portion 26 via the suspension fixing portion 71 is positioned and fixed by the carriage 16 directly above the casing tube 33 driven by the tubing portion 34. To do. Then, the hammer grab 50 is separated from the suspension fixing portion 71 from this position, dropped into the casing tube 33, and the tip of the excavation blade 64 of the open shell 52 is driven into the ground. Thereafter, the winch 37 is wound up to close the shell 52 and dig up the ground. After the excavation work, the hammer grab 50 is pulled up from the casing tube 33, and the carriage 16 is advanced along the movable rail 19 in a state where the hammer grab 50 is attached to the suspension fixing portion 71. It moves to the vicinity of the tip F of the movable rail 19 that is separated. At this position, by opening the shell 52, the excavated material such as excavated soil and rock can be discharged. In this way, the hammer grab 50 is reciprocated in the horizontal direction by the carriage 16 from the position above the casing tube 33 to the place where the earth is discharged, thereby excavating and discharging the earth in a place where the space is limited. Can be performed easily and efficiently.

  As described above, by using the hammer grab 50 of the present invention, the excavation apparatus 10 that is lowered so that the maximum height of the horizontal gantry 14 is within about 5 m can be excavated in the low sky. It was.

  In addition, although the hammer grab 50 of the said embodiment was comprised by a pair of shell 52, it can also be comprised by three or more shells. In the case of being constituted by a plurality of shells as described above, an efficient excavation work even in a low altitude can be achieved by improving the spring member 62 having an urging force corresponding to the number of shells outside the frame 51. It can be performed.

DESCRIPTION OF SYMBOLS 10 Excavator 11 Base machine 11a Operation part 12 Excavation base seat part 13 Frame 14 Horizontal stand 15 Rail 16 Carriage 18 Fixed rail 19 Movable rail 20 Guide groove 21 Actuator 22 Drive source 23 Main support leg 24a Back support leg 24b Front support leg 26 Pulley Part 26a First pulley 26b Second pulley 30a, 30b Wire 33 Casing tube 34 Tubing part 37 Winch 50 Hammer grab 51 Frame 52 Shell 55 Opening surface 56 Top plate part 57 Body part 58 Hinge 59 Internal space 60 Lift plate 62 Spring Member 63 Weight member 64 Excavation blade 65 Opening portion 67 Link portion 68 Scooping recess 69 Arm 70 Suspension support portion 71 Suspension fixing portion 72 Insertion hole 73 Engagement protrusion 74 Hole portion 75 Constant pulley portion 76 Dynamic pulley portion 7 Upper rotary shaft 78 on the pulley 79 guide wall 80 below the rotating shaft 81a, 81b under the pulley

Claims (6)

At least a pair of shells having a drilling blade at the tip;
A cylindrical frame to which the shell can be opened and closed downward;
A pulley part arranged inside the frame and spanned between the shell and the frame;
A lifting plate that moves up and down in the frame by the pulley;
A spring member for biasing state is located outside one end opened the shell is fixed to the other end frame to the lifting plate of the frame,
A hammer grab comprising a plurality of weight members provided along an outer side surface of the frame and projecting from the outer side surface.   The pulley unit includes a fixed pulley unit arranged above the frame, a moving pulley unit connected to the fixed pulley unit via a wire, and the frame integrally formed with the moving pulley unit. The hammer grab according to claim 1, further comprising an elevating plate disposed so as to be movable up and down, wherein one end of each shell is coupled to the elevating plate via a coupling member.   The hammer grab according to claim 1, wherein the cylindrical frame is provided with a plurality of openings on a side surface.   The hammer grab according to claim 1, wherein the spring member is provided as a pair opposed to the outer surface of the frame.   The hammer grab according to claim 1, wherein the weight members are provided at equal intervals along the outer surface of the frame, and each of the weight members is formed of a vertically long plate-like body.   The hammer grab according to claim 1, wherein the weight member is provided radially on an outer surface of the frame.

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