JPH07108759B2 - Retractable crane - Google Patents

Description

Description: [Industrial field of use] The present invention relates to a retractable crane for loading and unloading a container in a retractable crane.

[Conventional technology]

The retractable crane consists of a mast provided on the base, a main boom rotatably attached to the lower part of the mast, a top boom that is rotatably attached to the tip of the main boom, and supports a suspended load. The tension boom that pulls the other end of the boom to the mat side, the lifting device that is suspended by the hoisting rope that is wound around the sheave provided at the tip of the top boom, the drum that hoists the hoisting rope, and the main boom It is equipped with a retraction device that performs extrusion retraction. Such a retractable crane is disclosed, for example, in JP-A-54-54.
67955, JP-A-54-122551 and JP-A-55-35765.

[Problems to be Solved by the Invention]

Such a retracting crane is generally used to carry a cargo by hanging a bucket or a hook.

Conventionally, when suspending a container, a first link is provided in parallel below the top boom, and the first link and the tip of the top boom are connected by a second link, and the first link is connected to the first link. A second sheave is provided at the connection point with the second link,
Two ropes are hung directly from the sheave at the tip of the top boom, and the other two ropes are hung from the sheave at the tip via the second sheave to perform four-point suspension. .

On the other hand, when suspending a bucket or a hook, the four ropes are directly suspended from the sheave at the tip excluding the first link, the second link, and the second sheave.

A crane in which luggage moves almost horizontally as the main boom retracts is called a horizontal retract crane.

The fact that the load moves horizontally does not require energy to pull in and push the load at a constant speed.

However, the mechanism is complicated to obtain a perfect horizontal trajectory, which is not practical.

Conventionally, a mechanism that is approximately horizontal has been adopted, but there has been no particular problem in bucket cargo handling and hook cargo handling.

This locus becomes an important issue when four-point suspension is performed during container handling because the container is long.

Since it is not a completely horizontal trajectory, the positions of the four hanging points change during the retracting operation, so the container tilts in the longitudinal direction, which is very dangerous during ground cutting and landing.

In addition, tilting of the hanger is desired in order to facilitate cargo handling.

An object of the present invention is to make a four-point suspension approach a completely horizontal trajectory to such an extent that it is not a problem in practical use, and to make it possible to tilt the suspending tool easily.

[Problems to be Solved by the Invention]

For the above purpose, a link is provided at the tip of the top boom, two of the four ropes that have passed through the sheaves at the tip of the top boom are directly connected to the hanger, and the other two ropes are provided at the link. Connect to the hanger via two sheaves,
Two ropes connected to the lower part of the mast are connected to the tip of the link via a fifth sheave installed in the middle of the mast and a sheave near the connection point between the main boom and the top boom, This can be achieved by movably providing the sheave of.

[Work]

The position of the fifth sheave installed on the mast is the vertical position of the sheave installed on the link.
Since it is set to a position that does not change much even if the turning radius changes due to extrusion, the lifting tool turns and the grounding and landing are performed with the longitudinal direction of the lifting tool (container) aligned with the boom direction. Since there is little inclination, there is no particular problem.

Also, if the sheave is moved, the hanger tilts.

〔Example〕

Hereinafter, details of the present invention will be described with reference to an embodiment shown in the drawings.

In FIG. 1, reference numeral 1 is a revolving structure mounted on a traveling structure 2 and revolving in a horizontal plane. The following device is mounted on the revolving structure 1. A main boom 5 is rotated by the retracting device 6. The retracting device 6 is attached to the mast 7. A top boom 8 is rotatably attached to the tip of the main boom 5. A tension boom 9 connects the rear end of the top boom 8 and the mast 7. 10 is a counterweight.

As shown in FIG. 1 to FIG. 6, four ropes 15a, 15 are provided at the side end of the mast 7, the rear end and the end of the top boom 8.
Subs, 17, 17, 18, and 19 through which b, 15c, and 15d pass are provided, respectively. The sheaves 16,17,18,19 each consist of four sheaves. Drum rope 15a, 15d passing through outer sheave 19a, 19d
I'm trying to wind it up to 21. The ropes 15b and 15c passing through the inner sheaves 19b and 19c are wound around the drum 22. 2
Reference numeral 5 denotes a sheave suspended from the tip of the top boom 8 by a link 26, and is operated by a rope 28 of a drum 27 installed on the revolving structure 2. The rope 28 is stretched from the sheave 69 installed on the mast 7 along the main boom 5, and is connected to the link 30 through the sheave 29 at the tip of the main boom 5. Link 30
Is coaxially connected to the sheave 25. The sheaves 25, 29, 69 each consist of two pieces, and are installed vertically below the ropes 15a, 15d. Each of the drums 21, 22, 27 can be operated independently.
The drums 21 and 22 can be operated in synchronization.

The structure around the sheave 25 at the tip of the top boom 8 will be described with reference to FIGS. 7 and 11. In the following description, the sheave 15a side will be described, but the sheave 19d side also has a similar configuration in principle. A link 26 is rotatably installed coaxially with the sheave 19 at the tip of the top boom 8. Link 26
A sheave 25 and a link 30 are rotatably installed at the tip of the. The sheave 25 and the link 30 are coaxial. Link 30
The rope 28 is connected to the tip of.

As shown in FIG. 11 (A), the link 26 is attached to the shaft 31 on both sides of the sheave 15a as a center. The cross section of the link 26 is H-shaped.

As shown in FIG. 11D, the sheave 25 is located at the center of the link 26, and the links 30 are located on both sides of the link 26. Board 36
Insert into the recess of shaft 35 and fix to link 26 with bolt 37,
The rotation and movement of the shaft 35 are prevented. The link 30 is composed of two plates, and the left and right two plates are fixed by bolts 41 via spacers to be integrated.

A roller 43 capable of supporting the rope 15a is provided on the upper surface side of the link 26.
Is provided. The roller 43 does not come into contact with the rope 15a or the sheave 26 in a steady state, but they are installed close to each other. First
As shown in FIGS. 11C and 11D, the length L of the shaft 44 that supports the roller 43 is sufficiently longer than the width 1 of the link 30. Also roller
43 can enter into the left and right plates of the link 30.

At the connecting ends of the ropes 15a, 15b, 15c, 15d to the hanger, connecting fittings including, for example, a cotter and a ket are provided. Second
Reference numeral 15f in FIGS. 3 and 4 shows a portion connected to the bracket of the suspender of the spreader 50 and the bucket 51 via a pin.
The sheave 52 for opening and closing the bucket 51 of FIG. 3 and the sheave 54 of the hook 53 of FIG. 4 are connected by ropes 55 between the connecting fittings of the ropes 55, respectively. 15g shows this connection. The connecting portion 15g is formed by connecting pins to the metal fittings of both ropes.

The cargo handling work in such a configuration will be described.

First, the ropes 15a and 15d are moved from the sheaves 19a and 19d to the sheaves 25a and 25d.
Suspend over b. In this case, the roller 43 is attached through the hole 48 of the link 26 as shown in FIG. 11 (B). Link 30
Connect the rope 28 to. Rope 15b, 15c is sheave 19b, 19c
Hang from.

When suspending the spreader 50 as a suspender for the container, the rope 28 is also wound on the drum 27 and the rope 15
Wind up b and 15c on the drum 22 and pull them so that the spreader becomes horizontal. The drum 27 is fixed in that state. Since sheave 25 is pulled by rope 28, ropes 15a, 15d
Means that the ropes are suspended substantially parallel to the ropes 15b and 15c, and the spacing between the suspension points for suspending four points can be maintained.

Then, by operating the drums 21 and 22 in synchronization,
The height of the spreader 50 can be adjusted.

The spreader 50 is moved substantially horizontally by the operation of the retractor 6. In this case, if the sheave 29 is provided at the connection point between the top boom 8 and the main boom 5, the spreader
The 50 never tilts. However, it is difficult to provide the sheave 29 at the center of rotation of the top boom 8.
As shown in the figure, when the rotation center 49 of the top boom 8 and the sheave 29 are mounted (provided on the top boom 8), the spreader 50 tilts if the length of the rope 28 is constant.

The sheave 29 is mounted at a position where it is structurally easy to install, and the sheave 69 is installed at a position where the amount of inclination of the spreader 50 is not harmful.

Next, the case of suspending the bucket 51 and the hook 53 will be described. In this case, as shown in FIG. 3 and FIG.
Loosen the rope 28 sufficiently using. And sheave 52,5
The rope 55 for 4 is connected and also connected to the hanger. The length of the rope 15 is adjusted so that the bucket 51 and the hook 53 are horizontal by operating the drums 21 and 22 as appropriate. When the hoisting equipment is hoisted up, the sheave 25 is moved by the tension of the ropes 15a and 15d, as shown in FIG.
As shown in Fig. 10, it moves to the outside of the sheave 19 and the rope 15a,
15d hangs vertically.

When the top boom 8 is set to the minimum radius, as shown in FIG. 10, the sheave 25 is located outside the center line P connecting the sheaves 18 and 19, so that the rope 28 is directly attached to the shaft 35 of the sheave 25. Then, the rope 28 comes into contact with the sheaves 19a and 19d, or enters between the sheaves 19a and 19b and the top boom 8, and the rope 28 is damaged.

Therefore, the link 30 is provided so that the rope 28 is located inside the sheave 19. However, the link
30 is pulled by rope 28 and tends to be parallel to link 26. This is because the weight of the link 30 is lighter than the rope 28, and the distance between the drum 27 and the sheave 29 is longer than that between the sheave 29 and the sheave 25. Therefore, the length L of the shaft 44 is set to the width l of the link 30.
Longer so that link 30 does not strike axis 44 and be parallel to link 26. As a result, the rope 28 is always located inside the sheave 19.

When the top boom 8 is extended from the inner side to the outer side (or vice versa) and stopped, the ropes 15a and 15b may come off from the sheave 25, and the roller 43 prevents this. This roller 43
Since the shaft 44 is also used as a positioning stopper for the link 30, the number of members can be reduced, and the weight and cost can be reduced.

As described above, since the sheave 25 for hanging four points is operated by the rope 28, it is possible to change the hanging points extremely easily and safely when replacing the hanging tool.

Further, since the link 30 is provided between the sheave 25 and the rope 28, and the stopper (shaft 44) for adjusting the angle of the link 30 is provided on the link 26, the rope 28 will not move when the bucket or hook is hung. It is possible to prevent contact with the sheave 19. The link 30 need not be coaxial with the sheave 25. As a stopper, a roller 70 may be provided so as to project to the rope 28 side of the boom 8 so as to prevent the rope 28 from coming into contact with the sheave 19, as shown in FIG. Of course, a stopper is required to prevent the link 30 from being parallel to the link 26.

Further, since the stopper is also used as the shaft of the roller 43 for preventing the disengagement, the cost can be reduced.

In the case of two-point suspension of the hook 53 or the like, the sheave 25 can be pulled by the rope 28 so that the rope from the sheaves 19 and 25 to the suspender (hook 53) can be diagonally arranged and used.

Since the sheave 69 is installed between the sheave 29 and the drum 27, the levelness of the spreader 50 can be kept substantially constant regardless of the hoisting angle of the main boom 5. The drum 27 may be provided at the position of the sheave 69, but it is practically impossible to provide the large drum 27 at the position of the sheave 69. Since the sheave 69 is smaller than that, it can be easily installed in the optimum position.

As is well known, the length of each link of the double-link type crane and the trajectory of the hanger are obtained by trial and error. The calculation of the optimum position of the sheave 69 is similar to this.

Another embodiment shown in FIGS. 2, 3, and 4 will be described. The sheaves 69, 69 are movable in the axial direction by a drive device (for example, cylinder devices 70, 70). If the spreader 50 is tilted when the spreader 50 is landed on the floor, the driver drives the drive devices 70, 70 to change the positions of the sheaves 69, 69 to correct the tilt amount of the spreader 50. The two drive devices 70, 70 operate at the same time by the same amount to reduce or separate the two sheaves 69, 69 from each other.

The sheaves 69, 69 may be moved in the radial direction.

〔The invention's effect〕

According to the present invention, when four-point suspension is performed, it is possible to approach a completely horizontal locus to the extent that there is no practical problem.
The slant in the longitudinal direction of the suspension is reduced, and safe work can be performed even when cutting the ground and landing. In addition, tilting of the hanging device can be easily performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall front view of a retractable crane, FIG. 2 is a perspective view showing the arrangement of ropes when suspending a spreader, and FIG. 3 is a perspective view showing the arrangement of ropes when suspending a bucket. Figure, 4th
The figure is a perspective view showing the arrangement of ropes when suspending the hook, Fig. 5 is a front view around the top boom, Fig. 6 is a view showing the arrangement of sheaves of the top boom, and Fig. 7 is a case where the spreader is suspended. Fig. 8 is a front view of the tip of the top boom when the top boom is at the maximum radius. Fig. 8 is a front view of the tip of the top boom when the spreader is hung and the top boom is at the minimum radius. Fig. 9 is a hook. Front view of the tip of the top boom when the top boom is set to the maximum radius when hanging the hook, and Fig. 10 is a front view of the tip of the top boom when the hook is hung and the top boom is set to the minimum radius. 11
The drawing is a sectional view taken along the line ABC in FIG. 2 ... Revolving structure, 5 ... Main boom, 6 ... Retractor,
7 …… Mast, 8 …… Top boom, 9 …… Tension boom, 15,15a, 15b, 15c, 15d …… Rope, 16,17,18,19,
19a, 19b, 19c, 19d, 25,29 …… sheave, 21,22,27 …… drum, 28 …… rope, 43 …… guide roller, 44 …… axis, 50
…… Spreader, 51 …… Bucket, 53 …… Hook, 69…
… Guide sheave

Continuation of front page (56) Reference JP-A-59-108693 (JP, A) JP-A-61-81390 (JP, A) JP-A-61-119595 (JP, A)

Claims (1)

[Claims] 1. A mast, a main boom rotatably attached to a lower portion of the mast in a vertical direction, a top boom rotatably attached to an end of the main boom, a rear end of the top boom and an upper portion of the mast. A tension boom that is rotatably attached between the top boom and a link that is rotatably hung vertically from the tip of the top boom, and the four ropes extended from the drum installed on the mast are The four first sheaves on the upper part of the mast, the four second sheaves at the connection point between the tension boom and the top boom, and the four third sheaves at the tip of the top boom are hung through in order, Of the four ropes, two ropes are hung via the third sheave and then the fourth sheave at the tip of the link, and are installed at the bottom of the mast. The rope, two fifth sheave installed in the middle of the mast, the two in the vicinity of the connecting point between the main boom and the top boom 6
And a moving means for moving the fifth sheave, wherein the retractable crane is connected to the tip end side of the link via the sheaves in sequence.