Auxiliary tool on the overhead crane

Abstract

To provide a pile lifting auxiliary tool capable of appropriately holding a lifting state of a pile.SOLUTION: A derricking truck 1 (a pile lifting auxiliary tool) holds a lower end of a pile when erecting the pile, and has a body 10, wheels 13 fitted to the body 10, and holding members 14 being multiple juxtaposed holding members rotating in a holding state of the pile following erection of the pile. The multiple holding members 14 are slidable in a direction of changing an arrangement interval, and rotate independently.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a pile lifting auxiliary device that holds the lower end of a pile when lifting it. [Background technology]

[0002] Conventionally, pile lifting auxiliary devices that hold the bottom end of a pile, such as a steel pipe pile, a steel pipe sheet pile, or a steel sheet pile, when the pile is lifted by a crane, have been known. Patent Documents 1 and 2 describe auxiliary devices used when lifting a steel sheet pile. The auxiliary devices described in these documents have a configuration including two holding members that sandwich the web at the bottom end of the steel sheet pile. Patent Document 3 describes an auxiliary device used when lifting a pipe pile, and includes a connecting part that is detachably connected to the bottom edge of the pipe pile. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 5-95933 [Patent Document 2] China Publication No. 104909271 [Patent Document 3] JP 2019-85845 A Summary of the Invention [Problem to be solved by the invention]

[0004] The auxiliary devices described in Patent Documents 1 and 2 have two connecting holding members that rotate as one unit. Therefore, depending on the position of the pile when it is lifted, a torsional force could be transmitted to the auxiliary device holding the lower end of the pile, causing the auxiliary device to fall over.

[0005] The auxiliary device described in Patent Document 3 has a configuration in which the lower end of the pipe pile is clamped between an outer retaining body and an inner retaining body, so there was the same problem as above in that the torsional force of the pile was transmitted to the auxiliary device.

[0006] In addition, there is known a steel pipe pile equipped with a bit at the tip to enable the steel pipe pile to be pressed into hard ground. However, there is a problem with such a steel pipe pile equipped with a bit, in that if a retaining member is located at the location of the bit, the tip of the steel pipe pile cannot be properly retained.

[0007] In view of the above background, an object of the present invention is to provide a pile lifting auxiliary device that can appropriately assist in lifting a pile. [Means for solving the problem]

[0008] The pile lifting aid of the present invention is a pile lifting aid that holds the lower end of a pile when it is being erected, and comprises a main body, wheels attached to the main body, and a plurality of holding members arranged in parallel which rotate while holding the pile as the pile is erected, and the plurality of holding members are slidable in a direction that changes the spacing between them, and are configured to rotate independently of each other.

[0009] In this way, by having the multiple holding members rotate independently of each other, even if a torsional force occurs in the pile when it is lifted, the holding members follow the movement of the pile to absorb the torsional force and suppress the transmission of the torsional force to the main body. In addition, since the holding members can slide in a direction to change the arrangement interval, the holding position of the bottom end of the pile can be adjusted. For example, in the case of a steel pipe pile with a bit at the tip, the bottom end of the pile can be properly held by adjusting the position of the holding member so as to avoid the position of the bit.

[0010] The pile lifting aid of the present invention may further include a support shaft for supporting the holding member rotatably and slidably on an upper portion of the body. With this configuration, it is possible to realize both rotation and sliding of the holding member.

[0011] The main body of the pile lifting aid of the present invention may include a base having the wheels, and a turntable having the support shaft and rotatable relative to the base. With this configuration, the holding member rotates relative to the cart, so that the twisting force of the pile can be released by the rotation of the turntable.

[0012] The main body of the pile lifting aid of the present invention may include a base having the wheels, and a table having the support shaft and detachable from the base. With this configuration, when either the base or the holding member breaks down, the broken one can be replaced, improving maintainability. In addition, the pile lifting aid can be configured by appropriately selecting a combination of the base and the holding member depending on the traveling environment or the size of the pile to be held.

[0013] The holding member of the pile lifting aid of the present invention may be provided with a connecting portion for detachably connecting the operating member. By connecting the operating member to the holding member by this connecting portion, the position and angle of the holding member of the pile lifting aid can be changed using the operating member, or the pile lifting aid itself can be moved. If the operating member is a rod-shaped member and the connecting portion is cylindrical, and the rod-shaped member is inserted into the cylindrical connecting portion, the angle of the holding member can be changed with a small force by the principle of leverage. In addition, by moving the pile lifting aid together while holding the rod-shaped operating member, work can be performed at a distance from the pile, which is safe. Note that the combination of the operating member and the connecting portion is not limited to the combination of a rod-shaped operating member and a cylindrical connecting portion as long as it is possible to perform operations such as changing the angle of the holding member. For example, a configuration in which a part of the operating member or one or both of the connecting portions are magnetized to fix the operating member to the holding member by magnetic force, or a configuration in which a recess is provided in the rod-shaped member and inserted into a protrusion provided in the connecting portion, may be used.

[0014] The holding member of the pile lifting aid of the present invention may have a restricting portion that restricts the rotation of the holding member when the portion that holds the pile is rotated to the top. With this configuration, the posture of the holding member is stabilized when the pile is lifted and released from the holding member, so that the shaking of the lower end of the pile can be suppressed. The restricting portion may be configured to restrict the rotation of the holding member. Examples of the restricting portion include a protruding portion that restricts the rotation of the main body by abutting against the main body, or a configuration that suppresses the rotation by sliding against the main body with a high friction coefficient. The restricting portion may also be provided on a support shaft that rotatably supports the holding member, or on a part of the holding member that abuts against the support shaft. Effect of the Invention

[0015] According to the present invention, the pile lifting auxiliary device can reduce the transmission of torsional force to the main body and properly maintain the lifting of the pile. [Brief description of the drawings]

[0016] [Figure 1] FIG. 13 is a diagram showing how a steel pipe is lifted. [Diagram 2] FIG. [Diagram 3] FIG. 13 is a diagram showing the state in which the hoisting cart holds a steel pipe. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] 13A and 13B are diagrams illustrating a state in which the angle of the holding member is adjusted. [Figure 8] FIG. 13 is a diagram showing the ability to accommodate rotation of a steel pipe. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, a pile lifting auxiliary device according to an embodiment of the present invention will be described with reference to the drawings. At the work site, the pile lifting auxiliary device is sometimes called a "drilling cart," so in the following description, the pile lifting auxiliary device will be referred to as a "drilling cart." The drilling cart is an auxiliary device that holds the lower end of a pile when erecting the pile. In the embodiment described below, an example will be given in which the drilling cart is used to lift a steel pipe pile, but the drilling cart of this embodiment can be used not only for steel pipe piles, but also for lifting steel sheet piles, steel pipe sheet piles, and the like.

[0018] FIG. 1 is a diagram showing how the derricking cart 1 is used. When erecting a steel pipe pile 30, a hook of a crane 50 is hung on one end of the steel pipe pile 30 and it is lifted up. The derricking cart 1 holds the other end of the steel pipe pile 30 and moves towards the crane 50 as the steel pipe pile 30 is erected. This allows the steel pipe pile 30 to be erected smoothly without the lower end of the steel pipe pile 30 being dragged on the ground. When the steel pipe pile 30 is further lifted after it has been completely erected, the lower end of the steel pipe pile 30 leaves the derricking cart 1, and the derricking cart 1 finishes its role of assisting in lifting the steel pipe pile.

[0019] Fig. 2 is a diagram showing the external appearance of the derricking cart 1 of this embodiment. The derricking cart 1 comprises a main body 10, wheels 13 attached to the main body 10, and two holding members 14 that hold the ends of the steel pipe piles 30. The holding members 14, also called "claws" on-site, have clamping portions 14a shaped like a two-pronged fork that clamp the ends of the steel pipe piles 30. In the following description, the direction in which the vehicle moves is referred to as the front-rear direction, and the direction in which the clamping portions 14a of the holding members 14 are located is referred to as the "forward" direction, as shown in Fig. 2.

[0020] Fig. 3 is a view of the hoisting trolley 1 of this embodiment as seen from the rear. Fig. 3 also shows a part of the steel pipe pile 30 held by the holding member 14. As shown in Figs. 2 and 3, the holding member 14 is rotatably supported at its rear by a support shaft 15. This allows the holding member 14 to rotate from a position in which the clamping portion 14a is in the forward position (this state is called the "initial state") until it is in the upward position. As shown in Fig. 2, the holding member 14 has a protruding portion 14b at its rearmost portion, and when the holding member 14 stands up, the protruding portion 14b comes into contact with the main body 10, thereby restricting the rotation.

[0021] The main body 10 is equipped with a base 11 having wheels 13, and a turntable 12 that is rotatable relative to the base 11. The turntable 12 is detachable from the base 11, and can be replaced with a base 11 with a different type of wheels, etc., depending on the conditions at the construction site. Although an example of a rafter 1 that runs on the ground is shown in Figures 2 and 3, there are also rafters that run on rails laid on top of existing piles. The configuration of the main body 10 differs between a rafter that runs on the ground and a rafter that runs on rails, but the configuration of the holding member 14 that holds the steel pipe piles 30 is the same.

[0022] In the descent vehicle 1 of this embodiment, the turntable 12 is detachable, so that by replacing it with another base 11 for running on rails, a descent vehicle 1 that runs on rails can be configured. Fig. 4 is a side view of the descent vehicle 1 running on rails, Fig. 5 is a top view of the descent vehicle 1, and Fig. 6 is a front view of the descent vehicle 1. Note that parts that are not visible in Figs. 4 to 6 are also shown in perspective. Also, in Figs. 4 to 6, components that correspond to those of the descent vehicle 1 shown in Figs. 2 and 3 are given the same reference numerals.

[0023] As described above, the configuration of the turntable 12 and the holding member 14 above the turntable 12 is the same for the hoisting cart shown in Figures 2 and 3 and the hoisting cart shown in Figures 4 to 6, so the holding member 14 will be described with reference to Figures 2 to 6.

[0024] The turntable 12 has fixing parts 16 to which a support shaft 15 is fixed. When the turntable 12 is not rotating, the support shaft 15 is perpendicular to the traveling direction of the hoisting cart 1. The support shaft 15 is fixed to fixing parts 16 provided on the turntable 12. The fixing parts 16 are located at three places in the width direction of the main body 10, on the left, right and center. The support shaft 15 is fixed to the left and right fixing parts 16 and is inserted into the center fixing part 16.

[0025] The two holding members 14 are attached to the support shaft 15 between the right fixing part 16 and the central fixing part 16, and between the left fixing part 16 and the central fixing part 16, so as to be rotatable and slidable. Figure 3 shows the range d within which each holding member 14 can slide. With this configuration, the two holding members 14 are arranged in parallel, are slidable in a direction that changes the spacing between them, and can rotate independently of each other.

[0026] Next, the clamping portion 14a of the holding member 14 will be described. As shown in Fig. 4, the upper surface 14c and the lower surface 14d of the clamping portion 14a that clamps the end of the steel pipe pile 30 are not horizontal in the initial state (when the clamping portion 14a faces forward), but are angled so as to become lower toward the center. Fig. 4 shows the holding member 14 on the right side, and this is why the upper surface 14c is visible. The upper surface 14c and the lower surface 14d are inclined in this manner in order to make the clamping portion 14a fit the arc shape of the end of the steel pipe pile 30.

[0027] Since the end of the steel pipe pile 30 is arc-shaped, the angle of the end to be held changes when the holding position shifts left or right. Referring to FIG. 3, it can be seen that as the position of the right holding member 14 shifts to the right, the angle of the part to be held gradually becomes closer to vertical. In this embodiment, the distance between the upper surface 14c and the lower surface 14d of the clamping portion 14a is configured to be slightly wider than the thickness of the steel pipe pile 30, so that the steel pipe pile can be clamped even if the left and right position is slightly shifted. This configuration, combined with the fact that the holding member is slidable, has the effect of allowing the selection of an appropriate holding position even for a steel pipe pile.

[0028] Each holding member 14 is provided with a cylindrical connecting portion 17. The connecting portion 17 has a role of inserting a rod-shaped operating member 40 and removably connecting the operating member 40 to the holding member 14. FIG. 7 is a diagram showing how the rod-shaped operating member 40 is inserted into the connecting portion 17 to move the holding member 14. By changing the angle and lateral position of the holding member 14 using the operating member 40 in this way, the position can be adjusted so that the clamping portion 14a appropriately clamps the end of the steel pipe pile 30. The angle of the holding member 14 can be easily changed by rotating it using the operating member 40 based on the principle of a lever. In addition, it is safe because the operation can be performed at a slight distance from the steel pipe pile 30.

[0029] Next, the unique configuration of the descent cart 1 (Figs. 4 to 6) that runs on rails will be described. The descent cart 1 that runs on rails is equipped with front and rear hooks 18, 19. The hooks 18, 19 are configured to couple with a driving cart. When moving forward, the front hook 18 is hooked onto the driving cart, and when moving backward, the rear hook 19 is hooked onto the driving cart, allowing the descent cart to be pulled by the driving cart. The descent cart 1 also has side wheels 20 that regulate its position in the width direction relative to the direction of travel.

[0030] The hoisting cart 1 of the present embodiment described above has the effect that the torsional force of the steel pipe pile 30 is not easily transmitted to the hoisting cart 1 because the two holding members 14 rotate independently. When the steel pipe pile 30 is hoisted, it is lifted by hanging two points on the pile head (see FIG. 1), but if the hanging position is not kept horizontal, a rotational force acts on the steel pipe pile 30. In such a case, as shown in FIG. 8, the two holding members 14 rotate independently, so one holding member 14 can rise to a position higher than the other holding member 14 by a height h, and the torsional force can be absorbed. This reduces the risk of the hoisting cart 1 tipping over. In addition, the two holding members 14 can slide in the width direction, so the torsional force can also be absorbed by the change in lateral position when the steel pipe pile 30 rotates.

[0031] Furthermore, when assisting in the lifting of a steel pipe pile 30 having a bit at its end, the hoisting cart 1 of this embodiment can hold the steel pipe pile 30 by sliding the two holding members 14 to avoid the position where the bit is located (see FIG. 3). In particular, when pressing into hard ground, a pile with a large number of bits (pilot pile) may be used, and even in the case of a pile with a large number of bits, the bottom end of the pile can be held appropriately. In addition, since the bottom end of the pile can be held while avoiding the fixing jigs for the liquid discharge hose provided inside and outside the end of the steel pipe pile and the gimmicks (such as unevenness) for the longitudinal joint of the steel pipe pile, a wider range of pile types can be accommodated than in the conventional configuration in which the interval between the holding members is fixed.

[0032] Although the pile lifting aid of the present embodiment has been described in detail above by way of an embodiment, the present invention is not limited to the above embodiment. In the above embodiment, the case where there are two holding members has been described, but the number of holding members is not limited to two, and may be three or more.

[0033] In the above embodiment, the pile lifting aid is described as having the holding member 14 rotate vertically, but if the direction from the support position of the holding member 14 by the support shaft 15 toward the clamping portion 14a is regarded as an axis, the holding member 14 may be configured to rotate around that axis. This can further absorb torsional forces. [Industrial Applicability]

[0034] INDUSTRIAL APPLICABILITY The present invention is useful as a pile lifting auxiliary device that holds the lower end of a pile when lifting the pile, such as a steel pipe pile, a steel pipe sheet pile, or a steel sheet pile. [Explanation of symbols]

[0035] 1. Hoisting trolley (pile lifting aid) 10 Main unit 11 Pedestal 12. Turntable 13 wheels 14 Retaining member 15 Support shaft 16 Fixed part 17 Connecting part 18 Hook 19. Hook 20 Side wheels 30 Steel pipe pile 31-bit 40 Operation member 50 Crane

Claims

1. A pile lifting aid that holds the bottom end of a pile when erecting the pile, The main body, Wheels attached to the body; A plurality of holding members arranged in parallel, the holding members rotating while holding the pile as the pile is erected; Equipped with The multiple holding members are used to hold piles, are slidable in a direction that changes the spacing between the piles, and rotate independently of each other in a pile lifting auxiliary device.

2. 2. A pile lifting aid as described in claim 1, further comprising a support shaft provided on an upper portion of said main body for supporting said holding member rotatably and slidably.

3. The body includes: A base having the wheels; The pile lifting aid according to claim 2 , further comprising a turntable having the support shaft and rotatable relative to the base.

4. The body includes: A base having the wheels; 3. A pile lifting aid as claimed in claim 2, further comprising a table having the support shaft and being detachable from the base.

5. 5. The pile lifting aid according to claim 1, wherein the holding member is provided with a connecting portion for detachably connecting an operating member thereto.

6. 6. A pile lifting aid as claimed in claim 1, wherein the holding member has a regulating portion that regulates the rotation of the holding member when the holding member is rotated until the portion holding the pile reaches the top.

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