JP2015121022A - Grab bucket and capacity changing method of grab bucket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grab bucket capable of changing capacity while improving working efficiency and safety without increasing a suspension load.SOLUTION: A grab bucket includes an upper frame 1, a lower frame 2, a shell 4, a rod 5, a shell cover 6, and switching means for switching the shell cover 6 between a normal position and a capacity reduction position. The switching means includes a hinge 11 for turning the shell cover 6 to the shell 4, normal position fixing mechanisms 12, 13 and 16 for fixing the shell cover 6 in the normal position, and capacity reduction position fixing mechanisms 14, 15, 16 and 17 for fixing the shell cover 6 in the capacity reduction position. The normal position fixation is released in the state that the shell cover 6 is suspended and supported, and the shell cover 6 is turned around the hinge 11, and the shell cover 6 is fixed in the capacity reduction position.

Description

  The present invention relates to a grab bucket used for dredging and excavating mud and sediment deposited on the seabed and the like, and more particularly to a sealed grab bucket.

  The grab bucket includes an upper frame, a lower frame, a pair of left and right shells that are pivotally supported by the lower frame, and a rod that connects the upper frame and the shell. Suspend a grab bucket from a dredger or other crane. Drop an open shell onto the seabed or the water. When the shell is closed, it is crushed by the edge portions of the left and right shells, and the shell is pulled up in the closed state. The shell is opened again on the earth and sand carrier, and mud and earth and sand are loaded onto the earth and sand carrier.

  At this time, if the upper part of the shell is open, sludge and sewage leak from the upper part of the shell, causing turbid water. Accordingly, a sealed grab bucket is often used from the viewpoint of protecting the water environment.

  By the way, the larger the volume of the grab bucket, the more mud and earth and sand that can be dredged at a time. Therefore, in general, when the volume of the grab bucket is large, efficient work is possible. On the other hand, it is difficult to finish the bottom of the water flat, and thin layer excavation is performed when finishing. That is, the amount of earth and sand per grab is reduced.

  As a result of the decrease in the amount of earth and sand, the amount of remaining water in the bucket increases, and the mud content (ratio of the amount of earth and sand to be dredged with respect to the bucket volume) decreases. Excess moisture reduces the efficiency of earth and sand transport, such as increasing the number of times that the ship is transported. Furthermore, the amount of processing at the earth and sand treatment plant increases, and the processing efficiency decreases.

  On the other hand, it is conceivable to replace the grab bucket with a small volume during thin layer excavation. However, it is not preferable to prepare and replace a plurality of grab buckets having different volumes from the viewpoint of space constraints on the dredger and the work burden of replacement. The replacement work may take all day.

  In order to solve the above problem, a variable volume grab bucket has been proposed. The grab bucket described in Patent Document 1 is reduced in volume by a partition plate installed in the shell. The grab bucket described in Patent Document 2 is reduced in volume by a block installed in the shell.

JP 2013-57186 A JP 2013-57186 A

  However, the grab buckets described in Patent Documents 1 and 2 have the following problems.

  Although there is no description about the material of a partition plate or a block, it is presumed that it is probably made of iron. Since these are attached separately to the grab bucket, the total suspended load increases and the load on the dredger crane increases. That is, there is a problem related to the suspended load.

  Moreover, a partition plate and a block are provided inside the shell. For this reason, the worker opens the shell in conjunction with the crane operation of the dredger and the worker works in the shell. A sufficient working space cannot be secured in the shell, and there is a problem relating to workability. For example, it may take half a day to install partition plates and blocks inside the shell. Compared with the work of replacing the grab bucket itself, the workability is improved, but further workability improvement is required.

  Furthermore, the work of lifting a heavy object (partition plate or block) to the overhead of the worker in the shell requires safety considerations. That is, there is a problem related to safety.

  This invention solves the said subject, and it aims at providing the grab bucket which can change a volume, improving workability | operativity and safety | security without increasing a hanging load.

  One aspect of the present invention that solves the above problems includes an upper frame, a lower frame, a shell that is pivotally supported by the lower frame, a rod that connects the upper frame and the shell, and an upper side of the shell. A grab bucket including a shell cover to be sealed and switching means for switching the shell cover between a normal position and a volume reducing position.

  By switching the position of the shell cover, the volume can be changed while improving workability and safety without increasing the suspension load.

  Preferably, in the above invention, the switching means includes a rotation mechanism that rotates the shell cover with respect to the shell, a normal position fixing mechanism that fixes the shell cover in a normal position, and a volume reduction position of the shell cover. And a volume reduction position fixing mechanism for fixing to the volume.

  By rotating, it is possible to switch between the normal position and the volume reducing position.

  More preferably, in the above-mentioned invention, a top plate connected to the top of the main body of the shell is further provided, and the normal position fixing mechanism engages the shell cover and the top plate.

  Thereby, the sealing property in a normal position is ensured. Furthermore, the normal position fixing mechanism can suspend and support the shell cover.

  Preferably, in the above invention, the volume reduction position fixing mechanism fixes the shell cover at a position where end surfaces of the pair of left and right shell covers face each other.

  Thereby, the volume can be minimized without the shell covers interfering with each other. In addition, sealing at the volume reduction position is ensured.

  Preferably, in the above invention, the volume reduction position fixing mechanism includes an engagement pin that penetrates an engagement hole provided in a wall surface of the shell and an engagement hole provided in the shell cover.

  As a result, work is performed from outside the shell, and workability and safety are improved.

  Preferably, in the above invention, the shell cover has a hanging jig on the outer surface.

  As a result, work is performed from outside the shell, and workability and safety are improved.

  Preferably, in the above invention, the shell cover has a sealing material on a peripheral edge of the outer surface.

  Thereby, sealing property is ensured.

  One aspect of the present invention that solves the above problems includes an upper frame, a lower frame, a pair of left and right shells, a rod, a shell cover that seals the upper side of the shell, and one side of the shell cover as a rotation axis. A grab bucket volume changing method comprising: switching means for switching the shell cover between a normal position and a volume reducing position; and a hanging jig provided on an outer surface of the shell cover, wherein the upper frame, the lower frame, the rod In any case, the shell cover is suspended and supported via the suspension jig, and the shell cover is pivoted with the shell cover suspended and switched to the normal position and the volume reduction position.

  Preferably, in the above invention, an engagement pin is passed through an engagement hole provided in a wall surface of the shell and an engagement hole provided in the shell cover, and the shell cover is fixed at a volume reduction position.

  According to the grab bucket of the present invention, the volume can be easily changed. Furthermore, workability and safety can be improved without increasing the suspended load.

Grab bucket schematic configuration diagram (normal position) (first embodiment) Grab bucket schematic configuration diagram (volume reduction position) (first embodiment) Grab bucket schematic perspective view (normal position) (first embodiment) Grab bucket schematic perspective view (volume reduction position) (first embodiment) Switching operation explanatory diagram (first embodiment) Grab bucket schematic configuration diagram (normal position) (second embodiment) Grab bucket schematic configuration diagram (normal position) (third embodiment)

<First Embodiment>
~Constitution~
The present invention is a sealed grab bucket. Sealing in the grab bucket means a degree to prevent sludge and sewage from leaking and causing turbid water. 1 and 2 show a schematic configuration of the grab bucket. Although it is a front view, for convenience of explanation, the vicinity of the shell cover is shown as a cross-sectional view. FIG. 3 is a schematic perspective view corresponding to FIG. FIG. 4 is a schematic perspective view corresponding to FIG.

  The basic configuration of this embodiment will be described. The grab bucket includes an upper frame 1, a lower frame 2, a shell 4, and a rod 5.

  The upper frame 1 is connected to the suspension wire at the upper part. The lower frame 2 is moved up and down with respect to the upper frame 1 by an opening / closing wire.

  The shell 4 is a pair of left and right. In addition, although the rod 5 and the shell cover 6 etc. are a pair of left and right corresponding to the shell 4, the pair of left and right is appropriately omitted below.

  An upper end portion of the shell 4 is rotatably supported by a rotation shaft 3 a provided on the lower frame 2.

  The shell 4 is composed of two opposing side plates 41, a bottom plate 42, and two opposing extending plates 43. The side plate 41 has a substantially fan shape, and the central angle of the fan is 45 to 75 degrees. A bottom plate 42 is continuously provided along the arc of the fans of the two side plates 41. On the outer edge of the side plate 41, an extending plate 43 for providing the rotating shaft 3a and the rotating shaft 3c is extended.

  The rod 5 connects the upper frame 1 and the shell 4. In other words, the upper frame 1 is provided with a rotating shaft 3b, and one end of the rod 5 is rotatably supported via the rotating shaft 3b. A rotating shaft 3c is provided on the outer edge of the shell 4, and the shell 4 is rotatably supported on the other end of the rod 5 via the rotating shaft 3c.

  With the above configuration, when the lower frame 2 is moved downward by the open / close wire, the support shaft 3a is moved downward, and the pair of left and right shells 4 are pivoted away from each other about the support shaft 3a, so that the shell 4 is opened. It becomes a state. Further, when the lower frame 2 is moved upward by the opening / closing wire, the support shaft 3a is moved upward, and the pair of left and right shells 4 are rotated in a direction approaching each other about the support shaft 3a, so that the shell 4 is in a closed state. Become.

  A characteristic configuration of the present embodiment will be described.

  A shell cover 6 is provided on the upper side of the shell 4. The shell cover 6 may have a shape corresponding to the opening formed by the end face of the side plate 41 and the end face of the bottom plate 42, but shows a rectangular shape as an example. A hinge 11 is provided at one end of the shell cover 6, and the shell cover 6 is connected to the shell 4 via the hinge 11 so as to be rotatable. An imaginary line connecting the vicinity of the outer ends of the arcs of the two opposing side plates 41 (where the shells are in contact with each other) is used as the rotation axis of the hinge 11. The hinge 11 constitutes a turning mechanism for turning the shell cover 6 with respect to the outer edge portion of the shell 4.

  A top plate 21 is connected to the top of the shell 4 main body. In other words, the top plate 21 is disposed so as to span the two side plates 41.

  The shell cover 6, the top plate 21, the side plate 41 and the bottom plate 42 form a sealed space in the shell closed state.

  A fixing jig having pin holes 12 is extended on the outer surface of the top plate 21. On the other hand, a fixing jig having a pin hole 13 is extended on the outer surface of the shell cover 6. Further, the pin hole 12 and the pin hole 13 are configured to coincide with each other in a state where the other end portion of the outer surface of the shell cover 6 (the side opposite to the side where the hinge is provided) and the inner surface of the top plate 21 are engaged. ing. Then, when the pin 16 penetrates the pin hole 12 and the pin hole 13, the shell cover 6 is fixed at the normal position. The pin hole 12, the pin hole 13, and the pin 16 constitute a normal position fixing mechanism that fixes the shell cover 6 to a normal position.

  The side plate 41 is provided with pin holes 14, while a fixing jig having pin holes 15 is extended on the inner surface of the shell cover 6. Further, a fixed position engaging plate 17 is provided inside the side plate 41, and the fixed position engaging plate 17 and the other end of the inner surface of the shell cover 6 are engaged with each other so that the end surfaces of the pair of left and right shell covers 6 face each other. Is configured to do. Further, the pin hole 14 and the pin hole 15 are configured to coincide with each other with the end surfaces of the pair of left and right shell covers 6 facing each other. Then, when the pin 16 penetrates the pin hole 14 and the pin hole 15, the shell cover 6 is fixed at the volume reducing position. The pin hole 14, the pin hole 15, the pin 16, and the fixed position engagement plate 17 constitute a volume reduction position fixing mechanism that fixes the shell cover 6 to the volume reduction position.

  The shell cover 6 is switched between the normal position and the volume reduction position by the rotation through the hinge 11.

  The rotation mechanism 11, the normal position fixing mechanisms 12, 13, 16 and the volume reduction position fixing mechanisms 14, 15, 16, 17 constitute a switching means.

  An incidental configuration of the present embodiment will be described.

  An air vent mechanism (not shown) may be provided near the center of the outer surface of the shell cover 6.

  A sealing material (not shown) is provided on the periphery of the outer surface of the shell cover 6. Thereby, the airtightness inside the shell is secured.

  A suspension jig 22 is provided on the outer surface of the shell cover 6 (see FIG. 5).

  On the other hand, the rod 5 is also provided with a hanging jig 23 (see FIG. 5). The hanging jig 23 may be provided on the upper frame 1 or the lower frame 2.

~ Drilling operation ~
During normal excavation, the shell cover 6 is fixed at the normal position (see FIGS. 1 and 3). In general, when the volume of the grab bucket is large, efficient work becomes possible.

  On the other hand, thin layer excavation is performed during finish excavation. The shell cover 6 is fixed at the volume reduction position (see FIGS. 2 and 4). Thereby, the volume of the grab bucket is reduced.

As an example, the case where the volume of 1.0 m ³ was reduced in volume to 0.8 m ^3. At the time of normal drilling drilling 1.0m ³ near the sediment. When excavating sediment 0.6 m ³ without volume reduction during thin layer excavation include water 0.4 m ^3. That is, the mud content is 60%.

On the other hand, when the volume is reduced to 0.8 m ³ during thin layer excavation, when 0.6 m ³ of earth and sand is excavated, 0.2 m ³ of water is contained. That is, the mud content is 75%.

  Thereby, a mud content rate can be improved significantly (in the above example, 25% UP).

  In addition, an example of a numerical value is shown for ease of explanation, and is not limited to this numerical value.

~ Switching operation ~
An operation (FIG. 1 → FIG. 2) for switching the shell cover 6 from the normal position to the volume reducing position will be described. FIG. 5 is an operation explanatory diagram.

  Hook the chain block 24 on the hanging jigs 22 and 23. By adjusting the length of the chain, tension is applied to the chain, and the shell cover 6 is suspended and supported by the rod 5. In this state, the pin 16 is removed from the pin holes 12 and 13 to release the normal position fixing.

  Further, the chain length of the chain block 24 is adjusted to rotate the shell cover 6 around the hinge 11. The shell cover 6 is engaged with the fixed position engagement plate 17 to stop the rotation.

  The pin 16 is inserted into the pin holes 14 and 15, and the shell cover 6 is fixed to the volume reducing position. The chain tension is released by adjusting the chain length, and the hooks of the chain block 24 are removed from the hanging jigs 22 and 23.

  The operation of switching the shell cover 6 from the volume reduction position to the normal position is performed in the reverse procedure to the above.

  A series of operations can be performed in the shell closed state (see FIG. 5) or the shell open state. All operations are performed from outside the shell, and workers do not work in the shell.

~effect~
The grab bucket of this embodiment can be easily reduced in volume and can greatly improve the mud content. As a result, the dredging work can be performed efficiently.

  The grab bucket of this embodiment is obtained by adding shell cover switching means to a general grab bucket. Each configuration of the shell cover switching means is such that its weight can be ignored compared to the partition plates and blocks in the prior art. That is, the suspended load is maintained, and the crane load of the dredger is not increased.

  In the switching operation of the present embodiment, it does not matter whether the shell is open or closed. That is, it is possible to work separately without interlocking with the dredger crane operation. In addition, all work is performed from outside the shell, and the work space is not limited. Furthermore, each work itself in the switching operation is easier than the conventional work. As a result, workability can be greatly improved. For example, in the prior art, what requires half a day can be switched in about one hour.

  The weight of each component of the shell cover switching means can be ignored. That is, there is no work for lifting a heavy object above the worker's head. Furthermore, work can be performed in a sufficiently large space. As a result, safety can be greatly improved.

~ Effects of the top board ~
In this embodiment, a rotation mechanism is used as the switching means. The turning mechanism is displaced in the angular direction and cannot be displaced in the radial direction. In other words, the angle of the shell cover 6 can be changed, but the length cannot be adjusted. On the other hand, the shape of the shell 4 is generally a substantially fan shape. As a result, when the length of the shell cover 6 is set based on the volume reduction position, the length becomes insufficient at the normal position. As a result, there is a possibility that the sealing property cannot be secured.

  On the other hand, when the length of the shell cover 6 is set so that the end faces of the pair of left and right shell covers 6 are engaged with each other with respect to the normal position, a part of the left and right shell covers 6 overlap each other at the volume reduction position. May be an obstacle.

  In contrast, the present embodiment includes a top plate 21. At the normal position, the outer surface of the shell cover 6 and the inner surface of the top plate 21 are engaged. Thereby, the airtightness inside a shell is ensured.

  A fixing jig having a pin hole 12 is extended on the outer surface of the top plate 21. That is, the top plate 21 suspends and supports the shell cover 6. Thereby, it can fix reliably in a normal position.

~ Modification ~
In the present embodiment, the pin hole 12, the pin hole 13 and the pin 16 constitute a normal position fixing mechanism, and the pin hole 14, the pin hole 15, the pin 16 and the fixed position engaging plate 17 constitute a volume reducing position fixing mechanism. However, several variations are possible.

  For example, by changing the position of the pin hole 14 of the side plate 41, the pin hole 13 on the outer surface of the shell cover 6 and the pin hole 15 on the inner surface of the shell cover 6 can be made common. That is, the configuration related to the pin hole 15 can be omitted. The pin hole 13, the pin hole 14, the pin 16, and the fixed position engaging plate 17 constitute a volume reducing position fixing mechanism.

  Further, the fixed position engaging plate 17 is not an essential component and may be omitted.

  Furthermore, although pin coupling is shown as an example of the normal position fixing mechanism and the volume reduction position fixing mechanism, the present invention is not limited to this.

  Moreover, although the hinge structure was shown as an example of a rotation mechanism, it is not limited to this. For example, rotation by pin coupling may be used.

Second Embodiment
FIG. 6 shows a schematic configuration of the grab bucket according to the second embodiment.

  The first embodiment is characterized by including the rotation mechanism 11 and the top plate 21, whereas the second embodiment is characterized by including the rotation mechanism 11 and shell cover expansion and contraction mechanisms 61 and 62. . That is, the top plate 21 is not necessary.

  The shell cover 6 has a bellows structure in which rigid members 61 and elastic members 62 are alternately repeated. That is, the elastic member 62 is configured to be extendable and contractible in the length direction.

  In the normal position, the elastic member 62 is extended. The shell cover 6 is fixed by a normal position fixing mechanism (reference numeral omitted).

  Similarly to the first embodiment, the shell cover 6 is suspended and supported via a chain block or the like. In this state, the normal position fixing is released. Thereby, the tensile force applied to the elastic member 62 is also released, and the elastic member 62 is shortened.

  Further, the shell cover 6 is rotated by the rotation mechanism 11. The shell cover 6 is engaged with the fixed position engagement plate 17 to stop the rotation.

  The shell cover 6 is fixed at the volume reduction position by the volume reduction position fixing mechanism (reference numeral omitted). The suspension support of the shell cover 6 is released.

  Thereby, the shell cover 6 can be switched to a normal position and a volume reduction position.

<Third Embodiment>
FIG. 7 shows a schematic configuration of the grab bucket according to the third embodiment.

  The first embodiment and the second embodiment are characterized by using a turning mechanism as the switching means, whereas the third embodiment does not use a turning mechanism. In the first embodiment and the second embodiment, one end of the shell cover 6 is fixed as a rotating shaft and the other end is freely opened, whereas in the third embodiment, both ends are fixed.

  The shell cover 6 is configured to be stretchable by an elastic material having appropriate rigidity.

  In addition, moderate rigidity means the grade which does not impair the muddy water suppression function of the shell cover 6.

  In the normal position, the shell cover 6 is extended. The shell cover 6 is fixed by a normal position fixing mechanism including the locking jig 63. The locking jig 63 is provided on the outer surface of the shell cover 6 and is locked to the top of the shell 4 main body at the normal position.

  Similarly to the first embodiment, the shell cover 6 is suspended and supported via a chain block or the like. In this state, the normal position fixing is released.

  Further, the suspension fulcrum is lowered to the volume reduction position while the shell cover 6 is suspended and supported. Accordingly, the tensile force acting on the shell cover 6 is gradually released, and the shell cover 6 is gradually shortened. The length of the shell cover 6 is set so as to be sealed at the volume reduction position.

  The shell cover 6 is fixed at the volume reduction position by a volume reduction position fixing mechanism (not shown) including the locking jig 63. The suspension support of the shell cover 6 is released.

  Thereby, the shell cover 6 can be switched to a normal position and a volume reduction position.

DESCRIPTION OF SYMBOLS 1 Upper frame 2 Lower frame 3 Rotating shaft 4 Shell 5 Rod 6 Shell cover 11 Hinge 12-15 Pin hole 16 Pin 17 Fixed position engagement plate 21 Top plate 22, 23 Hanging jig 24 Chain block 41 Side plate 42 Bottom plate 43 Extension plate 61 Rigid member 62 Elastic member 63 Locking jig

Claims (9)

The upper frame,
The lower frame,
A shell that is pivotally supported by the lower frame and opens and closes;
A rod connecting the upper frame and the shell;
A shell cover for sealing the upper side of the shell;
Switching means for switching the shell cover between a normal position and a volume reducing position;
A grab bucket comprising: The switching means is
A rotation mechanism for rotating the shell cover with respect to the shell;
A normal position fixing mechanism for fixing the shell cover in a normal position;
A volume reduction position fixing mechanism for fixing the shell cover to a volume reduction position;
The grab bucket according to claim 1, wherein: Further comprising a top plate connected to the top of the shell body,
The grab bucket according to claim 2, wherein the normal position fixing mechanism engages the shell cover and the top plate. The grab bucket according to claim 2 or 3, wherein the volume reduction position fixing mechanism fixes the shell cover at a position where end faces of the pair of left and right shell covers oppose each other. The said volume reduction position fixing mechanism contains the engagement pin which penetrates the engagement hole provided in the wall surface of the said shell, and the engagement hole provided in the said shell cover. A grab bucket according to claim 1. The grab bucket according to any one of claims 1 to 5, wherein the shell cover has a hanging jig on an outer surface. The grab bucket according to any one of claims 1 to 6, wherein the shell cover includes a sealing material on a peripheral edge of an outer surface. An upper frame, a lower frame, a pair of left and right shells, a rod,
A shell cover for sealing the upper side of the shell;
Switching means for switching the shell cover between a normal position and a volume reducing position with one side of the shell cover as a rotation axis;
A hanging jig provided on the outer surface of the shell cover;
A grab bucket volume changing method comprising:
The shell cover is suspended and supported on the upper frame, the lower frame, or the rod via the suspension jig,
A method for changing the volume of a grab bucket, wherein the shell cover is rotated in a suspended state to switch between a normal position and a volume reduction position. The grab according to claim 8, wherein an engagement pin is passed through an engagement hole provided in a wall surface of the shell and an engagement hole provided in the shell cover, and the shell cover is fixed at a volume reducing position. How to change the volume of the bucket.