JP4958321B1 - Grab bucket for firewood - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dredging grab bucket with a simple structure in which a front end locus of a shell is made substantially straight linear. <P>SOLUTION: A connection mechanism 9 which connects an upper frame 3 and shells 8 and 8 is composed of a bent link 30 which connects the upper part of the upper frame 3 and the shells 8 and 8, and a connection arm 31 which connects the lower part of the upper frame 3 and the shells 8 and 8. The top edge of the connection arm 31 is connected to the upper frame 3 through a bearing hole 40 formed by a long hole, long in vertical direction formed in the upper frame 3, and a pin 41 engaging with the bearing hole 40, and the pin 41 can be moved in vertical direction in the bearing hole 40. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to a dredging grab bucket that is used, for example, when dredging sediment or sludge accumulated on the seabed or the like.

  A problem of this type of grab bucket for dredging is that the excavation trace of the dredging may be in the shape of a concave groove due to the arc of the tip trajectory of the shell. That is, if the shell draws an arc-shaped tip locus and scoops earth and sand or sludge, it is inevitable that a deep groove corresponding to the tip locus of the shell is formed on the seabed by dredging. Thus, when a ditch | groove is formed in the seabed, the operation | work which leveles the seabed separately will be needed and will cause the fall of work efficiency.

  For this reason, in the grab bucket for dredging, various ideas have been conventionally made to make the tip trajectory of the shell substantially straight. For example, in Patent Document 1, a pair of hydraulic cylinders rotatably mounted on the lower frame is used. The shell is opened and closed, and the lower frame and the shell are connected by a link means so that the tip trajectory of the shell during the opening and closing operation is made substantially straight. In Patent Document 2, the tip trajectory of the shell is made straight by the expansion and contraction of the hydraulic cylinder that moves the lower frame up and down and the vertical displacement of the bucket.

Japanese Patent No. 3270991 (Claim 1, paragraph number 0023, FIG. 1) JP 2008-75441 A (Claim 1, FIG. 1)

  However, in the grab bucket described in Patent Document 1, since a relatively expensive hydraulic cylinder is used as an actuator for opening and closing the shell, it is inevitable that the manufacturing cost of the grab bucket increases. In addition, since a complicated link mechanism is employed as a connection mechanism between the lower frame and the shell, it is inevitable that the manufacturing cost of the grab bucket increases in this respect as well. The same applies to the grab bucket described in Patent Document 2, and it is inevitable that the manufacturing cost of the grab bucket increases as long as the hydraulic cylinder is used as an actuator for opening and closing the shell. In addition, it is necessary to strictly control both the expansion / contraction displacement of the hydraulic cylinder and the vertical displacement of the bucket, which is disadvantageous in that the control is extremely complicated.

  The present invention has been made to solve the problems of the conventional grab bucket as described above, and can be used to make the tip trajectory of the shell substantially straight with a simpler configuration. The purpose is to provide grab buckets.

A glove bucket 1 for a bag according to the present invention includes an upper frame 3 suspended by a suspension wire 2, a lower frame 6 suspended by the upper frame 3 via a pulley mechanism 5, and a shell shaft extending in the front-rear direction. 7 includes a pair of left and right shells 8 and 8 that are pivotally supported by the lower frame 6 via a pair 7, and a connection mechanism 9 that connects the upper frame 3 and the shells 8 and 8. The pulley mechanism 5 includes an upper sheave 14 provided on the upper frame 3, a lower sheave 20 provided on the lower frame 6, and an opening / closing wire 4 wound around the upper and lower sheaves 14, 20. Thus, the shells 8 and 8 can be opened and closed by moving the lower frame 6 up and down.
The connecting mechanism 9 includes a pair of left and right refracting links 30 that connect the upper portion of the upper frame 3 and the left and right shells 8 and 8, and a connecting arm 31 that connects the lower portion of the upper frame 3 and the left and right shells 8 and 8. Become. The upper end of the connecting arm 31 is connected to the upper frame 3 via a bearing hole 40 formed by a long elongated hole in the vertical direction and a pin 41 that engages with the bearing hole 40. It is connected to the shells 8 and 8 via a rotating shaft 42. The pin 41 is between a lower end position received by the lower end inner edge of the bearing hole 40, a midway position that is not in contact with the lower end inner edge and the upper end inner edge of the bearing hole 40, and an upper end position received by the upper end inner edge of the bearing hole 40. It is supported by the upper frame 3 so that it can be displaced. The left and right shells 8 and 8 are configured to be swingable around the shell shaft 7 between a fully open posture in which the opposed surfaces are directed downward and a fully closed posture in which the opposed surfaces are in contact with each other. When the shells 8 and 8 are in the fully open position and the fully closed position, the pin 41 is located at the lower end position in the bearing hole 40, and when the shells 8 and 8 are between the fully open position and the fully closed position, 41 is configured to be located in the middle position or the upper end position in the bearing hole 40.

  The refraction link 30 includes a first arm 33 fixed to the upper frame 3 via an upper turning shaft 32, a second arm 35 fixed to the shell 8 via a lower turning shaft 34, and free ends of both arms 33 and 35. It can be configured by a refracting pin 36 that refractably connects each other, and the lower turning shaft 34 of the refracting link 30 can also serve as the turning shaft 42 of the connecting arm 31.

  Guide grooves 16 that allow the lower frame 6 to move up and down are provided on the front and rear surfaces of the upper frame 3, and the horizontal movement of the lower frame 6 during the up and down movement is restricted along the left and right outer edges of the guide groove 16. Therefore, it is possible to take a form in which a regulating body 17 is provided.

  A form in which a suspension bracket 10 for supporting a suspension ring to which the suspension wire 2 is connected is provided at four positions on the upper frame 3 along the front and rear edges and the left and right edges.

As a result of studying the tip trajectory of the shell from the fully open posture to the fully closed posture (see FIG. 7) in the conventional grab bucket 100, the present inventors can roughly divide the tip trajectory into the following three stages. I got the knowledge. That is, the tip trajectory of the shells 101 and 101 is greater in the descending degree of the tip trajectory of the shell 101 than immediately after the start of the closing operation (the opening operation early stage) to the middle of the closing operation, rather than the shell shaft 103 of the lower frame 102 rising. Therefore, when the shell 101 is brought closer to the closed state from the first stage (see FIGS. 8A to 8C) when the tip trajectory of the shell 101 is lowered (see FIGS. 8A to 8C), the shell 101 is closed. The second stage in which the tip locus of the shell 101 substantially coincides with the descending degree of the tip locus of the shell 101 and the rising degree of the shell shaft 103 (FIGS. 8C to 8D). When the shell 101 is in a substantially fully closed posture at the end of the closing operation, the rising degree of the shell shaft 103 becomes larger than the lowering degree of the tip trajectory of the shell 101 accompanying the closing operation. 1 tip locus to obtain a finding that can be divided into a third stage of increasing (FIG. 8 (d) ~ (f)).
In addition, in particular, if the tip trajectory of the shell 101 in the first and third stages can be controlled, the tip trajectory of the shell 101 from the fully open position to the fully closed position can be made substantially straight. Obtaining knowledge, the present invention has been completed.

  More specifically, in the present invention, in the grab bucket 1 for eaves that moves the lower frame 6 up and down with respect to the upper frame 3 using the pulley mechanism 5, the connecting mechanism 9 that connects the upper frame 3 and the shells 8 and 8. Is constituted by a refraction link 30 that connects the upper part of the upper frame 3 and the shells 8 and 8 and a connecting arm 31 that connects the lower part of the upper frame 3 and the shells 8 and 8. Then, the upper end of the connecting arm 31 is connected to the upper frame 3 via a bearing hole 40 formed by a vertically long slot formed in the upper frame 3 and a pin 41 engaged with the bearing hole 40, The pin 41 is configured to move up and down in the bearing hole 40.

  In the grab bucket according to the present invention configured as described above, as shown in FIG. 6A, when the lower frame 6 is positioned downward and the shells 8 and 8 are in the fully open posture, the shell 8 Under the load of 8, the pin 41 of the connecting arm 31 is at the lower end position where it is received by the lower end inner edge of the bearing hole 40. From this state, when the opening / closing wire 4 is wound up by the pulley mechanism 5 and the lower frame 6 is raised (when the closing operation is started), the shell shaft 7 is raised, as shown in FIGS. 6 (b) and 6 (c), The shells 8 and 8 are closed. As the shells 8 and 8 are closed, the turning shaft 42 at the lower end of the connecting arm 31 approaches the center of the grab bucket in the left-right direction, and the angular posture of the connecting arm 31 approaches a vertical posture. For this reason, the pin 41 is lifted and moved in the bearing hole 40 by the tensioning action of the connecting arm 31 starting from the turning shaft 42, and moves to a midway position that is not in contact with the lower end inner edge and the upper end inner edge of the bearing hole 40. .

  As described above, in the conventional grab bucket, the descending degree of the tips of the shells 101 and 101 is large and draws an arc-shaped trajectory from the first stage of the closing operation to the first stage of the closing operation. On the other hand, in the grab bucket according to the present invention, the pin 41 of the connecting arm 31 is configured to be movable in the long and long bearing hole 40 in the vertical direction. 7 as well as the pin 41 can be moved upward. From the above, since the large descending degree of the tips of the shells 8 and 8 from the beginning to the middle of the closing operation can be absorbed by the rise of the shell shaft 7 and the rise of the pin 41, the tip trajectories of the shells 8 and 8 are substantially straight. Can be used.

  When the lower frame 6 is further raised from the state shown in FIG. 6C, the pin 41 is displaced to the upper end position that contacts the inner edge of the upper end of the bearing hole 40 (see FIGS. 6D and 6E). In other words, the upper limit in the bearing hole 40 of the pin 41 is restricted, and only the shell shaft 7 rises as the lower frame 6 rises. Since the descending state of the tips of the shells 8 and 8 immediately before the end of the closing operation from the middle of the closing operation is absorbed by the rise of the shell shaft 7, the locus of the tips of the shells 8 and 8 is substantially straight.

  Immediately before the closing operation is finished, the angular posture of the connecting arm 31 approaches a vertical posture, so that the tension action starting from the rolling shaft 42 is released, and the pin 41 moves downward from the upper end position to the lower end position in the bearing hole 40. (Refer FIG.6 (f)). By the downward movement of the pin 41, it is possible to absorb the rise of the tips of the shells 8 and 8 accompanying the rise of the shell shaft 7, so that the locus of the tips of the shells 8 and 8 can be made substantially straight. That is, in the present invention, the rise of the tip of the shell 8 or 8 in the third stage of the final stage of the closing operation, which is unavoidable in the conventional grab bucket, is absorbed by the downward movement of the pin 41 in the present invention. -The tip locus of 8 can be made substantially straight.

  As described above, in the present invention, the upper frame 3 is formed with the long and long bearing hole 40 which is long in the vertical direction, and in the bearing hole 40, the lower end of the upper frame 3 and the shells 8 and 8 are connected. Since the pin 41 of the arm 31 is configured to be movable in the vertical direction, it was difficult in the prior art to make the tip locus of the shells 8 and 8 straight, from the early stage of the closing operation to the middle stage (first stage), And the tip locus of the shells 8 and 8 in the final stage of the closing operation (third stage) can be made substantially straight. Accordingly, the position of the shell shaft 7 as the lower frame 6 moves up and down and the position of the pin 41 in the bearing hole 40 in the entire closing operation from the fully open position to the fully closed position of the shells 8 and 8 are defined. Because the tip locus of the shells 8 and 8 can be made substantially straight, the tip locus of the shells 8 and 8 is inevitable with the conventional bag grab bucket, and is caused by the arc shape. The problem of forming a ditch on the seabed can be reliably solved. Thereby, since the sea bottom can be dredged flat, the operation | work which leveles the sea bottom becomes unnecessary, and dredging work can be performed more efficiently.

  Further, in the grab bucket 1 according to the present invention, the torque from the pulley mechanism 5 for lowering the lower frame 6 to open and close the shells 8 and 8 is released by the pin 41 floating in the bearing hole 40. The torque is not directly applied to the shells 8 and 8. For this reason, according to the present invention, the tips of the shells 8 and 8 do not dig deeply into the bottom of the sea, in other words, without forming a ditch-like trench excavation trace on the bottom of the sea, and tracing the bottom of the sea. It is also excellent in that the so-called “thin layer dredging” can be surely performed by scooping and scooping soil and sand of a predetermined thickness.

  In the present invention, since the upper end of the upper frame 3 and the shells 8 and 8 are connected by the refraction link 30, the refraction link 30 hinders the rotational rotation of the shells 8 and 8 around the shell shaft 7. Does not occur.

  In addition, as shown in Patent Documents 1 and 2, in a grab bucket in which a shell opening / closing element (actuator) is a hydraulic cylinder, it is possible to accurately control the position of the lower frame and accurately control the tip trajectory of the shell. Although possible, in the forms of these Patent Documents 1 and 2, the cost increases as much as the hydraulic cylinder is adopted, and there is a disadvantage that the overall cost of the grab bucket is increased. On the other hand, according to the present invention, since the pulley mechanism 5 which is cheaper than the hydraulic cylinder is employed as the opening and closing element of the shells 8 and 8, an increase in the manufacturing cost of the grab bucket 1 can be suppressed. In addition, a connecting arm 31 that connects the lower portion of the upper frame 3 and the shells 8 and 8 that is not included in the conventional grab bucket is adopted, and a connecting mechanism between the connecting arm 31 and the upper frame 3 is used in the upper frame 3. Since it has a simple configuration that adopts a long hole-shaped bearing hole 40 and controls the tip locus of the shells 8 and 8 in a straight line by these, the function of controlling the tip locus of the shells 8 and 8 while suppressing the manufacturing cost. It is excellent also in the point which can obtain the grab bucket 1 provided with.

  If the lower turning shaft 34 of the refraction link 30 also serves as the turning shaft 42 of the connecting arm 31, the number of parts can be reduced as compared with the case where the rotating shaft 42 of the connecting arm 31 is provided separately from the lower turning shaft 34. Thus, the grab bucket 1 can be obtained at a lower cost.

  In the grab bucket 1 according to the present invention, since the upper part of the upper frame 3 and the shells 8 and 8 are connected by the refraction link 30, almost no load of the shells 8 and 8 is received on the upper frame 3 via the refraction link 30. Instead, most of the load on the shells 8 and 8 is received by the upper frame 3 via the lower frame 6 and the connecting arm 31. That is, in the present invention, a large load is also applied to the lower frame 6. In the present invention, since the pin 41 of the connecting arm 31 is configured to be movable in the bearing hole 40, if the lower frame 6 is displaced in the left-right direction with respect to the upper frame 3, the pin 41 is moved in the bearing hole 40 of the pin 41. There is a possibility that the smooth movement of the hindered. Therefore, as in the present invention, guide grooves 16 that allow the lower frame 6 to move up and down are provided on the front and rear surfaces of the upper frame 3, and along the left and right outer edges of the guide groove 16, the left and right sides of the lower frame 6 are moved up and down. If the restricting body 17 for restricting the movement in the direction is provided, the lower frame 6 receiving a large amount of load can be moved up and down along the restricting body 17 without being displaced. The pin 41 can be moved smoothly. As a result, it is possible to prevent the pin 41 from being stopped inadvertently in the bearing hole 40, so that it is possible to obtain the grab bucket 1 having excellent reliability while suppressing the occurrence of malfunction.

  If suspension brackets 10a to 10d for supporting a suspension ring to which the suspension wire 2 is connected are provided at four positions on the upper surface of the upper frame 3 along the front and rear edges and the left and right edges, these four suspension brackets 10a. The suspension posture of the grab bucket 1 with respect to the crane can be displaced by 90 degrees by connecting the suspension wire 2 to the suspension ring of the two suspension support brackets 10 selected from 10d to 10d. it can. Accordingly, the dredging operation can be advanced by changing the hanging posture of the grab bucket 1 without displacing the posture of the crane.

It is a front view of the grab bucket for straws concerning the present invention. It is a side view of the principal part of the grab bucket for straws concerning the present invention. It is a side view of the grab bucket for straws concerning the present invention. It is the sectional view on the AA line of FIG. It is a schematic front view for demonstrating operation | movement of the grab bucket for straws which concerns on this invention. (A)-(f) is a schematic front view for demonstrating the operation | movement of the grab bucket for straws concerning this invention. It is a schematic front view for demonstrating operation | movement of the conventional grab bucket for straw. (A)-(f) is a schematic front view for demonstrating operation | movement of the conventional grab bucket for straw.

  1 to 6 show an embodiment of a glove bucket for a basket according to the present invention. As shown in FIGS. 1 and 3, the grab bucket 1 is suspended by two suspension wires 2 suspended from a crane of a hoist ship (not shown). The grab bucket 1 is provided on an upper frame 3 to which two suspension support wires 2 are connected, a lower frame 6 that is suspended by an upper frame 3 via a pulley mechanism 5 including an opening / closing wire 4, and a lower frame 6. And a pair of left and right shells 8 and 8 supported by the shell shaft 7 so as to be freely opened and closed, and a connecting mechanism 9 for connecting the upper frame 3 and the left and right shells 8 and 8. The suspension support wire 2 and the open / close wire 4 are connected to the winch via cranes, respectively, and the hoisting / lowering operation of the grab bucket 1 and the opening / closing operation of the shells 8 and 8 are performed by hoisting or lowering the winch. It can be carried out. In the present invention, front / rear, left / right, and upper / lower follow the cross arrows shown in the figure and the front / rear, left / right, and upper / lower indications shown near each arrow.

  As shown in FIGS. 1 and 3, suspension brackets 10 a to 10 d for supporting a suspension ring to which the suspension wires 2 and 2 are connected are provided at four positions on the upper surface of the upper frame 3. Of these four suspension brackets 10a to 10d, the pair of front and rear suspension brackets 10a and 10b are provided along the front and rear edges of the upper surface of the upper frame 3, and the pair of left and right suspension brackets 10c and 10d are It is provided along the left and right edges of the upper surface of the upper frame 3. 1 and 3 show a form in which a suspension ring is fixed to a pair of left and right suspension brackets 10c and 10d, and a suspension wire 2 is connected to each suspension ring. As described above, when a total of four suspension brackets 10a to 10d are provided on the front, rear, and left and right of the upper surface of the upper frame 3, a pair of front and rear, or left and right selected from these four suspension brackets 10a to 10d. By connecting the suspension wire 2 to the suspension ring of the pair of two suspension brackets 10, the suspension posture of the grab bucket 1 with respect to the crane can be easily and reliably displaced by 90 degrees. Accordingly, the dredging operation can be advanced by changing the hanging posture of the grab bucket 1 without displacing the posture of the crane.

  As shown in FIGS. 1 and 4, the upper frame 3 includes a pair of front and rear frames 11 and 12, a spacer (not shown) that extends in the front and rear direction and connects the front and rear frames 11 and 12, and the front and rear frames 11 and 12. It consists of a top frame 13 connecting the upper ends, and is formed in a square frame shape having an opening in the center in plan view. The previous suspension bracket 10 is fixed to the upper surface of the top frame 13, and the upper sheave 14 is fixed to the lower surface of the top frame 13. The top plate frame 13 is formed with an opening that allows the opening / closing wire 4 to be inserted therethrough. Each of the front and rear frames 11 and 12 is formed in a double plate structure in which two plate bodies 15 and 15 are connected via a spacer (not shown). Each of the front and rear frames 11 and 12 is provided with a guide groove 16 that allows the lower frame 6 to move up and down while allowing the bearing bracket 22 of the lower frame 6 to project outward. In addition, on the outer surfaces of the front and rear frames 11 and 12, a restricting body 17 is provided for restricting the free movement of the lower frame 6 in the left-right direction when moving up and down. The restricting body 17 is a bar extending in the vertical direction, and is mounted and fixed to the outer surfaces of the front and rear frames 11 and 12 along the left and right outer edges of the guide groove 16.

  A refraction link 30 described later is connected to the upper end of the upper frame 3, and a connecting arm 31 is connected to the lower end of the upper frame 3. Details of the coupling mechanism 9 including the refractive link 30 and the coupling arm 31 will be described later.

  As shown in FIGS. 1 to 4, the lower frame 6 includes a base frame 21 to which the lower sheave 20 is attached, and a pair of front and rear bearing brackets 22 and 22 extending from the base frame 21 in the front-rear direction. A lower sheave 20 is fixed to the upper surface of the base frame 21, and the lower sheave 20, the upper sheave 14 provided on the upper frame 3, and the opening / closing wire 4 wound around the upper and lower sheaves 14, 20, A pulley mechanism 5 is configured. The shells 8 and 8 can be opened and closed by moving the lower frame 6 up and down via the opening and closing wire 4.

  As shown in FIGS. 2 and 4, the bearing brackets 22, 22 protrude in the front / rear outer direction through guide grooves 16, 16 provided in the front / rear frames 11, 12 of the upper frame 3. A shell shaft 7 extending in the front-rear direction is attached to each of the bearing brackets 22, and a pair of left and right shells 8, 8 are attached around the shell shaft 7 so as to be openable and closable.

  Each shell 8 rotates a shell main body 24, a pair of front and rear shell arms 25, 25 for connecting the shell main body 24 to the lower frame 6, a refractive link 30 and a lower end of the connecting arm 31 constituting the connecting mechanism 9. And four arm brackets 26a to 26d for connection via shafts 34 and 42. Arm brackets 26 a and 26 d at both front and rear ends of the four arm brackets 26 a to 26 d are provided at the front and rear edges of the shell body 24.

  As described above, the upper portion of the upper frame 3 and the shell 8 are connected by the refractive link 30, and the lower portion of the upper frame 3 and the shell 8 are connected by the connecting arm 31. Specifically, as shown in FIG. 3, the upper portion of the upper frame 3 and the left and right shells 8 are connected by a single refracting link 30, and the lower portion of the upper frame 3 as shown in FIG. And the left and right shells 8 are connected by a pair of front and rear connecting arms 31.

  As shown in FIGS. 1 and 3, each refractive link 30 includes a first arm 33 fixed to the upper frame 3 via a pair of front and rear upper turning shafts 32 and 32, and a shell 8 via a lower turning shaft 34. The second arm 35 is fixed, and a pair of front and rear refracting pins 36 and 36 that refractably connect the free ends of the arms 33 and 35 are configured. Each upper turning shaft 32 is mounted between two plate bodies 15 and 15 constituting the frames 11 and 12 before and after the upper frame 3, respectively. As shown in FIG. 3, each first arm 33 includes a pair of longitudinal rods 33 a and 33 a that are configured to be swingable around the upper rotation shafts 32 and 32 and extend in the vertical direction, and the longitudinal rods 33 a and 33 a. It is composed of two upper and lower horizontal rods 33b and 33c extending in the horizontal direction so as to be connected. The second arm 35 configured to swing around the refraction pins 36 and 36 provided at the lower ends of the vertical rods 33a and 33a includes a hollow trapezoidal base 35a extending in the horizontal direction and four front and rear positions of the base 35a. The four connecting rods 37 (37a to 37d) extend downward and are connected to the arm brackets 26 (26a to 26d) of the shell 8 via the lower turning shafts 34 (34a to 34d).

  The upper ends of the two connecting arms 31 that connect the lower portion of the upper frame 3 and the left and right shells 8 are provided with a bearing hole 40 provided in the upper frame 3 as a long hole in the vertical direction, and the bearing hole 40. The pin 41 is connected to the upper frame 3 via a pin 41 engaged with the pin 41, and the pin 41 can move in the vertical direction within the bearing hole 40. Further, the lower end of the connecting arm 31 is connected to the shell 8 via the rotating shaft 42. As shown in FIG. 2, the bearing hole 40 is formed in each of the two plate bodies 15 constituting the front and rear frames 11 and 12 of the upper frame 3. Here, the two lower turning shafts 34 b and 34 c located at the front and rear center portions of the bending link 30 also serve as the turning shaft 42 of the connecting arm 31.

  In the grab bucket 1 having the above-described configuration, the grab bucket 1 is moved right above the dredging work position, the open / close wire 4 is wound down, and the shells 8 and 8 are in the fully open posture (FIG. 6). (See (a)). Further, the suspension support wire 2 is wound down, and the grab bucket 1 is lowered to the dredging work position in the sea. Next, in a state where the grab bucket 1 is stopped at the dredging work position, the open / close wire 4 is wound up so that the shells 8 and 8 are closed while grasping the sediment on the seabed. After the shells 8 and 8 have grasped the deposit, the suspension wire 2 and the opening / closing wire 4 are simultaneously wound up so that the opening / closing wire 4 is not loosened and the grab bucket 1 is pulled up to the sea. The raised grab bucket 1 is moved onto the transport ship, the open / close wire 4 is lowered, the shells 8 and 8 are opened, and the grabbed deposit is loaded. The saddle work is performed by repeating the above work while sequentially changing the saddle position.

  In addition, in the scissor grab bucket 1 according to the present embodiment, the trajectory (tip trajectory) defined by the tips of the shells 8 and 8 from the fully open position to the fully closed position is substantially straight. Is noticed. The opening / closing operation | movement of this shell 8 * 8 is demonstrated with reference to FIG. 5 and FIG. As shown in FIG. 6A, in a state where the lower frame 6 is positioned below and the shells 8 and 8 are in a fully open position, the pin 41 of the connecting arm 31 is a bearing under the load of the shells 8 and 8. The lower end position of the hole 40 is at the lower end position. From this state, when the opening / closing wire 4 is wound up by the pulley mechanism 5 and the lower frame 6 is raised (when the closing operation is started), the shell shaft 7 is raised, as shown in FIGS. 6 (b) and 6 (c), The shells 8 and 8 are closed. As the shells 8 and 8 are closed, the turning shaft 42 at the lower end of the connecting arm 31 approaches the center of the grab bucket 1 in the left-right direction, and the angular posture of the connecting arm 31 approaches a vertical posture. For this reason, the pin 41 is moved up in the bearing hole 40 by the tensioning action of the connecting arm 31 starting from the rotating shaft 42. As described above, when the pin 41 of the connecting arm 31 is configured to be movable in the long and long bearing hole 40 that is vertically long, not only the shell shaft 7 but also the pin 41 can be moved as the lower frame 6 rises. Can also be absorbed by the rise of the shell shaft 7 and the pin 41, so that the shells 8 and 8 can be absorbed. The tip trajectory can be made substantially straight.

  When the lower frame 6 is further raised from the state shown in FIG. 6C, the pin 41 is displaced to the upper end position that contacts the inner edge of the upper end of the bearing hole 40 (see FIG. 6D). In other words, the upper limit in the bearing hole 40 of the pin 41 is restricted, and only the shell shaft 7 rises as the lower frame 6 rises. Since the descending state of the tips of the shells 8 and 8 immediately before completion of the closing operation from the middle of the closing operation is absorbed by the rise of the shell shaft 7, the locus of the tips of the shells 8 and 8 is substantially linear.

  Immediately before the closing operation is finished, the angular posture of the connecting arm 31 approaches a vertical posture, so that the tension action starting from the rolling shaft 42 is released, and the pin 41 moves downward from the upper end position to the lower end position in the bearing hole 40. (Refer FIG.6 (f)). By the downward movement of the pin 41, it is possible to absorb the rise of the tips of the shells 8 and 8 accompanying the rise of the shell shaft 7, so that the locus of the tips of the shells 8 and 8 can be made substantially straight. That is, the rise of the tip of the shell 8 or 8 at the end of the closing operation is absorbed by the downward movement of the pin 41, and the tip locus of the shell 8 or 8 can be made substantially straight.

  As described above, in the grab bucket for scissors according to the present embodiment, the upper frame 3 is formed with a long and long bearing hole 40 in the vertical direction, and the lower end of the upper frame 3 and the shell 8 are formed in the bearing hole 40.・ Because the pin 41 of the connecting arm 31 that connects 8 is movable in the vertical direction, it was difficult in the past to make the tip locus of the shells 8 and 8 straight. The tip trajectories of the shells 8 and 8 in the middle stage (first stage) and the closing stage (third stage) can be made substantially straight (see FIGS. 5 and 6). Accordingly, the position of the shell shaft 7 as the lower frame 6 moves up and down and the position of the pin 41 in the bearing hole 40 in the entire closing operation from the fully open position to the fully closed position of the shells 8 and 8 are defined. Because the tip locus of the shells 8 and 8 can be made substantially straight, the tip locus of the shells 8 and 8 is inevitable with the conventional bag grab bucket, and is caused by the arc shape. The problem of forming a ditch on the seabed can be reliably solved. Thereby, since the sea bottom can be dredged flat, the operation | work which leveles the sea bottom becomes unnecessary, and dredging work can be performed more efficiently.

  Further, in the grab bucket 1 for scissors according to the present embodiment, the pin 41 floats in the bearing hole 40 with torque from the pulley mechanism 5 for lowering the lower frame 6 to open and close the shells 8 and 8. Therefore, the torque is not directly applied to the shells 8 and 8. For this reason, according to the present embodiment, the tip of the shells 8 and 8 do not dig deeply into the bottom of the sea, in other words, the groove bottom is not formed on the sea bottom, and the sea bottom is traced. It is also excellent in that a so-called “thin layer cocoon” can be surely carried out by scoring the soil and scooping up soil and sludge having a predetermined thickness.

  Further, according to the invention according to the present embodiment, the pulley mechanism 5 which is less expensive than the hydraulic cylinder is employed as the opening and closing element of the shells 8 and 8, so that an increase in the manufacturing cost of the grab bucket 1 can be suppressed. In addition, a connecting arm 31 that connects the lower portion of the upper frame 3 and the shells 8 and 8 is adopted, and a long hole-like bearing hole 40 is provided in the upper frame 3 as a connecting mechanism between the connecting arm 31 and the upper frame 3. The grab bucket 1 having the control function of the tip trajectory of the shells 8 and 8 is obtained while reducing the manufacturing cost because the tip trajectory of the shells 8 and 8 is controlled in a substantially straight line. It is also excellent in that it can.

  If the lower turning shaft 34 of the refraction link 30 also serves as the turning shaft 42 of the connecting arm 31, the number of parts can be reduced as compared with the case where the rotating shaft 42 of the connecting arm 31 is provided separately from the lower turning shaft 34. Thus, the grab bucket 1 can be obtained at a lower cost.

  A guide groove 16 that allows the lower frame 6 to move up and down is provided on the front and rear surfaces of the upper frame 3, and the lateral movement of the lower frame 6 during the up and down movement is restricted along the left and right outer edges of the guide groove 16. If the restriction body 17 is provided, the lower frame 6 that receives a large amount of load can be moved up and down without being displaced along the restriction body 17, so that the pin 41 moves smoothly in the bearing hole 40. Can be made. As a result, it is possible to prevent the pin 41 from being stopped inadvertently in the bearing hole 40, so that it is possible to obtain the grab bucket 1 having excellent reliability while suppressing the occurrence of malfunction.

  The configurations of the upper frame 3 and the lower frame 6 are not limited to those shown in the above embodiment. The configurations of the first and second arms and the like that constitute the refractive link 30 are not limited to those shown in the above embodiment.

DESCRIPTION OF SYMBOLS 1 Grab bucket 2 Suspension support wire 3 Upper frame 4 Opening / closing wire 5 Pulley mechanism 6 Lower frame 7 Shell shaft 8 Shell 9 Connection mechanism 10 Suspension bracket 14 Upper sheave 16 Guide groove 17 Regulator 20 Lower sheave 30 Refraction link 31 Connection arm 32 Upper turning shaft 33 First arm 34 Lower turning shaft 35 Second arm 36 Refractive pin 40 Bearing hole 41 Pin 42 Turning shaft

Claims (4)

An upper frame (3) suspended by a suspension wire (2), a lower frame (6) suspended by an upper frame (3) via a pulley mechanism (5), and a shell shaft extending in the front-rear direction ( 7) a pair of left and right shells (8, 8) pivotally supported by the lower frame (6) via 7), and a connecting mechanism (9) for connecting the upper frame (3) and the shell (8, 8). Including
The pulley mechanism (5) hangs around an upper sheave (14) provided on the upper frame (3), a lower sheave (20) provided on the lower frame (6), and upper and lower sheaves (14, 20). An open / close wire (4), and the open / close wire (4) to open and close the lower frame (6) to open and close the shell (8.8).
The connection mechanism (9) includes a pair of left and right refractive links (30) that connect the upper part of the upper frame (3) and the left and right shells (8, 8), and the lower part of the upper frame (3) and the left and right shells (8 -It comprises a connecting arm (31) that connects 8),
The upper end of the connecting arm (31) is connected to the upper frame (3) via a bearing hole (40) formed by a long hole extending vertically and a pin (41) engaged with the bearing hole (40). The lower end of the connecting arm (31) is connected to each shell (8, 8) via a turning shaft (42),
The pin (41) is provided at the lower end position received by the lower end inner edge of the bearing hole (40), the midway position in non-contact with the lower end inner edge and the upper end inner edge of the bearing hole (40), and the upper end inner edge of the bearing hole (40). It is supported by the upper frame (3) so that it can be displaced between the upper end position to be received,
The left and right shells (8, 8) are configured to be swingable around the shell axis (7) between a fully open posture in which the opposed surfaces are directed downward and a fully closed posture in which the opposed surfaces are in contact with each other. ,
When the shell (8, 8) is in the fully open position and the fully closed position, the pin (41) is located at the lower end position in the bearing hole (40), and the shell (8.8) is in the fully open position and the fully closed position. It is comprised so that a pin (41) may be located in an intermediate position or an upper end position within a bearing hole (40) when it exists in between. The refraction link (30) includes a first arm (33) fixed to the upper frame (3) via an upper turning shaft (32), and a second arm fixed to the shell (8) via a lower turning shaft (34). It consists of an arm (35) and a refracting pin (36) that flexibly connects the free ends of both arms (33, 35).
2. The bag grab bucket according to claim 1, wherein the lower turning shaft (34) of the refractive link (30) also serves as the turning shaft (42) of the connecting arm (31).   Guide grooves (16) that allow the lower frame (6) to move up and down are provided on the front and rear surfaces of the upper frame (3), and the lower frame (during the up and down movement) along the left and right outer edges of the guide groove (16). The bag grab bucket according to claim 1 or 2, wherein a regulating body (17) for regulating the movement in the left-right direction of 6) is provided.   The suspension bracket (10) for supporting the suspension ring to which the suspension wire (2) is connected is provided at four positions on the upper frame (3) along the front and rear edges and the left and right edges. The grab bucket for straws in any one of 3.

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